Possui graduação (2001) e doutorado (2005) em Eng. Metalúrgica e de Materiais pela Technische Universität Berlin, na Alemanha. Realizou Pós-Doutorado no Instituto de Ciência e Tecnologia dos Materiais da Technische Universität Wien, em Viena, na Austria. Liderou por quase 04 anos (2006-2009) um Grupo de Pesquisa na área de Propriedades Mecânicas e Caracterização Não-Destrutiva de Materiais por Difração de raios-X no Max-Planck Institut für Eisenforschung, em Düsseldorf, na Alemanha. É Professor Livre Docente (MS-5.3) na área de Metalurgia Física do Departamento de Engenharia de Materiais (SMM) da Escola de Engenharia de São Carlos (EESC) da Universidade de São Paulo (USP), campus São Carlos. Desde Agosto de 2021, realiza um período sabático de 12 meses como Professor Visitante no MikroTribologie Centrum μTC do Karlsruher Institut für Technologie (KIT) na Alemanha, com financiamento da FAPESP e do European Research Council (ERC). É orientador com credenciamento pleno em 02 Programas de Pós-Graduação da USP: em Ciência e Engenharia de Materiais (Conceito 6 da CAPES) e em Engenharia Mecânica (Conceito 5 da CAPES). Coordena o Centro de Pesquisa e Análise de Materiais de Engenharia (CEPAME), uma Central de Equipamentos Multiusuários da USP: https://uspmulti.prp.usp.br/centrais/editar_cadastro/75. O CEPAME atua no estudo da correlação entre os processos de manufatura dos materiais de engenharia do binômio metal-cerâmica, as transformações de fase e a formação da microestrutura, das tensões residuais e da textura cristalográfica nos materiais com aplicações estruturais, tribológicas, biomédicas e de armazenamento de hidrogênio, entre outras. O CEPAME emprega métodos avançados de caracterização, tais como técnicas in-situ com luz sincrotron e a difração de raios-X e de elétrons, para elucidar e compreender as correlações entre a composição, a estrutura, a manufatura e as propriedades dos materiais, recobrimentos e superfícies de engenharia. É Editor Associado do periódico Frontiers in Materials (JOURNAL IMPACT FACTOR 2020 3.515), section Structural Materials. Atua no Comitê de Avaliação de Propostas de Difração de Raios-X do LNLS-CNPEM. Em 2021 foi eleito membro do Comitê de Usuários do LNLS pela Comunidade Brasileira de Engenheiros de Materiais interessados no uso das novas técnicas avançadas de caracterização e nas energias mais elevadas disponíveis na nova fonte de luz síncrotron brasileira, o SIRIUS. Atua como Revisor em mais de 15 Periódicos Internacionais com JCR. Atua nas áreas de Processos de Manufatura de materiais metálicos, Engenharia de Superfícies, Propriedades Mecânicas dos Materiais e Caracterizaçao Microestrutural, com ênfase em Metalurgia Física, Soldagem, Desgaste, Corrosão à Elevadas Temperaturas e Métodos de Difração com raios-X de laboratório, luz síncrotron e neutrons, assim como com elétrons retroespalhados no MEV-FEG.

Graduated (2001) and Ph.D. (2005) in Metallurgical and Materials Engineering at the Technische Universität Berlin, Germany. He held a Post-Doctoral stage at the Institute of Materials Science and Technology of the Technische Universität Wien, Vienna, Austria. He led for almost 04 years (2006-2009) a Research Group in the field of Mechanical Properties and Non-Destructive Materials Characterization using X-Ray Diffraction at the Max-Planck Institut für Eisenforschung, in Düsseldorf, Germany. He is Associate Professor, on a tenure track pathway, for the chair of Physical Metallurgy at the Department of Materials Engineering (SMM) at the São Carlos School of Engineering (EESC) of the University of São Paulo (USP), São Carlos campus. Since August 2021, he has been taking a 12-month sabbatical as Visiting Professor at the MikroTribologie Centrum μTC of the Karlsruher Institut für Technologie (KIT) in Germany, with funding from FAPESP and the European Research Council (ERC). He is a fully accredited advisor in 02 Graduate Programs of the USP: in Materials Science and Engineering (CAPES Concept 6) and Mechanical Engineering (CAPES Concept 5). He coordinates the Center for Research and Analysis of Engineering Materials (CEPAME), a Center for Multiuser Equipments at USP:

https://uspmulti.prp.usp.br/centrais/editar_cadastro/75

CEPAME works on the study of the correlation between the manufacturing processes of engineering materials from the metal-ceramic binomial, the phase transformations and the formation of microstructure, residual stresses and crystallographic texture in materials for structural, tribological, biomedical and hydrogen storage applications, among others. CEPAME employs advanced characterization tools, such as in-situ techniques with synchrotron light as well as lab X-ray and electron diffraction, to elucidate and understand the correlations between the composition, structure, manufacture and properties of engineering materials, coatings and surfaces. He is Associate Editor of the journal Frontiers in Materials (JOURNAL IMPACT FACTOR 2020 3.515), section Structural Materials. He serves on the LNLS-CNPEM’s X-Ray Diffraction Proposal Evaluation Committee. In 2021, he was elected a member of the LNLS Users Committee by the Brazilian Community of Materials Engineers interested in the use of new advanced characterization techniques and the highest energies available in the new Brazilian synchrotron light source, SIRIUS. He serves as a Reviewer in more than 15 International Journals with JCR. He works on the Manufacturing Processes for metallic materials, Surface Engineering, Mechanical and Tribological Properties as well as Microstructural Characterization, with an emphasis on Physical Metallurgy, Welding, Wear, High-Temperature Corrosion and Diffraction Methods with lab X-rays, synchrotron light and neutrons, as well as with backscattered electron in the FEG-SEM.

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2021 – Atual – Estudos avançados da relação microestrutura-propriedade de mono- e multicamadas de Cr-Al-N para a melhoria do desempenho tribológico em motores de combustão (Proc.: 2019/14262-3) (Valor: R$ 11.160,00 + US$ 48.080,34)

Descrição: Os filmes CrN e CrAlN são amplamente utilizados em anéis de pistão, a fim de melhorar seu desempenho em motores de combustão. Esta aplicação extensiva é corroborada pela sua boa resistência à oxidação, elevada dureza, inércia química e resistência ao desgaste. A combinação de todas essas propriedades é altamente atrativa para aplicações nas indústrias de ferramentas, automotiva, aeroespacial e decorativa. Hoje em dia, a melhoria das propriedades mecânicas e térmicas de revestimentos de CrN crescidos monoliticamente pode ser alcançada por meio de solução solida com diferentes elementos, como o Al. Os métodos de PVD para a deposição de mono- e multicamadas de Cr-Al-N permitem gerar uma variedade de microestruturas significativas para o desempenho mecânico e tribológico de sistemas de revestimento. Em especial, perfis composicionais químicos, distribuição granulométrica, arquitetura do revestimento, tensões residuais/térmicas e a textura cristalográfica permitem otimizar as propriedades mecânicas e o desempenho tribológico dos revestimentos à base de Cr-Al-N. O objetivo deste projeto é, portanto, contribuir para o entendimento de como parâmetros específicos de deposição por DC-MS e HiPIMS determinam microestruturas selecionadas e propriedades mecânicas com especial interesse no desempenho/resposta tribológica de revestimentos à base de Cr-Al-N. As mono- e multicamadas à base de Cr-Al-N obtidas pelos métodos DC-MS e HiPIMS serão depositadas em substratos de aço inoxidável e comparadas. Os aços inoxidáveis são escolhidos devido à sua diversidade de aplicações, como matrizes, motores e ferramentas de corte. As microestruturas produzidas por rotas distintas de PVD serão caracterizadas utilizando ferramentas avançadas, como GDOES, TKD, EBSD, STEM, tomografia FIB-SEM-EBSD e difração de raios-X (DRX) com luz sincrotron. Para avaliar as propriedades mecânicas e tribológicas, análises de tensão serão realizadas usando DRX e ensaios de desgaste e atrito com a configuração de esfera sobre disco serão conduzidos em temperatura ambiente e elevadas temperaturas, bem como em ambientes erosivos-corrosivos..

