Biological Safety Evaluation and Surface Modification of Biocompatible Ti–15Zr–4Nb Alloy

We performed biological safety evaluation tests of three Ti–Zr alloys under accelerated extraction condition. We also conducted histopathological analysis of long-term implantation of pure V, Al, Ni, Zr, Nb, and Ta metals as well as Ni–Ti and high-V-containing Ti–15V–3Al–3Sn alloys in rats. The effect of the dental implant (screw) shape on morphometrical parameters was investigated using rabbits. Moreover, we examined the maximum pullout properties of grit-blasted Ti–Zr alloys after their implantation in rabbits. The biological safety evaluation tests of three Ti–Zr alloys (Ti–15Zr–4Nb, Ti–15Zr–4Nb–1Ta, and Ti–15Zr–4Nb–4Ta) showed no adverse (negative) effects of either normal or accelerated extraction. No bone was formed around the pure V and Ni implants. The Al, Zr, Nb, and Ni–Ti implants were surrounded by new bone. The new bone formed around Ti–Ni and high-V-containing Ti alloys tended to be thinner than that formed around Ti–Zr and Ti–6Al–4V alloys. The rate of bone formation on the threaded portion in the Ti–15Zr–4Nb–4Ta dental implant was the same as that on a smooth surface. The maximum pullout loads of the grit- and shot-blasted Ti–Zr alloys increased linearly with implantation period in rabbits. The pullout load of grit-blasted Ti–Zr alloy rods was higher than that of shot-blasted ones. The surface roughness (Ra) and area ratio of residual Al₂O₃ particles of the Ti–15Zr–4Nb alloy surface grit-blasted with Al₂O₃ particles were the same as those of the grit-blasted Alloclassic stem surface. It was clarified that the grit-blasted Ti–15Zr–4Nb alloy could be used for artificial hip joint stems.     

Biomechanical Behavior of Narrow Dental Implants Made with Aluminum- and Vanadium-Free Alloys: A Finite Element Analysis

Titanium (Ti) alloys used for narrow dental implants usually contain aluminum (Al) and vanadium (V) for improved resistance. However, those elements are linked to possible cytotoxic effects. Thus, this study evaluated the biomechanical behavior of narrow dental implants made with Al- and V-free Ti alloys by the finite element method. A virtual model of a partially edentulous maxilla received single implants (diameter: 2.7 and 2.9 mm; length: 10 mm) at the upper lateral incisor area, with respective abutments and porcelain-fused-to-metal crowns. Simulations were performed for each implant diameter and the following eight alloys (and elastic moduli): (1) Ti–6Al–4V (control; 110 GPa), (2) Ti–35Nb–5Sn–6Mo–3Zr (85 GPa), (3) Ti–13Nb–13Zr (77 GPa), (4) Ti–15Zr (113 GPa), (5) Ti–8Fe–5Ta (120 GPa), (6) Ti–26.88Fe–4Ta (175 GPa), (7) TNTZ–2Fe–0.4O (107 GPa), and (8) TNTZ–2Fe–0.7O (109 GPa). The implants received a labially directed total static load of 100 N at a 45° angle relative to their long axis. Parameters for analysis included the maximum and minimum principal stresses for bone, and von Mises equivalent stress for implants and abutments. Ti–26.88Fe–4Ta reaches the lowest maximum (57 MPa) and minimum (125 MPa) principal stress values, whereas Ti–35Nb–5Sn–6Mo–3Zr (183 MPa) and Ti–13Nb–13Zr (191 MPa) models result in the highest principal stresses (the 2.7 mm model surpasses the threshold for bone overload). Implant diameters affect von Mises stresses more than the constituent alloys. It can be concluded that the narrow implants made of the Ti–26.88Fe–4Ta alloy have the most favorable biomechanical behavior, mostly by mitigating stress on peri-implant bone.     

