- Prof. Dr. Haroldo Cavalcanti Pinto
Universidade de São Paulo - Campus 2
Escola de Engenharia de São Carlos
Departamento de Engenharia de Materiais
Avenida João Dagnone 1100
CEP 13563-120 - São Carlos/SP - Brazil - +4915205902463
Haroldo C . Pinto
USP, Departamento de Engenharia de Materiais (SMM), Faculty Member
- Surface treatment, Steel, Nano Technology, X ray diffraction, Synchrotron Radiation Techniques, Neutron Diffraction, and 17 morePVD Magnetron Sputtering, PVD, CVD, ALD, Plasma Engineering, Magnesium Alloys, Welding Metallurgy, Friction Stir Welding, Additive Manufacturing, Biomaterials and Corrosion, Oxidation, Mechanical Behavior Of Materials, Physical Metallurgy, Residual Stress (Engineering), Titanium alloys, Tribology, Hydrogen Storage, Hydrogen Storage Materials, and Hydrogen Energyedit
- Graduated (2001) and Ph.D. (2005) in Metallurgical and Materials Engineering at the Technische Universität Berlin, Ge... moreGraduated (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 an Associate Professor in 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 the 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. 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.edit
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The microstructure and mechanical properties of dissimilar butt-joints of high-strength low-alloy steel to austenitic high Mn TRIP steels produced by manual TIG welding with AISI 309L filler metal were investigated. The heat input was... more
The microstructure and mechanical properties of dissimilar butt-joints of high-strength low-alloy steel to austenitic high Mn TRIP steels produced by manual TIG welding with AISI 309L filler metal were investigated. The heat input was varied by changing the welding current between 40 and 70 A. A fully austenitic microstructure with nearly equiaxed grains and without any iron/manganese carbide is observed in the high Mn TRIP base metal, whereas polygonal ferrite and pearlite colonies oriented along the rolling direction are found in the high-strength low-alloy steel base metal. Coarse and refined heat-affected zones (HAZ) were observed in the high-strength low-alloy steel, whereas no significant HAZ was detected at the TRIP side. Bainite and/or martensite grew in the coarse HAZ of the high-strength low-alloy steel steel joined with highest current. The weld seam was formed by austenitic dendrites with interdendritic ferrite and martensite. The best welding condition was achieved with an intermediate current of 50 A, where the hardness transition was smooth, fracture occurred in the HSLA base metal and the joint ductility was higher.
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Research Interests: Materials Engineering, Mechanical Engineering, Materials Science, Microstructure, Electron Microscopy, and 15 moreElectron Backscatter Diffraction (EBSD), Metallurgy, Laser Welding, Magnesium, Welding, Mechanical Testing, X ray diffraction, Microstructures, Residual Stress, Deformation Mechanism, Tensile Test, Magnesium Alloy, Heat affected zone, Ultimate Tensile Strength, and Mechanical Property
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The evolution of internal stresses in oxide scales growing on an Fe3Al polycrystal in atmospheric air at 700 determined using in-situ energy-dispersive synchrotron x-ray diffraction. Texture analyses were performed ex-situ after 5h of... more
The evolution of internal stresses in oxide scales growing on an Fe3Al polycrystal in atmospheric air at 700 determined using in-situ energy-dispersive synchrotron x-ray diffraction. Texture analyses were performed ex-situ after 5h of oxidation at 700 the oxide scale thickness, as determined by x-ray photoelectron spectroscopy, lays between 80 and 100nm. The main phase present in the oxide scales is -Al2O3, with minor quantities of metastable -Al2O3 detected in the first minutes of oxidation, as well as -Fe2O3. -Al2O3 grows with a weak (0001) fiber texture in the normal direction. During the initial stages of oxidation the scale develops increasing levels of compressive stresses, which later evolve to a steady state condition situated around -300MPa.
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The size change of a low carbon maraging steel and of a ledeburitic cold work tool steel produced by ingot (IN) or powder metallurgy (PM) was measured by dilatometry using specimens taken in longitudinal or transverse direction of hot... more
The size change of a low carbon maraging steel and of a ledeburitic cold work tool steel produced by ingot (IN) or powder metallurgy (PM) was measured by dilatometry using specimens taken in longitudinal or transverse direction of hot working. The anisotropy of the size change during martensitic transformation ΔεM was negative for the maraging and the PM steel, but positive for the IN steel and the more so, if the cooling rate was raised by injecting liquid nitrogen during quenching to −150 °C. The microstructure and texture was investigated by high resolution SEM equipped with microprobe analysis and respective imaging as well as by EBSD. The results show that Δεis not related to a texture M of the martensitic matrix but to a microstructural banding caused by microsegregation and hot working. The alignment of the eutectic M7 C3 carbides in the direction of hot working coincides with their texture.