Situação: Em andamento; Natureza: Pesquisa.
Alunos envolvidos: Doutorado: (2).
Integrantes: Haroldo Cavalcanti Pinto – Coordenador / Christian Greiner – Integrante.
Financiador(es): Fundação de Amparo à Pesquisa do Estado de São Paulo – Bolsa.

2018 – 2019 – Thermomechanical processing of emerging metallic materials (Proc.: PROBRAL 88881.143948/2017-01) (Valor: R$ 200.000,00)

Descrição: Advanced high strength (AHS) steels, magnesium and titanium alloys are used for structural elements in transportation and sporting goods. Their advantages are high specific stiffness and strength, particularly under bending loads, assets that go along with the industrial efforts of weight reduction and low emissions. Austenitic stainless steels have a wide range of applications because of their high temperature strength caused by the precipitation of second-phase, along with resistance to carburizing, corrosion and oxidation in different environments. The capability of multiphase alloys to withstand external loads is determined by the mechanical and physical properties of the microstructural components, their thermal/mechanical stability and their geometrical arrangement. All these parameters vary during production and service. Therefore, physical aspects such as nucleation and growth of phases, grain re-orientation, phase-specific stresses, diffusion controlled morphological changes or bonding of interfaces must be considered to understand the thermomechanical behavior of the alloys. Furthermore, microstructural features influence the stress partition between phases, stress localization as well as possible damage nucleation and evolution. The sensitivity of the mechanical properties to microstructural changes in structural steels, magnesium and titanium alloys has been studied and reported but new insights can be gained nowadays due to the advance of modern characterisation methods that allow to observe the evolution of the microstructure in-situ and/or three-dimensionally. In order to improve the mechanical properties of such alloys, hot forming processes have been studied for grain refinement. They promote microstructural modification due to dynamic recrystalization and texture evolution. Besides this, the thermomechanical effect during hot stamping, in which the tool is cooled during the forming step, is another aspect that must be taken into account since this has been largely used and studied mainly in the automotive industries. This project concentrates on the investigation of the formation and evolution of 3D multiphase arrangements, phase-specific texture and stresses in selected Nb-microalloyed steels, magnesium and titanium alloys during thermomechanical treatments, thus aiming at controlling their microstructure and thermomechanical response. This requires the use of computational thermodynamics to pre-screen potential alloying elements for iron systems, advanced 3D high-resolution imaging methods to reveal the architecture of the alloys and in-situ synchrotron X-ray diffraction combined with a Gleeble simulator at the XTMS beamline of LNLS to follow the formation and evolution of microstructural phases as well as their specific preferential grain orientations and stresses during different thermomechanical processes.

Situação: Concluído; Natureza: Pesquisa.
Alunos envolvidos: Doutorado: (6).
Integrantes: Haroldo Cavalcanti Pinto – Coordenador / Rodrigo S. Coelho – Integrante / Soldera, Flavio – Integrante / Mücklich, Frank – Integrante / Pedro Paiva Brito – Integrante.
Financiador(es): CAPES – Centro Anhanguera de Promoção e Educação Social – Cooperação.

2017 – 2020 – Propriedades estruturais e tribológicas de mono- e multicamadas cerâmicas contendo Cr e Al obtidas pelo processo High Power Impulse Magnetron Sputtering (Proc.: 409545/2016-3) (Valor: R$ 43.000,00)

Descrição: O objetivo deste projeto é o desenvolvimento de camadas de recobrimento à base de CrN e Cr1-XAlXN a serem depositadas sobre substrato de aço inoxidável martensítico 440 nitretado utilizando o processo de deposição HiPIMS (High Power Impulse Magnetron Sputtering). Os substratos foram fornecidos pela empresa MAHLE Metal Leve, interessada neste desenvolvimento. O desafio em se estabelecer o processo HiPIMS está relacionado à sua maior complexidade, que se deve ao maior número de parâmetros envolvidos, se comparado ao processo comercial de vaporização por arco catódico. Enquanto na vaporização por arco catódico a deposição é determinada principalmente pela corrente de descarga, a tecnologia HiPIMS requer a otimização da forma de pulsação da fonte de potência. Isso inclui o ajuste da configuração de tempos de polarização (ton) e despolarização (toff) dos alvos, assim como da corrente de pico para cada potência média aplicada no alvo, além dos parâmetros comuns aos processos de deposição física, tais como pressões parciais de gás no reator, temperatura e polarização negativa (bias) do substrato. O método de deposição física HiPIMS possibilita a obtenção de compostos com alta pureza e controle estrutural, tanto no nível atômico como na escala nanométrica. O ajuste preciso dos parâmetros de processo permite a deposição de monocamadas, multicamadas, nanocompósitos, nanoestruturas funcionalizadas e partículas para diversas aplicações. Atualmente, os nitretos de metais de transição têm sido muito estudados para aplicações que requerem resistência ao atrito, ao desgaste, à corrosão e à oxidação. Dentre estes compostos, o nitreto de cromo (CrN) se destaca por possuir grande importância tecnológica. Suas propriedades mecânicas e tribológicas e sua relativa facilidade de deposição faz deste material único para diversos usos, como recobrimentos duros e, mais recentemente, implantes médicos. A pesquisa proposta neste projeto consiste no desenvolvimento do processo HiPIMS para a deposição de filmes de CrN e Cr1-XAlXN, além de multicamadas de CrN/ Cr1-XAlXN com superestrutura com o objetivo de obter recobrimentos duros e nanoestruturados com elevada área interfacial e boa tenacidade, utilizando alvos metálicos de Cr e ligas de CrAl (50-50, 30-70, 70-30%at), além de misturas gasosas de nitrogênio e argônio como precursores dos recobrimentos. As camadas obtidas serão caracterizadas por uma combinação de diversas técnicas, tais como Difração de Raio-X, MEV-EDS-EBSD, MET, AFM, XPS, perfilometria óptica, nanodureza instrumentada e testes de riscamento e desgaste, a partir das quais será possível correlacionar as propriedades mecânicas e tribológicas com a micro e a nano estrutura do recobrimento depositado.

Situação: Concluído; Natureza: Pesquisa.
Alunos envolvidos: Graduação: (2) / Mestrado acadêmico: (1) / Doutorado: (1).
Integrantes: Haroldo Cavalcanti Pinto – Coordenador / Fernando Alvarez – Integrante / Alisson Mendes Rodrigues – Integrante / Viviane Oliveira Soares – Integrante.
Financiador(es): Conselho Nacional de Desenvolvimento Científico e Tecnológico – Auxílio financeiro.

