Alberto Moreira Jorge Junior

• Full Professor
• Professor (Full) at Federal University of São Carlos

The present study investigated structural phase transitions in heat-treated mechanical alloyed Al65Cu20Fe15ÿxCrx (x = 2.5, 5, and 10). The Al, Cu, Fe, and Cr powder mixtures were mechanically alloyed by using a planetary ball mill for 30, 60, and 120 minutes. After 120 minutes of milling, Al65Cu20Fe12.5Cr2.5 and Al65Cu20Fe5Cr10 alloys showed b-AlFe...

Ultrafine-grained and heterostructured materials are currently of high interest due to their superior mechanical and functional properties. Severe plastic deformation (SPD) is one of the most effective methods to produce such materials with unique microstructure-property relationships. In this review paper, after summarizing the recent progress in...

The application of amorphous alloys as thin-film coatings with good corrosion properties has drawn attention in the last years since overcoming the typical limitations of these materials, such as the critical size and brittleness. Techniques based on Physical Vapor Deposition, like DC magnetron sputtering, are interesting once it allows parameter o...

In this study, we successfully obtained a 2Mg-Fe mixture through mechanical alloying (MA) and processed it via accumulative roll bonding (ARB) (MA+ARB). Our primary focus was to analyze the impact of ambient air exposure while also evaluating the processing route. Some powder samples were exposed to air for 12 months (stored in a glass desiccator w...

The Fe66Cr10Nb5B19 alloy coatings with high hardness (~850 HV300), low porosity (less 3%), low content of crystalline phase (less 2.5 wt%), and high wear resistance were obtained in a wide range of detonation spraying modes. The results of comparative dry linearly reciprocating sliding wear tests of the obtained coatings and stainless steel carried...

The influence of devitrification on microstructure, corrosion, and mechanical properties of two new FeCrMoNbB and FeCrMoNiB pseudo-high entropy (PHE) amorphous alloys have been investigated to be used as coatings. Amorphous ribbons produced by melt spinning were heat-treated to simulate crystallization. Amounts of amorphous phases were kept at high...

In this study, we successfully obtained a 2Mg-Fe mixture through mechanical alloying (MA) and processed it via accumulative roll bonding (ARB) (MA+ARB). Our primary focus was to analyze the impact of ambient air exposure while also evaluating the processing route. Some powder samples were exposed to air for 12 months before undergoing ARB processin...

The microstructural features and mechanical properties of composites formed by spark plasma sintering (SPS) of Al + 20 vol.% Fe and Al + 20 vol.% Fe66Cr10Nb5B19 (glassy alloy) mixtures composed of micrometer-sized particles are presented. The interaction between the mixture components was studied by differential thermal analysis and through examini...

Due to their unique properties, titanium (Ti) and Ti-alloys are particularly suitable for biomedical devices. Ti has a high specific strength and low Young’s modulus (reducing stress shielding), high corrosion resistance, and superior biocompatibility. However, Ti’s moderately low Young’s modulus (100–110 GPa) is still considerably higher than to b...

Elemental powder mixtures of Al, Cu, and Fe with nominal composition of Al65Cu20Cu15 were proceeded in a planetary ball mill for up to 5 h. Phase analysis of as-milled powders shows that only diffraction peaks of metallic elements were detected after milling for 60 min. The long milling times resulted in formation of an Al (Cu, Fe) solid solution (...

Metallic-glass-reinforced metal matrix composites are a novel class of composite materials, in which particles of alloys with an amorphous structure play the role of reinforcement. During the fabrication of these composites, a crystalline metal is in contact with a multicomponent alloy of an amorphous structure. In the present work, the morphologic...

The corrosion behaviour of laser and plasma nitrided β-Ti12Mo6Zr2Fe biomaterial was evaluated. Polarization curves and electrochemical impedance spectroscopy were performed in simulated body fluid (SBF) at 37 oC. Both treatments formed titanium-nitride at the alloy’s surface, and significantly improved the corrosion performance of the alloy. At ano...