Microstructure,Micro-Mechanical and Tribocorrosion Behavior of Oxygen Hardened Ti–13Nb–13Zr Alloy

In the present work, an oxygen hardening of near-β phase Ti–13Nb–13Zr alloy in plasma glow discharge at 700–1000 °C was studied. The influence of the surface treatment on the alloy microstructure, tribological and micromechanical properties, and corrosion resistance is presented. A strong influence of the treatment on the hardened zone thickness, refinement of the α’ laths and grain size of the bulk alloy were found. The outer hardened zone contained mainly an oxygen-rich Ti α’ (O) solid solution. The microhardness and elastic modulus of the hardened zone decreased with increasing hardening temperature. The hardened zone thickness, size of the α’ laths, and grain size of the bulk alloy increased with increasing treatment temperature. The wear resistance of the alloy oxygen-hardened at 1000 °C was about two hundred times, and at 700 °C, even five hundred times greater than that of the base alloy. Oxygen hardening also slightly improved the corrosion resistance. Tribocorrosion tests revealed that the alloy hardened at 700 °C was wear-resistant in a corrosive environment, and when the friction process was completed, the passive film was quickly restored. The results show that glow discharge plasma oxidation is a simple and effective method to enhance the micromechanical and tribological performance of the Ti–13Nb–13Zr alloy.     

From Mo–Si–B to Mo–Ti–Si–B Alloys: A Short Review

Mo–Si–B alloys have attracted considerable research interest during the last several decades due to their high melting points, excellent high-temperature strength and relatively good oxidation resistance. However, insufficient room-temperature fracture toughness and high-temperature oxidation resistance restrain their further application. Generally, a sufficient volume fraction of BCC-Mo solid-solution phase, providing the ductility, and a high Si content, responsible for the formation of passive oxide scales, is difficult to achieve simultaneously in this ternary system. Recently, macroalloying of Ti has been proposed to establish a novel phase equilibrium with a combination of enough BCC phase and intermetallic compounds that contain a large amount of Si. In this article, the development history from the ternary Mo–Si–B to the quaternary Mo–Ti–Si–B system was reviewed. It was found that the constitution phases could be easily tailored by changing the Ti content. In this regard, better performance of mechanical properties and oxidation resistance can be obtained through proper alloy design. In-depth understanding of the advantages of the quaternary alloys over their ternary ancestors may contribute to bringing about a new concept in designing novel ultra-high-temperature structural materials.     

Effects of SiC Fibers and Laminated Structure on Mechanical Properties of Ti–Al Laminated Composites

Ti/Ti–Al and SiC_f-reinforced Ti/Ti–Al laminated composites were fabricated through vacuum hot-pressure using pure Ti foils, pure Al foils and SiC fibers as raw materials. The effects of SiC fiber and a laminated structure on the properties of Ti–Al laminated composites were studied. A novel method of fiber weaving was implemented to arrange the SiC fibers, which can guarantee the equal spacing of the fibers without introducing other elements. Results showed that with a higher exerted pressure, a more compact structure with fewer Kirkendall holes can be obtained in SiC_f-reinforced Ti/Ti–Al laminated composites. The tensile strength along the longitudinal direction of fibers was about 400 ± 10 MPa, which was 60% higher compared with the fabricated Ti/Ti–Al laminated composites with the same volume fraction (60%) of the Ti layer. An in situ tensile test was adopted to observe the deformation behavior and fracture mechanisms of the SiC_f-reinforced Ti/Ti–Al laminated composites. Results showed that microcracks first occurred in the Ti–Al intermetallic layer.     

Investigations of Effects of Intermetallic Compound on the Mechanical Properties and Shape Memory Effect of Ti–Au–Ta Biomaterials

Owing to the world population aging, biomedical materials, such as shape memory alloys (SMAs) have attracted much attention. The biocompatible Ti–Au–Ta SMAs, which also possess high X–ray contrast for the applications like guidewire utilized in surgery, were studied in this work. The alloys were successfully prepared by physical metallurgy techniques and the phase constituents, microstructures, chemical compositions, shape memory effect (SME), and superelasticity (SE) of the Ti–Au–Ta SMAs were also examined. The functionalities, such as SME, were revealed by the introduction of the third element Ta; in addition, obvious improvements of the alloy performances of the ternary Ti–Au–Ta alloys were confirmed while compared with that of the binary Ti–Au alloy. The Ti₃Au intermetallic compound was both found crystallographically and metallographically in the Ti–4 at.% Au–30 at.% Ta alloy. The strength of the alloy was promoted by the precipitates of the Ti₃Au intermetallic compound. The effects of the Ti₃Au precipitates on the mechanical properties, SME, and SE were also investigated in this work. Slight shape recovery was found in the Ti–4 at.% Au–20 at.% Ta alloy during unloading of an externally applied stress.     