2015 – 2019 – CREATe-Network: Processing and Characterization of Advanced Composites for Resource-Efficient Applications and Technologies

Descrição: CREATe-Net is composed of 3 academic institutions in Europe (Saarland Univ., DE; Technical Univ. of Catalonia, ES; and INM – Leibniz Institute for New Materials, DE), 3 non-academic institutions in Europe (AB Sandvik Coromant, SE; Steinbeis Research and Innovation Centers, DE; and Nanoforce Ltd., UK), as well as 6 academic partners outside Europe (CSIR – Council for Scientific and Industrial Research, ZA; Univ. Católica de Uruguay, UY; Instituto de Investigaciones en Ciencia e Ingeniería de Materiales, AR; Univ. de Concepción, CL; Univ. de Sao Paulo, BR; and Georgia Institute of Technology, US). The network will cooperate in the field of design, processing and characterization of novel composite materials for resource-efficient applications and environmentally friendly technologies, in particular energy storage, bearings, electrical contacts, and cutting tools. The purpose of the network is to combine different thematic expertises of the academic and industrial network members in the multidisciplinary field of materials science and engineering in order to design new composite materials with superior properties and performance. The expertise of the network includes: a) design by modelling at different scales (e. g. atomistic modelling, thermodynamic and kinetic modelling, finite element modelling); b) novel processing methods (e . g. atomic layer deposition, severe plastic deformation and rapid solidification); c) advanced characterization methods (e. g. serial sectioning and atom probe tomography, high resolution transmission electron microscopy); d) processing/characterization of carbon materials, metal and ceramic matrix composites as well as functionally graded materials; and e) performance testing for targeted applications (available through special designed testing facilities at the research centres and industrial partners). Two workshops and one final conference will contribute to the exchange of knowledge beside the exchange of researchers.

Situação: Concluído; Natureza: Pesquisa.
Integrantes: Haroldo Cavalcanti Pinto – Integrante / F. Mücklich – Coordenador / Soldera, Flavio – Integrante / José García – Integrante.

2014 – 2017 – Microstructural engineering of structural light alloys (Proc.: 407399/2013-5) (Valor: R$ 140.800,00)

Descrição: The proposed project concentrates on the investigation of the formation and evolution of three-dimensional multiphase arrangements of selected structural aluminium, magnesium and titanium alloys during thermal and/or thermo-mechanical treatments aiming at controlling their microstructure and, consequently, their thermo-mechanical behaviour. This will require the use of state-of-the-art ex situ and in situ 3D imaging methods to reveal the internal architecture of the alloys together with in situ bulk diffraction methods to follow the formation and evolution of microstructural phases as well as their evolution and load carrying capability during different loading conditions.

Situação: Concluído; Natureza: Pesquisa.
Integrantes: Haroldo Cavalcanti Pinto – Coordenador / Guillermo Carlos Requena – Integrante.

Financiador(es): Conselho Nacional de Desenvolvimento Científico e Tecnológico – Cooperação.

2011 – Atual – Núcleo de Apoio à Pesquisa em Materiais Avançados (NAP-MA) da USP (Valor: R$ 900.000,00)

Descrição: A missão do NAP-MA é criar um ambiente inter e multidisciplinar e de intensa colaboração de pesquisa, desenvolvimento e inovação em materiais híbridos, agregando competências nas áreas de materiais cerâmicas (policristalinas e vítreas), metais, polímeros e compósitos existentes no SMM/EESC/USP, mais a capacidade patente desse departamento em ensaios mecânicos e tribológicos, e ainda a competência no estudo da física e química da matéria condensada do Grupo de Crescimento de Cristais e Materiais Cerâmicos do IFSC/USP, para o estudo e desenvolvimento de materiais envolvendo suas inter-relações, tanto na etapa de processamento como na geração de materiais híbridos propriamente ditos, com propriedades superiores.

Situação: Em andamento; Natureza: Pesquisa.
Integrantes: Haroldo Cavalcanti Pinto – Integrante / Antônio Carlos Hernandes – Coordenador / Antônio José Felix de Carvalho – Integrante / Vera Lúcia Arantes – Integrante / Rafael Salomão – Integrante / Marcelo A. Chinelatto – Integrante / Márcia Cristina Branciforti – Integrante / Eduardo Bellini Ferreira – Integrante.
Financiador(es): Universidade de São Paulo – Auxílio financeiro.

2011 – 2015 – Junção por Fricção e Mistura Mecânica em Ligas Tixofundidas de Magnésio de Alto Desempenho (Proc.: 2010/11391-2) (Valor: R$ 168.648,20 + US$ 232.322,17)

Descrição: O presente projeto tem como objetivo estudar a soldabilidade por fricção e mistura mecânica (SFMM) de novos materiais leves e recicláveis de elevado desempenho à base da liga de magnésio ZK60 (Mg-6%Zn-1%Zr) modificada com diferentes teores de mischmetal (ZK60-RE): 0.5, 1.5 e 2.5 % em peso. Para a obtenção de tais materiais ainda inexplorados no Brasil propõe-se a utilização da fundição de semi-sólidos sob agitação mecânica, combinada a tratamentos térmicos do tipo T4, T5 ou T6. A liga ZK60 representa uma importante matriz para o desenvolvimento de materiais com aplicações em estruturas aeronáuticas mais leves, já que oferece a maior resistência mecânica específica dentre as ligas de magnésio tradicionais, aproximando-se da liga de alumínio 7075. A sua modificação através da adição de terras raras visa formar intermetálicos de elevado ponto de fusão e estabilidade termoquímica necessários ao aumento da resistência mecânica a temperatura ambiente e também a temperaturas mais elevadas; além da resistência à corrosão e à oxidação. Já o zircônio atua no refino de grão em fundidos de magnésio, aumentando o potencial destes materiais para uma moldagem definitiva através da fundição de semi-sólidos. A influência dos parâmetros de fundição, tratamento térmico e junção será quantificada na microestrutura, nas propriedades mecânicas, no comportamento em meios corrosivos e na oxidação das ligas e suas juntas soldadas por fricção e mistura mecânica.

Situação: Concluído; Natureza: Pesquisa.
Alunos envolvidos: Graduação: (3) / Doutorado: (1).
Integrantes: Haroldo Cavalcanti Pinto – Coordenador / Antonio J. Ramirez – Integrante / Ricardo Henrique Buzolin – Integrante / Erenilton Pereira da Silva – Integrante / Larissa Fernandes Batista – Integrante / Bruna Callegari – Integrante.
Financiador(es): Fundação de Amparo à Pesquisa do Estado de São Paulo – Auxílio financeiro.

2010 – 2013 – NanoCom-Network: Advanced Processing and Characterisation of Micro and Nano Composites (Valor: US$ 32.000,00)

Descrição: Advanced materials consisting of many constituents such as metal matrix composites, cellular materials, graded materials and eutectic alloys are continuously improved in order to tailor their properties and comply with specific application requirements. These materials are finding more and more technological applications where high performance of materials is required and especially when light weight is an important factor. Composite materials offer unique mechanical and physical properties as a result of the interaction between their constituents but primarily by their geometrical arrangement, i.e. internal architecture. A 3D approach is absolutely necessary to understand how the architectural features influence the physical behaviour of heterogeneous materials. Furthermore, if the 3D architecture resulting from the combination of material constituents is known, this information can be capitalized to design new heterogeneous materials with tailored and high performance properties. In the present project, different processing techniques will be utilised and further developed. Furthermore, new characterisation techniques in all length scales such as FIB-tomography, atom probe tomography, synchrotron tomography and synchrotron XRD will be optimised for the special use in the characterisation of composites. Within the broad field of composite materials in the micro as well as in the nano scale, we will concentrate on the following systems and aspects: 1) Advanced design of highly functionalised carbon nanotubes (CNT) reinforced composites; 2) Advanced design of Al-MMC and effects of interfaces; 3) Advanced production and characterisation of nano-structured bulk metal-ceramic composites; 4) Advanced production and characterisation of nano-structured coatings; 5) MMCs reinforced with diamond particles; 6) Modern and 3D characterisation of MMC.