Titanium alloys, particularly the β-Ti12Mo6Zr2Fe (TMZF), have received significant attention in orthopedic applications due to their mechanical properties and biocompatibility. However, the poor osteointegration of Ti alloys has limited their orthopedic applications, but it can be improved by adding a bioactive layer. In the present study, the dip-...

The Ti21Nb24Mo23Hf17Ta15 biocompatible high entropy alloy (HEA) was analyzed for different air-exposure times before corrosion tests in simulated body fluid (SBF), simulating implant air storage before implantation, presenting tremendous surface passivation capacity. Electrochemical impedance spectroscopy indicates layers thickening during air expo...

This study evaluated the surface optimization of β-Ti-40Nb alloy in terms of corrosion and bioactivity properties. Electrochemical anodization at different voltages was used to synthesize (Ti,Nb)O2 nanostructures (nanopores (NPs)) and (nanotubes (NTs)) on samples' surfaces, allowing the analysis of their influence on performances related to those p...

Quantification of free volume variation ΔVf of hydrogenated Zr57Al10Cu15.4Ni12.6Nb5 metallic glasses ribbon was investigated through nanoindentation tests and differential scanning calorimetry (DSC). A numerical approach based on the free volume model has been used to estimate ΔVf after 1, 2, and 5 hours of Hydrogen (H) charging time. The free volu...

A materials’ structure and its evolution due to friction play a crucial role in understanding wear and related processes. So far, structural changes caused by friction are mostly studied using ex situ destructive characterization techniques, such as microscopy of post-mortem the prepared specimen by polishing and etching techniques. In this paper,...

Fe-based bulk metallic glass (BMG) presents unique tribological and electrochemical properties. Given the inherent brittle nature and dimensional limitations of Fe-based BMGs, technological and scientific efforts are focused on their use for surface engineering solutions. Fe-based BMG coatings are promising to protect steel components operating in...

The possibility of forming coatings with a high content of amorphous phase by knock (detonation) spraying of a powder of alloy Fe66Cr10Nb5B19 of fraction 45 – 75 μm is considered. Results of comparative tests of the coatings and of a stainless steel check test piece for abrasive wear under friction against nonrigidly fixed abrasive particles conduc...

Al2O3 particle-modified Fe66Cr10Nb5B19 metallic glass matrix coatings were deposited on carbon steel substrates by detonation spraying of the corresponding powder mixtures. The microstructure, mechanical and tribological properties of the coatings were investigated. In the microstructure of the coatings, the Al2O3 particles were located between the...

A metastable beta TMZF alloy was tested by isothermal compression under different conditions of deformation temperature (923 to 1173 K), strain rate (0.172, 1.72, and 17.2 s⁻¹), and a constant strain of 0.8. Stress–strain curves, constitutive constants calculations, and microstructural analysis were performed to understand the alloy’s hot working b...

At present, metallic glasses are evaluated as alternative reinforcements for aluminum matrix composites. These composites are produced by powder metallurgy via consolidation of metallic glass-aluminum powder mixtures. In most studies, the goal has been to preserve the glassy state of the reinforcement during consolidation. However, it is also of in...

In this work, it was mapped combinations of anodization conditions, annealing temperatures, and elastic modulus together with better wettability properties of low elastic modulus Ti40Nb alloy. The anodization was realized in an organic electrolyte for one hour. Thus (Ti,Nb)O2 nanostructures grew on the surface. For the sake of optimizing the wettab...

The influence of chromium concentration and partial crystallization on the corrosion resistance of the FeCrNiB amorphous alloys was investigated. The samples were produced by melt-spinning equipment. Vacuum heat treatments were used for partial and total crystallization. The study methods used were: X-ray diffraction, differential scanning calorime...

In the present work, Fe66Cr10Nb5B19 metallic glass coatings deposited by detonation spraying (DS) on carbon steel substrates were structurally characterized and tested in 3.5 wt.% NaCl solutions with pH values of 3.0, 5.5, and 10.0 under potentiodynamic polarization conditions. The coatings had low porosity (2.9-4.5%) and showed a predominantly amo...