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With the aim of investigating a laser-welded dissimilar joint of TWIP and TRIP steel sheets, the microstructure was characterized by means of OM, SEM, and EBSD to differentiate the fusion zone, heat-affected zone, and the base material.... more
With the aim of investigating a laser-welded dissimilar joint of TWIP and TRIP steel sheets, the microstructure was characterized by means of OM, SEM, and EBSD to differentiate the fusion zone, heat-affected zone, and the base material. OIM was used to differentiate between ferritic, bainitic, and martensitic structures. Compositions were measured by means of optical emission spectrometry and EDX to
Research Interests: Materials Engineering, Mechanical Engineering, Materials Science, Microstructure, Electron Backscatter Diffraction (EBSD), and 13 moreMetallurgy, Manganese, Laser Welding, Welding, Microstructures, Residual Stress, TRIP steel, Martensite, Martensitic Stainless Steel, Tensile Test, Heat affected zone, Ultimate Tensile Strength, and Mechanical Property
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The low carbon martensitic stainless AWS 410NiMo steel has in its chemical composition 13% chromium, 4% nickel, and 0.4% molybdenum (wt.%) and is used in turbine recovery, rotors, and high-pressure steam pump housings due to its... more
The low carbon martensitic stainless AWS 410NiMo steel has in its chemical composition 13% chromium, 4% nickel, and 0.4% molybdenum (wt.%) and is used in turbine recovery, rotors, and high-pressure steam pump housings due to its resistance to impact at low temperatures, as well as to corrosion and cavitation. Those applications of the AWS 410NiMo steel frequently demand repair, which is performed by welding or cladding. Arc welding is a well-established technique for joining materials and presents several parameters that influence the mechanical performance of the weld bead. Although numerous welding processes exist, optimizing welding parameters for specific applications and materials is always challenging. The present work deals with a systematic study to verify the correlation between the pulsed fluxed core arc welding (FCAW) parameters, namely pulse current and frequency, welding speed, and contact tip work distance (CTWD), and the bead morphology, microstructure formation, resi...
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A hybrid magnetron sputtering process (dcMS/HiPIMS) was developed to manufacture nanostructured CrN/Cr1-xAlxN multilayers, motivated by improving the low-emission efficiency when applied on gas-nitrided diesel piston rings of a... more
A hybrid magnetron sputtering process (dcMS/HiPIMS) was developed to manufacture nanostructured CrN/Cr1-xAlxN multilayers, motivated by improving the low-emission efficiency when applied on gas-nitrided diesel piston rings of a next-generation of combustion engines. In order to improve the mechanical, tribological, and corrosion behavior of the multilayers, the hybrid dcMS/HiPIMS process was designed by selecting the optimal sputtering procedure applied to AISI 440 base steel. The effect of substrate bias and carousel rotational speed on the phase composition, crystallographic texture, residual stresses, surface roughness, coating periodicity and densification, instrumented hardness, elastic modulus, as well as wear and corrosion resistance was determined. The results have demonstrated that hybrid magnetron sputtering produces multilayers with a superlattice structure, which outperforms commercial PVD coatings of CrN for diesel piston rings manufactured by cathodic arc evaporation. ...
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Pb-Co anodes have been considered an attractive candidate for oxygen evolution reaction (OER) applications due to their low overpotential to catalyze the OER and its low cost. Despite these characteristics, their efficiency to produce... more
Pb-Co anodes have been considered an attractive candidate for oxygen evolution reaction (OER) applications due to their low overpotential to catalyze the OER and its low cost. Despite these characteristics, their efficiency to produce oxygen at high current densities is low. In this work, we report a Pb-Co-Sn film with enhanced efficiency and improved electrocatalytic properties. Pulsed cathodic electrodeposition was used to develop Pb-Co-Sn films at different deposition times among 2 and 10 min. Polarization curves were recorded to determine the deposition parameters. Morphological studies showed that the films grown for 6 min exhibited a well-covered and homogeneous surface. Structural analyses were recorded employing X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) that showed a nanostructured film composed by Pb and CoSn2 nanocrystallites. The electrochemical behavior of the developed Pb-Co-Sn films was measured by polarization curves in a sulfuric acid solution demonstrating a great ability to catalyze the OER: a reduction of the overpotential by 55% and 8.5% versus a Pb-Ca-Sn anode and Pb-Co film, respectively, accompanied by a strong increase in the current density. Thus, the addition of tin to the anode has a positive effect on the electrocatalytic performance of the film.
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The aim of the present work is to explore the age-hardening potential of Ti-6Al-4V (Ti-64) alloy with variation of the starting microstructure, with attention to the precipitation of nano-sized Ti3Al phase, as influenced by... more
The aim of the present work is to explore the age-hardening potential of Ti-6Al-4V (Ti-64) alloy with variation of the starting microstructure, with attention to the precipitation of nano-sized Ti3Al phase, as influenced by microstructural features. The alloy was either solution-treated or deformed by compression at temperatures above and below its β-transus to produce microstructures comprising martensitic, lamellar and globular α morphologies, as well as the existence or absence of β phase, and subsequently submitted to ageing treatments at 400°C/8h using in situ x-ray diffraction. Precipitated fractions of Ti3Al were obtained via Rietveld refinement and aged microstructures were characterized by micro-hardness measurements. Results show that α2 precipitation is favored by a globular morphology of α and hindered by a martensitic α morphology, and suggest that the presence of β phase also has as influence on precipitation.
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As-cast ZK40 alloys, modified with the addition of CaO, Gd, Nd and Y were investigated. Solution heat treatments were performed based on differential thermal analysis results. The unmodified ZK40 alloy exhibited microstructure with nearly... more
As-cast ZK40 alloys, modified with the addition of CaO, Gd, Nd and Y were investigated. Solution heat treatments were performed based on differential thermal analysis results. The unmodified ZK40 alloy exhibited microstructure with nearly no intermetallic compound but with precipitates formed during the solution treatment. The modified ZK40 alloys exhibited a semi-dissolved network of intermetallic compounds along the grain boundaries and zones of intermetallic compounds within the grains. Interestingly, no precipitates were observed immediately next to the grain boundaries. The energy dispersive X-ray spectroscopy line scans showed an enrichment of Zn and Zr in the regions where the precipitates are found, suggesting that they are Zn-Zr precipitates. The ageing behaviour was compared between the as-cast and the solution treated materials and it was found that apart from the ZK40-Gd, ZK40-Nd and ZK40-Y aged at 200 °C after solution treatment, there is no notable ageing response for ...