Situação: Concluído; Natureza: Pesquisa.
Alunos envolvidos: Doutorado: (1).
Integrantes: Haroldo Cavalcanti Pinto – Coordenador / J. Garcia – Integrante / Waldek Bose Filho – Integrante / Luiz Carlos Casteletti – Integrante / José Ricardo Tarpani – Integrante / Marcelo Falcão – Integrante / Augusta Isaac Neta Pinto – Integrante.
Financiador(es): União Européia – Programa FP7 – Auxílio financeiro.

2010 – 2012 – Obtenção e caracterização de juntas dissimilares por fricção e mistura mecânica entre aços automotivos TWIP e ARBL (Proc.: 474718/2010-7) (Valor: R$ 40.395,00)

Descrição: Trata-se de um projeto tecnológico para estudar a soldabilidade de novos aços alto Mn austeníticos com efeito de plasticidade induzida por maclação (TWIP) com aços microligados de alta resistência e baixa liga (ARBL) pela tecnologia de fricção e mistura mecânica (Friction Stir Welding). Apesar de reunirem resistência mecânica extraordinária e grandes alongamentos, os aços TWIP impõem desafios aos processos convencionais de soldagem por fusão, quando considerados para a produção de estruturas veiculares leves soldadas sob medida. Isso se deve à sua microestrutura austenítica e ao seu alto teor em elementos de liga, os quais favorecem a formação de fases frágeis na zona de fusão, assim como de elevadas tensões residuais no cordão de solda e nas zonas termicamente afetadas, durante a união com aços comerciais de baixa liga e predominantemente ferríticos. Tendo em vista que os aços TWIP ainda não se encontram disponíveis comercialmente, serão produzidos em escala laboratorial dois tipos de aço TWIP utilizando-se composições químicas já bem estabelecidas na literatura científica internacional. A rota de processamento será aquela utilizada tradicionalmente para aços austeníticos inoxidáveis e também documentada na literatura para os aços TWIP, i.e. fundição seguida de homogeneização e conformação mecânica a quente por forjamento. Já os aços ARBL, a serem usados na produção das juntas dissimilares, serão duas ligas comerciais para conformação a frio fornecidas pela ThyssenKrupp Aceros y Servicios S.A.. As juntas soldadas serão produzidas com dois aportes térmicos distintos, variando-se a velocidade de rotação da ferramenta. O impacto do aporte térmico na soldagem por fricção e mistura mecânica (SFMM) de aços TWIP com aços ARBL será avaliado com relação às propriedades mecânicas das juntas, aos seus gradientes microestruturais, aos aspectos morfológicos das suas superfícies de fratura, bem como com respeito ao estado de tensões residuais.

Situação: Concluído; Natureza: Pesquisa.
Alunos envolvidos: Graduação: (1) / Mestrado acadêmico: (2).
Integrantes: Haroldo Cavalcanti Pinto – Coordenador / Antonio J. Ramirez – Integrante / Omar Maluf – Integrante.
Financiador(es): Conselho Nacional de Desenvolvimento Científico e Tecnológico – Auxílio financeiro.
Número de produções C, T & A: 3

2008 – 2011 – Wear Protecting Nanostructured Coatings for Cutting Processes

Descrição: The productivity as well as the lifetime of cutting tools can be considerably increased by combining suitable technologies to modify the surface of the substrate prior to coating coupled with new multiphase nanostructured coatings. This project is a DFG research grant for German-Brazilian cooperation aiming at understanding the mechanisms of wear, corrosion, phase transformations and damage initiation in novel wear protecting nanocoatings. At MPIE Dr. J. Garcia will guide the production of coatings with tailored microstructures (graded, multilayer and composite) by thermodynamic simulations and cutting tests. Dr. H. Pinto will be responsible for the microstructure and residual stress assessment in the coated tools. The Brazilian partners will pre-treat the substrates by noble gas bombardment (UNICAMP) and characterize the resulting microstructures and residual stresses of the modified substrates (Brazilian Synchrotron Light Laboratory, LNLS).

Situação: Concluído; Natureza: Pesquisa.
Integrantes: Haroldo Cavalcanti Pinto – Coordenador / J. Garcia – Integrante / Roosevelt Droppa Jr. – Integrante / Fernando Alvarez – Integrante.
Financiador(es): Deutsche Forschungsgemeinschaft – Auxílio financeiro.

2007 – 2009 – Defects and Internal Stresses in Novel Austenitic high-Mn Steels

Descrição: The deformation behavior (TRIP/TWIP) of austenitic high-Mn steels is influenced by the steel composition and the temperature which change the stacking fault energy (SFE) of the austenitic lattice. In addition to the SFE, the level of deformation and the multiaxiality of the stress state also affect the deformation mechanisms of the austenite. On the other hand, the manufacturing and service of mechanical components from high-Mn steels are accompanied by the formation of macro- as well as micro stresses. The positive and negative effects of macro stresses on the performance of mechanical components are well-known. The impact of micro stresses on damage initiation remains, however, fully unclear. High micro stresses are expected to occur in high-Mn steels due to the thermal expansion mismatch and the differences in mechanical behavior of the phase constituents as well as due to strain-induced phase transformation. Furthermore, the elastic and plastic anisotropy of the austenite associated with texture formation cause inter- and intragranular stresses during forming. This project is part of the collaborative research unit SFB 761 – Steel ab-initio and focuses therefore on understanding the connection between the evolution of phase composition, defect configurations and internal stresses, and the mechanical behavior of high-Mn steels during uni- and multiaxial loadings.

Situação: Concluído; Natureza: Pesquisa.
Integrantes: Haroldo Cavalcanti Pinto – Coordenador / C. Barbatti – Integrante / Lucas Amaral Sales – Integrante.
Financiador(es): Deutsche Forschungsgemeinschaft – Auxílio financeiro.

2005 – 2010 – Texture, Strain and Stress Development in Oxide Scales

Descrição: The integrity and adherence to substrate of protective oxide scales are impaired by stress generation accompanying the growth of oxides on metallic surfaces. Several mechanisms of stress formation during oxide growth have been proposed over the past years. However, none of those processes can solely explain the internal stress situation in most of the naturally growing oxide scales. This project funded by the FWF, Austria, and the MPIE focuses on the particular influence of substrate orientation and preferential orientation of oxide growth on the internal stress state of multiphase oxide scales. To this end, the time evolution of microstructure, internal stresses and their gradients in oxide scales growing on polycrystals and single crystals of pure iron and FeAl-alloys are studied in-situ during oxidation by energy-dispersive XRD with synchrotron radiation and by complementary electron microscopy.

Situação: Concluído; Natureza: Pesquisa.
Alunos envolvidos: Doutorado: (2).
Integrantes: Haroldo Cavalcanti Pinto – Coordenador / Claudia Juricic – Integrante / P. Brito – Integrante.
Financiador(es): Fonds zur Förderung der wissenschaftlichen Forschung – Auxílio financeiro.