This work deals with iron-based amorphous alloys in the form of coatings and sintered materials. It compares the structure and properties of Fe-Cr-Nb-B alloys (Fe66Cr10Nb5B19 and Fe62Cr10Nb12B16) produced by detonation spraying and spark plasma sintering. The Fe66Cr10Nb5B19 alloy has a higher glass-forming ability than Fe62Cr10Nb12B16 and the gas-a...

Pseudo-high entropy (PHE) amorphous alloys have emerged as novel metallic materials. Some Fe-containing PHE amorphous alloys display the unique characteristic of maintaining a clustered glassy structure in a wide temperature range, and eventually crystallize multi-principal element (MPE) phases whose composition is close to the parental alloy compo...

Metastable alloys based on the Ti-Nb system are considered promising candidates to replace the biomaterials currently used in medicine. Several very promising alloys like TNTM, TNZT, etc., were recently developed by adding Zr, Ta, Mo, Fe, or other elements to the Ti-Nb system. However, only a few fundamental studies were devoted to the structural c...

This work studied the corrosion behaviour of Ti-12Mo-6Zr-2Fe alloy with different surface conditions: untreated and chemically treated (CST), anodised nanotubes (Nt) and nanopores (NP). These samples were immersed in simulated body fluid (SBF) for 1, 7, and 14 days. Samples with Nt and NP displayed higher corrosion resistance and lower passivation...

In this study, the effect of nickel content in two kinds of supermartensitic stainless steels, the new composition SMSS + Ni and already known SMSS–Ni, is compared concerning their mechanical properties as a function of tempering temperatures. The SMSS + Ni showed a microstructure composed of well-distributed thin martensite within austenite. In co...

Background Nanostructured surface modifications of Ti-based biomaterials are moving up from a highly-promising to a successfully-implemented approach to developing safe and reliable implants. Methods The study’s main objective is to help consolidate the knowledge and identify the more suitable experimental strategies related to TiO2 nanotubes-modi...

The TiNbZrHfTa high entropy alloy was studied for its use as a base material for orthopedic implants. The alloy produced by arc melting contains only biocompatible elements and has an attractive combination of mechanical properties with a tensile strength of 1050 MPa and Young's modulus of 66 GPa. Surface modification techniques were carried out to...

Laser materials processing is a very attractive technology, due not only to the vast number of applications in a wide range of materials and industrial segments but also due to the constant progress in the development of laser devices in terms of power, control, and costs. In metals processing technology, a high and precisely controlled density of...

The metastable β-type Ti-12Mo-6Zr-2Fe alloy was subjected to an assessment of its fatigue mechanical behavior. Promising tensile and fatigue properties were obtained when the alloy was solution treated and quenched, because nanocrystalline particles of ω phase were formed throughout the β matrix. When the material was subjected to a protocol of che...

In this work, we traced structural transformations of an Al62.5Cu25Fe12.5 alloy, in which a quasicrystalline icosahedral phase (i-phase) can be formed, upon spraying onto a substrate and consolidation from the powder into the bulk state. The Al62.5Cu25Fe12.5 powder was obtained by gas atomization and consisted of i-phase and ?-phase AlCu(Fe). The p...

In this study, the MgAlTiFeNi high entropy alloy was processed by high-energy ball milling under both argon and hydrogen atmospheres. It is shown that this alloy forms a body-centered cubic (BCC) structure when milled under an argon atmosphere (mechanical alloying-MA) and a combination of BCC, FCC, and Mg2FeH6 when milled under hydrogen pressure (r...

The conflicting role of crystalline phase on the corrosion and wear resistance of the glass former Fe66Cr10Nb5B19 alloy was investigated. Amorphous to crystalline structures were produced by amorphous ribbons annealing and solidification of the liquid into a wedge-shaped copper mold. Amorphous and amorphous/nanocrystalline microstructures displayed...

Hot torsion tests were carried out to simulate the industrial thermomechanical processing of two austenitic steels for bioimplant applications, namely ISO 5832-9 and ASTM F138. The former has Ti, Nb, and V in the composition, being N-rich. However, the latter is Ni-richer and without extra alloying element additions. Special attention was paid to t...