Enhanced Fluidity of ZL205A Alloy with the Combined Addition of Al–Ti–C and La

The effects of Al–Ti–C and La on the fluidity of a ZL205A alloy after separate and combined addition were studied by conducting a fluidity test. The fluidity of the ZL205A alloy first increased and then decreased with the increasing addition of Al–Ti–C and La; it peaked at 0.3% and 0.1% for Al–Ti–C and La, respectively. The combined addition of Al–Ti–C and La led to better fluidity, which increased by 74% compared with the base alloy. The affecting mechanism was clarified through microstructure characterization and a DSC test. The heterogeneous nucleation aided by Al–Ti–C and La, the number of particles in the melt, and the evolution of the solidification range all played a role. Based on the evolution of the fluidity and grain size, the optimal levels of Al–Ti–C and La leading to both high fluidity and small grain size were identified.     

A Review of Cu–Ni–Sn Alloys: Processing,Microstructure, Properties,and Developing Trends

Cu–Ni–Sn alloys have been widely used in the aerospace industry, the electronics industry, and other fields due to their excellent electrical and thermal conductivity, high strength, corrosion and wear resistance, etc., which make Cu–15Ni–8Sn alloys the perfect alternative to Cu–Be alloys. This paper begins with how Cu–Ni–Sn alloys are prepared. Then, the microstructural features, especially the precipitation order of each phase, are described. In addition, the influence of alloying elements, such as Si, Ti, and Nb, on its microstructure and properties is discussed. Finally, the effects of plastic deformation and heat treatment on Cu–Ni–Sn alloys are discussed. This review is able to provide insight into the development of novel Cu–Ni–Sn alloys with a high performance.     

Effect of Ga on the Oxide Film Structure and Oxidation Resistance of Sn–Bi–Zn Alloys as Heat Transfer Fluids

The effect of gallium on the oxide film structure and overall oxidation resistance of low melting point Sn–Bi–Zn alloys was investigated under air atmosphere using thermogravimetric analyses. The liquid alloys studied had a Ga content of 1–7 wt.%. The results showed that the growth rates of the surface scale formed on the Sn–Bi–Zn–Ga alloys conformed to the parabolic law. The oxidation resistance of Sn–Bi–Zn alloys was improved by Ga addition and the activation energies increased from 12.05 kJ∙mol⁻¹ to 22.20 kJ∙mol⁻¹. The structure and elemental distribution of the oxide film surface and cross-section were found to become more complicated and denser with Ga addition. Further, the results of X-ray photoelectron spectroscopy and X-ray diffraction show that Ga elements accumulate on the surface of the liquid metal to form oxides, which significantly slowed the oxidation of the surface of the liquid alloy.     

Fatigue Behavior of Linear Friction Welded Ti-6Al-4V and Ti-6Al-2Sn-4Zr-2Mo-0.1Si Dissimilar Welds

The use of joints fabricated from dissimilar titanium alloys allows the design of structures with local properties tailored to different service requirements. To develop welded structures for aerospace applications, particularly under critical loading, an understanding of the fatigue behavior is crucial, but remains limited, especially for solid-state technologies such as linear friction welding (LFW). This paper presents the fatigue behavior of dissimilar titanium alloys, Ti–6Al–4V (Ti64) and Ti–6Al–2Sn–4Zr–2Mo–0.1Si (Ti6242), joined by LFW with the aim of characterizing the stress versus number of cycles to failure (S-N) curves in both the low- and high-cycle fatigue regimes. Prior to fatigue testing, metallurgical characterization of the dissimilar alloy welds indicated softening in the heat-affected zone due to the retention of metastable β, and the typical practice of stress relief annealing (SRA) for alleviating the residual stresses was effective also in transforming the metastable β to equilibrated levels of α + β phases and recovering the hardness. Thus, the dissimilar alloy joints were fatigue-tested in the SRA (750 °C for 2 h) condition and their low- and high-cycle fatigue behaviors were compared to those of the Ti64 and Ti6242 base metals (BMs). The low-cycle fatigue (LCF) behavior of the dissimilar Ti6242–Ti64 linear friction welds was characterized by relatively high maximum stress values (~ 900 to 1100 MPa) and, in the high-cycle fatigue (HCF) regime, the fatigue limit of 450 MPa at 10⁷ cycles was just slightly higher than that of the Ti6242 BM (434 MPa) and the Ti64 BM (445 MPa). Fatigue failure of the dissimilar titanium alloy welds in the low-cycle and high-cycle regimes occurred, respectively, on the Ti64 and Ti6242 sides, roughly 3 ± 1 mm away from the weld center, and the transitioning was reasoned based on the microstructural characteristics of the BMs.     