2005 – 2008 – Induction Assisted Welding Technologies in Steel Utilization

Descrição: HSLA steel grades are required to reduce weight in industrial machinery. Their mechanical performance is impaired by welding operations which often cause a reduction of toughness and increase the probability for cold cracking due to martensite formation in the fusion zone (FZ) and heat-affected zone (HAZ). Induction heating is capable of directly producing heat inside a work piece. This enables the integration of induction heat-treatments into serial welding processes. In this project, the effect of induction-assisted laser welding on the microstructure and residual stresses of HSLA steel joints was investigated within the framework of the EU-project INDUCWELD funded by the Research Fund for Coal and Steel.

Situação: Concluído; Natureza: Pesquisa.
Integrantes: Haroldo Cavalcanti Pinto – Coordenador / Maria Corpas – Integrante / J. A. Guio – Integrante.
Financiador(es): Research Fund for Coal and Steel – Auxílio financeiro.

2002 – 2005 – Cryogenic Wear of Austenitic Steels

Descrição: The low temperature technology comprises developments in the space technology and applications of superconductivity. Cryogenic temperatures are encountered e.g. in superconducting magnets and magnetic resonance tomographs, where liquid helium (LHe) is employed as cooling agent, and in the aerospace technology, where liquid hydrogen (LH2) became the standard propellant. Hydrogen represents an important alternative to fossil fuels. The liquefied form, at cryogenic temperatures of about 20K, is particularly attractive due to the possibility of stocking a large quantity of hydrogen within a small volume. In moving machine parts cryogenic temperatures and the presence of hydrogen strongly affect the deformation mechanisms and subsequently component failure. Austenitic stainless steels are materials commonly used in cryotechnology. At extremely low temperatures these steels still exhibit good mechanical properties along with sufficient ductility. However, high mechanical loads combined with low temperatures may induce martensitic transfomation. The formation of martensite within the worn surface enhances strength but also causes embrittlement. This could influence the degradation process of cryogenic machine components and disturbs the superconductive effect due to its ferromagnetism. The aim of this project was the investigation of the influence of temperature, environment and loading conditions on the martensitic transformation and the microstructural deterioration of austenitic stainless steels during cryogenic wear. X-ray diffraction and microscopy studies were carried out on samples worn at room temperature in air with different humidities, at 77 K in LN2, at 20 K in LH2 and at 4.2 K in LHe. Results show that martensitic transformation in austenitic steels can be suppressed by increased Ni-contents or its replacement by Mn. It can be shown that strain induced alpha-martensite does not cause a loss of wear resistance at cryogenic temperatures.

Situação: Concluído; Natureza: Pesquisa.
Alunos envolvidos: Graduação: (2) / Doutorado: (1).
Integrantes: Haroldo Cavalcanti Pinto – Integrante / Anke Pyzalla – Coordenador.
Financiador(es): Deutsche Forschungsgemeinschaft – Auxílio financeiro.

Projetos de desenvolvimento

2013 – 2018 – Recobrimento para Anéis de Pistão com durabilidade estendida obtidos através de plasma de elevado impulso (Decisão Dir. 640/2012) (Valor: R$ 3.463.708,00)

Descrição: As tecnologias a serem empregadas nos motores de combustão do futuro, devido às demandas de minimização de emissões poluentes, usam estratégias de minimização da geração dos produtos da combustão (poluentes) de forma a piorar consideravelmente a condição de trabalho dos anéis, seja por uma oferta menor de óleo lubrificante, seja por maiores carregamentos mecânicos, seja por maior carregamento térmico seja por utilização de gases contaminados com partículas abrasivas ou a combinação destas. Portanto, este projeto, tem como objetivo o desenvolvimento de um material cerâmico, com elevada resistência ao desgaste, a ser aplicado como revestimento protetivo em anéis de pistão para motores de combustão interna. Dado o potencial do processo de deposição física em fase de vapor via plasma de elevado impulso (High Power Impulse Magnetron Sputtering – HIPIMS), em termos de nanoestrutura e propriedades das camadas duras, este projeto possui características de inovação de ruptura com elevado potencial tecnológico, pois no meio industrial não se conhece nenhum caso de aplicação ou exploração desta tecnologia no universo da industrial automobilística mundial. Visto que a tecnologia de plasma de elevado impulso apresenta atualmente seu auge no meio acadêmico ou está próximo dele, existe portanto uma lacuna técnica de acesso e domínio do processo de deposição do material cerâmico que permita desenvolver os protótipos de teste e, com isto, o desenvolvimento da sua aplicação e industrialização é praticamente inviável.

Situação: Concluído; Natureza: Desenvolvimento.
Alunos envolvidos: Graduação: (2) / Doutorado: (2).
Integrantes: Haroldo Cavalcanti Pinto – Coordenador / Fernando Alvarez – Integrante / Daniel Wisnivesky – Integrante / Paulo Mordente – Integrante.
Financiador(es): Mahle Metal Leve – Auxílio financeiro / Banco Nacional de Desenvolvimento Econômico e Social – Auxílio financeiro.
Research

2021 – Current – Advanced studies of the microstructure-property relationship of Cr-Al-N mono- and multilayers for the improvement of tribological performance in combustion engines (Proc.: 2019/14262-3) (Budget: R$ 11.160,00 + US$ 48.080,34)

Description: CrN and CrAlN films are widely used in piston rings in order to improve their performance in combustion engines. This extensive application is supported by its good oxidation resistance, high hardness, chemical inertness and wear resistance. The combination of all these properties is highly attractive for applications in the tool, automotive, aerospace and decorative industries. Nowadays, the improvement of the mechanical and thermal properties of monolithically grown CrN coatings can be achieved through solid solution with different elements, such as Al. PVD methods for the deposition of mono- and multi-layers of Cr-Al- N allow to generate a variety of microstructures significant for the mechanical and tribological performance of coating systems. In particular, chemical compositional profiles, particle size distribution, coating architecture, residual/thermal stresses and crystallographic texture allow to optimize the mechanical properties and tribological performance of coatings based on Cr-Al-N. The aim of this project is, therefore, to contribute to the understanding of how specific deposition parameters by DC-MS and HiPIMS determine selected microstructures and mechanical properties with special interest in the performance/tribological response of coatings based on Cr-Al-N. The mono- and multilayers based on Cr-Al-N obtained by the DC-MS and HiPIMS methods will be deposited on stainless steel substrates and compared. Stainless steels are chosen because of their diversity of applications, such as dies, motors and cutting tools. The microstructures produced by distinct PVD routes will be characterized using advanced tools such as GDOES, TKD, EBSD, STEM, FIB-SEM-EBSD tomography and X-ray diffraction (DRX) with synchrotron light. To evaluate the mechanical and tribological properties, stress analyzes will be performed using XRD and wear and friction tests with the sphere-on-disk configuration will be conducted at room temperature and elevated temperatures, as well as in erosive-corrosive environments.

Status: In progress; Nature: Research.
Students involved: Doctorate: (2).
Members: Haroldo Cavalcanti Pinto – Coordinator / Christian Greiner – Member.
Financer(s): São Paulo Research Foundation – Scholarship.