In the area of metal matrix composites, novel reinforcing options are currently being evaluated. Particles of amorphous alloys present an interesting possibility to reinforce soft metals. In the present work, the interaction between Fe66Cr10Nb5B19 metallic glass and aluminum during Spark Plasma Sintering (SPS) was studied for the first time. In ord...

It is well known that a balance between the generation of low-angle and high-angle grain boundaries (LABG and HAGB) is achieved in materials undergoing a severe plastic deformation (SPD) process. It is also observed that most annealed materials evolve from a substantial fraction of LAGB at the early deformation steps towards a steady state in which...

In this study, we describe an experimental setup and a new approach for operando investigation of structural evolution of materials during wear and friction. The setup is particularly suited for testing various friction pairs, including those in which both rubbing bodies are made of metals. The developed device allows circumventing the problems rel...

We show that, using thermo-elastic processing, metallic-glass foils can be shaped, without being embrittled, into linear and annular wave springs. These springs exhibit an undulatory behaviour, unique to metallic-glass foils, in which under compression the number of arcs in the spring increases, increasing the load-bearing capacity and the spring c...

Cast Al(5.5 to 6.3 wt pct)Si-(3.1 to 3.7 wt pct)Cu alloys containing 0.6 and 1.2 wt pct Fe were processed by spray forming, rotary swaging, and homogenization/solution heat treatment, which led to a tensile ductility of 16 pct. Such outstanding ductility is ascribed to the microstructure formed: globular silicon particles, refined iron-rich interme...

In this work, we present a wear-resistant coating fabricated by non-vacuum electron beam cladding of Fe62Cr10Nb12B16 at.% powder on a mild steel substrate. The protective coating was 1.3 mm thick, dense, and exhibited an α-(Fe,Cr) matrix reinforced by a significant fraction of hard borides formed upon solidification. Micrometric and nanometric bori...

In this work, we present a wear-resistant coating fabricated by non-vacuum electron beam cladding of Fe62Cr10Nb12B16 at.% powder on a mild steel substrate. The protective coating was 1.3 mm thick, dense, and exhibited an α-(Fe,Cr) matrix reinforced by a significant fraction of hard borides formed upon solidification. Micrometric and nanometric bori...

In this work, the corrosion behavior of amorphous and partially crystallized Fe68Cr8Mo4Nb4B16 alloys has been studied. Fully amorphous ribbons were prepared by melt spinning and then partially and fully crystallized at different heat treatment temperatures. The corrosion behavior was evaluated in chloride-rich media at different pHs, ranging from a...

The temperature and dynamic pressure of the detonation products are parameters that determine the heating and acceleration of particles during the detonation spraying. These parameters depend on the composition of the explosive mixture. The present article reports the influence of the composition of the acetylene–oxygen explosive mixture on the str...

A silver-based nanoporous material was produced by dealloying (selective chemical etching) of an Ag38.75Cu38.75Si22.5 crystalline alloy. Composed of connected ligaments, this material was imaged using a scanning electron microscope (SEM) and focused ion-beam (FIB) scanning electron microscope tomography. Its mechanical behavior was evaluated using...

Ti13Nb13Zr and Ti35Nb7Zr5Ta alloys containing non-cytotoxic elements for bone tissues can be the right choice for replacing Ti6Al4V for orthopedic implant applications. Formation of ultrafine-grained (UFG) structure in metals and alloys by severe plastic deformation (SPD) techniques allows the achievement of unique mechanical properties. Using high...

The present work was aimed to demonstrate the possibility of forming Fe66Cr10Nb5B19 metallic glass coatings by detonation spraying and analyze the coating formation process. A partially amorphous Fe66Cr10Nb5B19 powder with particles ranging from 45 µm to 74 µm in diameter was used to deposit coatings on stainless steel substrates. The deposition pr...

Ti alloys have been intensely used for human implants due to its excellent characteristics, like bio-inertness, low density, and corrosion resistance. However, some alloying elements were found to be toxic for the human body, which restricts the use of some alloys. Furthermore, there are two additional and essential aspects to be considered. The fi...

β Ti-Nb BCC alloys are potential materials for hydrogen storage in the solid state. Since these alloys present exceptional formability, they can be processed by extensive cold rolling (ECR), which can improve hydrogen sorption properties. This work investigated the effects of ECR accomplished under an inert atmosphere on H2 sorption properties of t...