2018 – 2019 – Thermomechanical processing of emerging metallic materials (Proc.: PROBRAL 88881.143948/2017-01) (Budget: R$ 200,000.00)

Description: Advanced high strength (AHS) steels, magnesium and titanium alloys are used for structural elements in transportation and sporting goods. Their advantages are high specific stiffness and strength, particularly under bending loads, assets that go along with the industrial efforts of weight reduction and low emissions. Austenitic stainless steels have a wide range of applications of their high temperature strength caused by the precipitation of second-phase, along with resistance to carburizing, corrosion and oxidation in different environments. The capability of multiphase alloys to withstand external loads is determined by the mechanical and physical properties of the microstructural components, their thermal/mechanical stability and their geometrical arrangement. All these parameters vary during production and service. Therefore, physical aspects such as nucleation and growth of phases, grain re-orientation, phase-specific stresses, diffusion controlled morphological changes or bonding of interfaces must be considered to understand the thermomechanical behavior of the alloys. Furthermore, microstructural features influence the stress partition between phases, stress localization as well as possible damage nucleation and evolution. The sensitivity of the mechanical properties to microstructural changes in structural steels, magnesium and titanium alloys has been studied and reported but new insights can be gained nowadays due to the advance of modern characterization methods that allow to observe the evolution of the microstructure in-situ and /or three-dimensionally. In order to improve the mechanical properties of such alloys, hot forming processes have been studied for grain refinement. They promote microstructural modification due to dynamic recrystallization and texture evolution. Besides this, the thermomechanical effect during hot stamping, in which the tool is cooled during the step, is another aspect that must be taken into account since this has been largely used and studied mainly in the automotive industries. This project concentrates on the investigation of the formation and evolution of 3D multiphase arrangements, phase-specific texture and stresses in selected Nb-microalloyed steels, magnesium and titanium alloys during thermomechanical treatments, thus aiming at controlling their microstructure and thermomechanical response. This requires the use of computational thermodynamics to pre-screen potential alloying elements for iron systems, advanced 3D high-resolution imaging methods to reveal the architecture of the alloys and in-situ synchrotron X-ray diffraction combined with a Gleeble simulator at the XTMS beamline of LNLS to follow the formation and evolution of microstructural phases as well as their specific preferential grain orientations and stresses during different thermomechanical processes.

Status: Completed; Nature: Research.
Students involved: Doctorate: (6).
Members: Haroldo Cavalcanti Pinto – Coordinator / Rodrigo S. Coelho – Member / Soldera, Flavio – Member / Mücklich, Frank – Member / Pedro Paiva Brito – Member.
Financer(s): CAPES – Bilateral Cooperation.

2017 – 2020 – Structural and tribological properties of ceramic mono- and multilayers containing Cr and Al obtained by the High-Power Impulse Magnetron Sputtering process (Proc.: 409545/2016-3) (Budget: R$ 43,000.00)

Description: The objective of this project is the development of overlay layers based on CrN and Cr(1-X)AlXN to be deposited on nitrided martensitic 440 stainless steel substrates using the HiPIMS (High Power Impulse Magnetron Sputtering) deposition process. The substrates were supplied by the company MAHLE Metal Leve, interested in this development. The challenge in establishing the HiPIMS process is related to its greater complexity, which is due to the greater number of parameters involved, compared to the commercial process of vaporization by cathodic arc. While in cathodic arc vaporization the deposition is mainly determined by the discharge current, the HiPIMS technology requires the optimization of the pulsation form of the power source. This includes adjusting the setting of polarization (ton) and depolarization (toff) times of the targets, as well as the peak current for each average power applied to the target, in addition to parameters common to physical deposition processes, such as partial pressures of gas in the reactor, temperature and negative polarization (bias) of the substrate. The HiPIMS physical deposition method makes it possible to obtain compounds with high purity and structural control, both at the atomic level and at the nanometric scale. Precise adjustment of process parameters allows the deposition of monolayers, multilayers, nanocomposites, functionalized nanostructures and particles for various applications. Currently, transition metal nitrides have been extensively studied for applications that require resistance to friction, wear, corrosion and oxidation. Among these compounds, chromium nitride (CrN) stands out for having great technological importance. Its mechanical and tribological properties and its relative ease of deposition make this material unique for many uses, such as hard coatings and, more recently, medical implants. The research proposed in this project consists in the development of the HiPIMS process for the deposition of CrN and Cr(1-X)AlXN films, in addition to multilayers of CrN/Cr(1-X)AlXN with superstructure in order to obtain hard and nanostructured coatings with high interfacial area and good toughness , using metallic targets of Cr and CrAl alloys (50-50, 30-70, 70-30%at), in addition to gaseous mixtures of nitrogen and argon as precursors for the coatings. The layers obtained will be characterized by a combination of several techniques, such as X-Ray Diffraction, SEM-EDS-EBSD, MET, AFM, XPS, optical profilometry, instrumented nanohardness and scratch and wear tests, from which it will be possible correlate the mechanical and tribological properties with the micro and nano structure of the deposited coating.

Status: Completed; Nature: Research.
Students involved: Graduation: (2) / Academic Master: (1) / Doctorate: (1).
Members: Haroldo Cavalcanti Pinto – Coordinator / Fernando Alvarez – Member / Alisson Mendes Rodrigues – Member / Viviane Oliveira Soares – Member.
Financier(s): National Council for Scientific and Technological Development – Financial aid.

2015 – 2019 – CREATe-Network: Processing and Characterization of Advanced Composites for Resource-Efficient Applications and Technologies

Description: CREATe-Net is composed of 3 academic institutions in Europe (Saarland Univ., DE; Technical Univ. of Catalonia, ES; and INM – Leibniz Institute for New Materials, DE), 3 non-academic institutions in Europe (AB Sandvik Coromant, SE; Steinbeis Research and Innovation Centers, DE; and Nanoforce Ltd., UK), as well as 6 academic partners outside Europe (CSIR – Council for Scientific and Industrial Research, ZA; Catholic University of Uruguay, UY; Instituto de Investigaciones en Ciencia e Ingeniería de Materiales, AR; Univ. de Concepción, CL; Univ. de Sao Paulo, BR; and Georgia Institute of Technology, US). The network will cooperate in the field of design, processing and characterization of novel composite materials for resource-efficient applications and environmentally friendly technologies, in particular energy storage, bearings, electrical contacts, and cutting tools. The purpose of the network is to combine different thematic expertise of the academic and industrial network members in the multidisciplinary field of science and engineering materials in order to design new composite materials with superior properties and performance. The expertise of the network includes: a) design by modeling at different scales (eg atomistic modelling, thermodynamic and kinetic modelling, finite element modelling); b) novel processing methods (eg atomic layer deposition, severe plastic deformation and rapid solidification); c) advanced characterization methods (eg serial sectioning and atom probe tomography, high resolution transmission electron microscopy); d) processing/characterization of carbon materials, metal and ceramic matrix composites as well as functionally graded materials; and e) performance testing for targeted applications (available through special designed testing facilities at the research centers and industrial partners). Two workshops and one final conference will contribute to the exchange of knowledge besides the exchange of researchers.

Status: Completed; Nature: Research.
Members: Haroldo Cavalcanti Pinto – Member / F. Mücklich – Coordinator / Soldera, Flavio – Member / José García – Member.

2014 – 2017 – Microstructural engineering of structural light alloys (Proc.: 407399/2013-5) (Budget: R$ 140,800.00)

Description: The proposed project concentrates on the investigation of the formation and evolution of three-dimensional multiphase arrangements of selected structural aluminum, magnesium and titanium alloys during thermal and/or thermo-mechanical treatments aiming at controlling their microstructure and, consequently, their thermo- mechanical behavior. This will require the use of state-of-the-art ex situ and in situ 3D imaging methods to reveal the internal architecture of the alloys together with in situ bulk diffraction methods to follow the formation and evolution of microstructural phases as well as their evolution and load carrying capability during different loading conditions.