Hot extrusion processing was used for producing bulk samples of 2MgFe mixtures adequate to hydrogen storage. High-energy ball milling was used to prepare 2MgFe powder mixtures, which were cold-pressed into cylindrical pre-forms. Such pre-forms were then processed by hot extrusion (at 300 °C and extrusion ratio of 3/1) to produce bulk samples. In th...

Here we report for the first time that the anodization of the biphasic (α'+β)Ti13Nb13Zr alloy form arrays of TiO 2 nanotubes with well-defined circular geometry in the α′ phase, while nanopores of TiO 2 are formed in the β phase. Samples of the Ti13Nb13Zr alloy were severely plastic deformed using High-Pressure Torsion (HPT)to refine the microstruc...

Background Nanophase surface properties of titanium alloys must be obtained for a suitable biological performance, particularly to facilitate cell adhesion and bone tissue formation. Obtaining a bulk nanostructured material using severe plastic deformation is an ideal processing route to improve the mechanical performance of titanium alloys. By dec...

In this study, using a combination of several experimental and computational methods, an attempt to improve the understanding of some important phenomena accompanying the process of explosive welding is made. The high-speed shooting was used to observe the formation of a re-entrant jet. Various methods of the materials characterization were used to...

The composition of a commercial duplex stainless steel was modified with boron additions (3.5, 4.5, and 5.5 wt.%) and processed by rapid-quenching techniques: Melt-spinning, copper-mold casting, and high-velocity oxygen fuel (HVOF). Spray deposition was also used to produce alloys as the process may induce rapid-solidified-like microstructures. The...

In this study, using a combination of several experimental and computational methods, an attempt to improve the understanding of some important phenomena accompanying the process of explosive welding is made. The high-speed shooting was used to observe the formation of a re-entrant jet, which removes contamination from the surface layers of the col...

ARMCO iron processed by ECAP up to a maximum equivalent strain of sixteen ECAP passes following route Bc was investigated by Electron Back Scattering Diffraction (EBSD), Transmission Electron Microscopy (TEM), TEM-EBSD and X-ray Diffraction Line Profile Analysis (XRDLPA). Different values of grain size were obtained with each technique. The lower v...

The mechanically alloyed Al82La10Ni4Fe4 glassy powder displays a two-step devitrification characterized by the precipitation of fcc-Al together with small amounts of the intermetallic Al11La3 phase in the first crystallization. The interface-controlled growth mechanism governed the first crystallization event. Calculations of the activation energy,...

The thermal stability of ARMCO iron processed by equal-channel angular pressing (ECAP) up to a true strain of 16 was investigated by differential scanning calorimetry (DSC). Particularly, the analysis was focused on deriving the recrystallization behavior (onset, peak, and offset temperatures) at three different heating rates (10, 20, and 40 °C/min...

Typically, aluminum alloys are contaminated by iron during recycling cycles. Such a procedure leads to the formation of intermetallic phases with detrimental morphology, which acts as stress risers, impairing mechanical properties and consequently hindering further mechanical processing and restricting recycling. This paper aimed at studying the so...

This work reports on the degradation of two (Zn-poor and Zn-rich) Mg-Zn-Ca crystalline alloys produced by mold casting yielding different kinds of microstructures with several scales. The dependence of corrosion properties and hydrogen evolution with alloy compositions, sizes and kinds of microstructure was exhaustively analyzed. The results were c...

The body-centered cubic (BCC or β) titanium alloys are attractive materials for hydrogen storage applications, due to their relatively high absorption capacities that can be attained in some cases, even at room or moderate temperatures. It is known that the ball milling techniques improve the H-absorption/desorption kinetics. Thus, different compos...

This study focuses on the fabrication and microstructural investigation of Cu–TiH2–C and Cu–Ti–C nanocomposites with different volume fractions (10% and 20%) of TiC. Two mixtures of powders were ball milled for 10 h, consequently consolidated by spark plasma sintering (SPS) at 900 and 1000 °C producing bulk materials with relative densities of 95–9...

Mechanically milled FeCrNbB feedstock powders from commercial precursors were used to produce amorphous coatings through two different industrial thermal-spraying techniques: high-velocity oxygen fuel (HVOF) and flame spraying. Microstructure, thermal behavior, and hardness of the coatings and their corrosion resistances in acidic and alkaline chlo...

Mg - 40 wt % TiFe nanocomposite was prepared by high-energy ball milling, HEBM, aiming improved hydrogen absorption at room temperature (RT). Four processing routes were chosen to separately investigate the effects of TiFe addition, HEBM processing and dispersion of TiFe particles, being: Route 1 – mechanical mixture of Mg and TiFe powders; Route 2...

The thermal stability of ARMCO iron processed by equal-channel angular pressing (ECAP) up to a true strain of 16 was investigated by differential scanning calorimetry (DSC). Particularly, the analysis was focused on deriving the recrystallization behavior (onset, peak, and offset temperatures) at three different heating rates (10, 20, and 40 A degr...

Magnesium (Mg) is a light metal with relatively low cost. Its hydride (MgH2) is interesting for the safe hydrogen storage in solid state and has a high gravimetric capacity of 7.6%. Practical application of Mg is still hampered by high reaction temperatures and slow kinetics. In order to improve it and focus on more viable industrial processing con...

Biomedical devices currently in use (prostheses, implants) have satisfactory performance in many cases. However, sometimes the body reacts to the device insertion and may lead to its rapid replacement. Some of these disadvantages can be solved by the use of titanium and its alloys, due to their excellent combination of corrosion resistance, wear re...

TiO2 nanotubes constitute a relevant surface modification technique to improve the surface properties of orthopedic implants. However, the interpretation of their electrochemical characterization by impedance spectroscopy in physiological environments remains unclear. The present study proposes a “Two-channel transmission line model” based on the d...

This investigation was conducted to evaluate the effect of cold rolling on the structure and hydrogen properties of two magnesium alloys, AZ91 and AM60D, after processing by equal-channel angular pressing (ECAP). The results show that the use of cold rolling after ECAP significantly increases the preferential texture for hydrogenation and increases...

In this work, the structural evolution of Al–16 at.%Fe–2 at.%TM (Transition Metals (TM): Ti, Ni, Cu) alloys during mechanical alloying and their magnetic properties were investigated. The evolution of the phase composition and microstructure of the alloys with the milling time was studied using X-ray diffraction (XRD) and Transmission Electron Micr...

The influence of Cr addition in a rapidly solidified Al-Ni-Co alloy was investigated. Melt spun samples of atomic composition Al71Ni20Co9, Al72Ni19Co7Cr2 and Al72Ni20Co5Cr3 were studied by X-ray diffraction and transmission electron microscopy. Aiming to develop quasicrystalline compositions enriched in corrosion resistant elements such as Cr and N...

During an explosion, the interfaces of welded materials experience fast heating due to high strain rate severe plastic deformation. This leads to the formation of local zones, where melting and mixing of welded materials is observed. These zones are frequently referred to as vortexes, eddies or swirls, due to the specific rotational movement of mat...

In this study, the effect of copper on the structure and properties of cast iron is discussed. The experimental samples, with copper content from 0.09 wt% to 14.2 wt%, were synthesized in an induction furnace. The structure of the samples was characterized using light microscopy (LM), scanning electron microscopy (SEM) and transmission electron mic...

Mixtures of XMg–Co containing different amounts of Mg (X = 2, 3 and 7) were reactive milled under hydrogen atmosphere. 2Mg–Co only formed the Mg2CoH5 complex hydride, while the mixtures 3Mg–Co and 7Mg–Co formed different contents of Mg2CoH5 and MgH2. Their structural features and hydrogen storage properties were analyzed by different techniques. In...

To study the synergetic influence of TiO2 nanotubes (NTs) morphology and crystalline structure on their electrochemical performances and apatite-forming ability, various sizes of nanotubes were synthesized via anodic oxidation of Ti and then annealed at different temperatures. XRD analysis and SEM observations confirmed that as-anodized amorphous n...