Status: Completed; Nature: Research.
Members: Haroldo Cavalcanti Pinto – Coordinator / Guillermo Carlos Requena – Member.
Financer(s): National Council for Scientific and Technological Development – Cooperation

2011 – Current – Support Center for Research in Advanced Materials (NAP-MA) at USP (Budget: R$ 900,000.00)

Description: The mission of the NAP-MA is to create an inter and multidisciplinary environment and intense collaboration of research, development and innovation in hybrid materials, adding competences in the areas of ceramic materials (polycrystalline and vitreous), metals, polymers and composites existing in the SMM /EESC/USP, plus the patent capacity of this department in mechanical and tribological tests, and also the competence in the study of physics and chemistry of condensed matter from the IFSC/USP’s Crystals and Ceramic Materials Growth Group, for the study and development of materials involving their interrelationships, both in the processing stage and in the generation of hybrid materials themselves, with superior properties.

Status: In progress; Nature: Research.
Members: Haroldo Cavalcanti Pinto – Member / Antônio Carlos Hernandes – Coordinator / Antônio José Felix de Carvalho – Member / Vera Lúcia Arantes – Member / Rafael Salomão – Member / Marcelo A. Chinelatto – Member / Márcia Cristina Branciforti – Member / Eduardo Bellini Ferreira – Integral.
Financier(s): Universidade de São Paulo – Financial aid.

2011 – 2015 – Friction Joint and Mechanical Mixing in High Performance Thixoformed Magnesium Alloys (Proc.: 2010/11391-2) (Budget: R$168,648.20 + US$232,322.17)

Description: This project aims to study the friction and mechanical mixing (SFMM) weldability of new lightweight and recyclable materials with high performance based on ZK60 magnesium alloy (Mg-6%Zn-1%Zr) modified with different contents of mischmetal (ZK60-RE): 0.5, 1.5 and 2.5 % by weight. To obtain such materials still unexplored in Brazil, the use of semi-solid casting under mechanical agitation is proposed, combined with thermal treatments of the type T4, T5 or T6. The ZK60 alloy represents an important matrix for the development of materials with applications in lighter aeronautical structures, as it offers the greatest specific mechanical strength among traditional magnesium alloys, approaching the 7075 aluminum alloy. Its modification through addition of rare earths aims to form intermetallics with high melting point and thermochemical stability necessary to increase mechanical strength at room temperature and also at higher temperatures; in addition to resistance to corrosion and oxidation. On the other hand, zirconium acts in the refining of grain in magnesium castings, increasing the potential of these materials for a definitive molding through the casting of semi-solids. The influence of casting, heat treatment and joining parameters will be quantified on the microstructure, mechanical properties, behavior in corrosive media and oxidation of alloys and their welded joints by friction and mechanical mixing.

Status: Completed; Nature: Research.
Students involved: Graduation: (3) / Doctorate: (1).
Members: Haroldo Cavalcanti Pinto – Coordinator / Antonio J. Ramirez – Member / Ricardo Henrique Buzolin – Member / Erenilton Pereira da Silva – Member / Larissa Fernandes Batista – Member / Bruna Callegari – Member.
Financer(s): São Paulo Research Foundation – Financial aid.

2010 – 2013 – NanoCom-Network: Advanced Processing and Characterization of Micro and Nano Composites (Budget: US$ 32,000.00)

Description: Advanced materials consisting of many constituents such as metal matrix composites, cellular materials, graded materials and eutectic alloys are continuously improved in order to tailor their properties and comply with specific application requirements. These materials are finding more and more technological applications where high performance of materials is required and especially when light weight is an important factor. Composite materials offer unique mechanical and physical properties as a result of the interaction between their constituents but primarily by their geometrical arrangement, ie internal architecture. A 3D approach is absolutely necessary to understand how the architectural features influence the physical behavior of heterogeneous materials. Furthermore, if the 3D resulting from the combination of constituent material is known, this information can be capitalized to design new heterogeneous materials with tailored and high performance properties. In the present project, different processing techniques will be used and further developed. Furthermore, new characterization techniques in all length scales such as FIB-tomography, atom probe tomography, synchrotron tomography and synchrotron XRD will be optimized for the special use in the characterization of composites. Within the broad field of composite materials in the micro as well as in the nano scale, we will concentrate on the following systems and aspects: 1) Advanced design of highly functionalised carbon nanotubes (CNT) reinforced composites; 2) Advanced design of Al-MMC and effects of interfaces; 3) Advanced production and characterization of nano-structured bulk metal-ceramic composites; 4) Advanced production and characterization of nano-structured coatings; 5) MMCs reinforced with diamond particles; 6) Modern and 3D characterisation of MMC.

Status: Completed; Nature: Research.
Students involved: Doctorate: (1).
Members: Haroldo Cavalcanti Pinto – Coordinator / J. Garcia – Member / Waldek Bose Filho – Member / Luiz Carlos Casteletti – Member / José Ricardo Tarpani – Member / Marcelo Falcão – Member / Augusta Isaac Neta Pinto – Member.
Financier(s): European Union – FP7 Program – Financial aid.

2010 – 2012 – Obtaining and characterization of dissimilar joints by friction and mechanical mixing between TWIP and ARBL automotive steels (Proc.: 474718/2010-7) (Budget: R$ 40,395.00)

Description: This is a technological project to study the weldability of new austenitic high Mn steels with Maclation Induced Plasticity Effect (TWIP) with microalloyed high strength low alloy steels (ARBL) by friction technology and mechanical mixing (Friction Stir Welding). Despite bringing together extraordinary mechanical strength and large elongations, TWIP steels pose challenges to conventional fusion welding processes when considered for the production of custom welded lightweight vehicle structures. This is due to its austenitic microstructure and its high content of alloying elements, which favor the formation of fragile phases in the melting zone, as well as high residual stresses in the weld bead and in the thermally affected areas, during union with commercial low-alloy and predominantly ferritic steels. Considering that TWIP steels are not yet commercially available, two types of TWIP steel will be produced on a laboratory scale using chemical compositions already well established in the international scientific literature. The processing route will be the one traditionally used for austenitic stainless steels and also documented in the literature for TWIP steels, ie casting followed by homogenization and hot mechanical forming by forging. ARBL steels, to be used in the production of dissimilar joints, will be two commercial alloys for cold forming supplied by ThyssenKrupp Aceros y Servicios SA. The welded joints will be produced with two distinct thermal inputs, varying the tool rotation speed. The impact of heat input on friction welding and mechanical mixing (SFMM) of TWIP steels with ARBL steels will be evaluated in relation to the mechanical properties of the joints, their microstructural gradients, the morphological aspects of their fracture surfaces, as well as with respect to the state of residual stresses.

Status: Completed; Nature: Research.
Students involved: Graduation: (1) / Academic Masters: (2).
Members: Haroldo Cavalcanti Pinto – Coordinator / Antonio J. Ramirez – Member / Omar Maluf – Member.
Financier(s): National Council for Scientific and Technological Development – Financial aid.
Number of C, T & A productions: 3

2008 – 2011 – Wear Protecting Nanostructured Coatings for Cutting Processes

Description: The productivity as well as the lifetime of cutting tools can be considerably increased by combining suitable technologies to modify the surface of the substrate prior to coating coupled with new multiphase nanostructured coatings. This project is a DFG research grant for German-Brazilian cooperation aiming at understanding the mechanisms of wear, corrosion, phase transformations and damage initiation in novel wear protecting nanocoatings. At MPIE Dr. J. Garcia will guide the production of coatings with tailored microstructures (graded, multilayer and composite) by thermodynamic simulations and cutting tests. Dr. H. Pinto will be responsible for the microstructure and residual stress assessment in the coated tools. The Brazilian partners will pre-treat the substrates by noble gas bombardment (UNICAMP) and characterize the resulting microstructures and residual stresses of the modified substrates (Brazilian Synchrotron Light Laboratory, LNLS).

Status: Completed; Nature: Research.
Members: Haroldo Cavalcanti Pinto – Coordinator / J. Garcia – Member / Roosevelt Droppa Jr. – Member / Fernando Alvarez – Member.
Financier(s): Deutsche Forschungsgemeinschaft – Financial aid.

2007 – 2009 – Defects and Internal Stresses in Novel Austenitic high-Mn Steels

Description: The deformation behavior (TRIP/TWIP) of the austenitic high-Mn steels is influenced by the steel composition and the temperature which change the stacking fault energy (SFE) of the austenitic lattice. In addition to the SFE, the level of deformation and the multiaxiality of the stress state also affect the deformation mechanisms of the austenite. On the other hand, the manufacturing and service of mechanical components from high-Mn steels are accompanied by the formation of macro- as well as micro stresses. The positive and negative effects of macro stresses on the performance of mechanical components are well-known. The impact of micro stresses on damage initiation remains, however, fully unclear. High micro stresses are expected to occur in high-Mn steels due to thermal expansion mismatch and the differences in mechanical behavior of the phase constituents as well as due to strain-induced phase transformation. Furthermore, the elastic and plastic anisotropy of the austenite associated with texture formation cause inter- and intragranular stresses during forming. This project is part of the collaborative research unit SFB 761 – Steel ab-initial and focuses on understanding the connection between the evolution of phase composition, defect configurations and internal stresses, and the mechanical behavior of high-Mn steels during uni- and multiaxial loadings.

Status: Completed; Nature: Research.
Members: Haroldo Cavalcanti Pinto – Coordinator / C. Barbatti – Member / Lucas Amaral Sales – Member.
Financier(s): Deutsche Forschungsgemeinschaft – Financial aid.

2005 – 2010 – Texture, Strain and Stress Development in Oxide Scales

Description: The integrity and adherence to substrate of protective oxide scales are impaired by stress generation accompanying the growth of oxides on metallic surfaces. Several mechanisms of stress formation during oxide growth have been proposed over the past years. However, none of those processes can only explain the internal stress situation in most of the naturally growing oxide scales. This project funded by the FWF, Austria, and the MPIE focuses on the particular influence of substrate orientation and preferential orientation of oxide growth on the internal stress state of multiphase oxide scales. To this end, the time evolution of microstructure, internal stresses and their gradients in oxide scales growing on polycrystals and single crystals of pure iron and FeAl-alloys are studied in-situ during oxidation by energy-dispersive XRD with synchrotron radiation and by electron microscopy.

Status: Completed; Nature: Research.

Students involved: Doctorate: (2).

Members: Haroldo Cavalcanti Pinto – Coordinator / Claudia Juricic – Member / P. Brito – Member.
Financer(s): Fonds zur Förderung der wissenschaftlichen Forschung – Financial aid.

2005 – 2008 – Induction Assisted Welding Technologies in Steel Utilization

Description: HSLA steel grades are required to reduce weight in industrial machinery. Their mechanical performance is impaired by welding operations which often cause a reduction of toughness and an increase in the probability of cold cracking due to martensite formation in the fusion zone (FZ) and heat-affected zone (HAZ). Induction heating is capable of directly producing heat inside a work piece. This enables the integration of induction heat-treatments into serial welding processes. In this project, the effect of induction-assisted laser welding on the microstructure and residual stresses of HSLA steel joints was investigated within the framework of the EU-project INDUCWELD funded by the Research Fund for Coal and Steel.

Status: Completed; Nature: Research.
Members: Haroldo Cavalcanti Pinto – Coordinator / Maria Corpas – Member / JA Guio – Member.
Financier(s): Research Fund for Coal and Steel – Financial aid.

2002 – 2005 – Cryogenic Wear of Austenitic Steels

Description: The low temperature technology comprises developments in the space technology and applications of superconductivity. Cryogenic temperatures are encountered eg in superconducting magnets and magnetic resonance tomographs, where liquid helium (LHe) is employed as cooling agent, and in the aerospace technology, where liquid hydrogen (LH2) became the standard propellant. Hydrogen represents an important alternative to fossil fuels. The liquefied form, at cryogenic temperatures of about 20K, is particularly attractive due to the possibility of stocking a large quantity of hydrogen within a small volume. In moving machine parts cryogenic temperatures and the presence of hydrogen strongly affect the deformation mechanisms and subsequent component failure. Austenitic stainless steels are commonly used in cryotechnology. At extremely low temperatures these steels still exhibit good mechanical properties along with sufficient ductility. However, high mechanical loads combined with low temperatures may induce martensitic transfomation. The formation of martensite within the worn surface enhances strength but also causes embrittlement. This could influence the degradation process of cryogenic machine components and disturbs the superconductive effect due to its ferromagnetism. The aim of this project was the investigation of the influence of temperature, environment and loading conditions on the martensitic transformation and the microstructural deterioration of austenitic stainless steels during cryogenic wear. X-ray diffraction and microscopy studies were carried out on samples worn at room temperature in air with different humidities, at 77 K in LN2, at 20 K in LH2 and at 4.2 K in LHe. Results show that martensitic transformation in austenitic steels can be suppressed by increased Ni-contents or its replacement by Mn. It can be shown that strain induced alpha-martensite does not cause a loss of wear resistance at cryogenic temperatures.

Status: Completed; Nature: Research.
Students involved: Graduation: (2) / Doctorate: (1).
Members: Haroldo Cavalcanti Pinto – Member / Anke Pyzalla – Coordinator.
Financier(s): Deutsche Forschungsgemeinschaft – Financial aid.

Development projects

2013 – 2018 – Coating for Piston Rings with extended durability obtained through high impulse plasma (Decision Dir. 640/2012) (Budget: R$ 3,463,708.00)

Description: The technologies to be used in the combustion engines of the future, due to the demands to minimize pollutant emissions, use strategies to minimize the generation of combustion products (pollutants) in order to considerably worsen the working condition of the rings, either by a smaller supply of lubricating oil, either due to greater mechanical loading, or due to greater thermal loading, or the use of gases contaminated with abrasive particles, or a combination of these. Therefore, this project aims to develop a ceramic material, with high wear resistance, to be applied as a protective coating on piston rings for internal combustion engines. Given the potential of the physical vapor deposition process via high impulse plasma (High Power Impulse Magnetron Sputtering – HIPIMS), in terms of nanostructure and hard layer properties, this project has innovative breakthrough characteristics with high technological potential, because in the industrial environment there is no known case of application or exploitation of this technology in the world of the automobile industry worldwide. Since high-pulse plasma technology is currently at its peak in academia or is close to it, there is therefore a technical gap in accessing and mastering the ceramic material deposition process that allows the development of test prototypes and, with this, the development of its application and industrialization is practically unfeasible.

Status: Completed; Nature: Development.
Students involved: Graduation: (2) / Doctorate: (2).
Members: Haroldo Cavalcanti Pinto – Coordinator / Fernando Alvarez – Member / Daniel Wisnivesky – Member / Paulo Mordente – Member.
Financier(s): Mahle Metal Leve – Financial aid / National Bank for Economic and Social Development – Financial aid.