The Formation of 14H-LPSO in Mg–9Gd–2Y–2Zn–0.5Zr Alloy during Heat Treatment

There is a new long-period stacking ordered structure in Mg–RE–Zn magnesium alloys, namely the LPSO phase, which can effectively improve the yield strength, elongation, and corrosion resistance of Mg alloys. According to different types of Mg–RE–Zn alloy systems, two transformation modes are involved in the heat treatment transformation process. The first is the alloy without LPSO phase in the as-cast alloy, and the Mg_xRE phase changes to 14H-LPSO phase. The second is the alloy containing LPSO phase in the as-cast state, and the 14H-LPSO phase is obtained by the transformations of 6H, 18R, and 24R. The effects of different solution parameters on the second phase of Mg–9Gd–2Y–2Zn–0.5Zr alloy were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The precipitation mechanism of 14H-LPSO phase during solution treatment was further clarified. At a solution time of 13 h, the grain size increased rapidly initially and then decreased slightly with increasing solution temperature. The analysis of the volume fraction of the second phase and lattice constant showed that Gd and Y elements in the alloy precipitated from the matrix and formed 14H-LPSO phase after solution treatment at 490 °C for 13 h. At this time, the hardness of the alloy reached the maximum of 74.6 HV. After solution treatment at 500 °C for 13 h, the solid solution degree of the alloy increases, and the grain size and hardness of the alloy remain basically unchanged.     

Synthesis and Characterization of Ti–Nb Alloy Films Obtained by Magnetron Sputtering and Low-Energy High-Current Electron Beam Treatment

The aim of the present work is to investigate the synthesis of Ti–Nb alloy films obtained by the physical vapor deposition (PVD) magnetron sputtering of Nb films on Ti substrates, followed by low-energy high-current electron beam (LEHCEB) alloying treatment. Ti–Nb alloys were synthetized under two different regimes, one by varying the deposited amount of Nb (from 25 to 150 nm) and treating samples with low applied voltages and a number of pulses (three pulses at either 20 or 25 kV), the second by setting the amount of Nb (100 nm) and alloying it at a higher applied voltage with a different number of pulses (from 10 to 50 at 25 and 30 kV). The synthetized Ti–Nb alloys were characterized by XRD and GDOES for phase identification and chemical composition; SEM and optical microscopy were employed for morphology evaluation; compositional investigation was done by EDS analysis and mechanical properties were evaluated by microindentation tests. LEHCEB treatment led to the formation of metastable phases (α′, α″ and β) which, together with the grain refinement effect, was responsible for improved mechanical properties.     

Microstructure and Wear Resistance of Laser-Clad Ni–Cu–Mo–W–Si Coatings on a Cu–Cr–Zr Alloy

To improve the wear resistance of high-strength and high-conductivity Cu–Cr–Zr alloys in high-speed and heavy load friction environments, coatings including Ni–Cu, Ni–Cu-10(W,Si), Ni–Cu–10(Mo,W,Si), and Ni–Cu–15(Mo,W,Si) (with an atomic ratio of Mo,W to Si of 1:2) were prepared using coaxial powder-feeding laser cladding technology. The microstructure and wear performance of coatings were chiefly investigated. The results revealed that (Mo,W)Si₂ and MoNiSi phases are found in the Ni–Cu–10(Mo,W,Si) and Ni–Cu–15(Mo,W,Si) coating. WSi₂ phases are found in the Ni–Cu–10(W,Si) coating. The degree of grain refinement in Ni–Cu–10(Mo,W,Si) was greater than that of the Ni–Cu–10(W,Si) coating after the effect of Mo. The excellent wear resistance and micro-hardness of the Ni–Cu–15(Mo,W,Si) coating were attributed to the increase in its dispersion phase, which were approximately 34.72 mg/km and 428 HV, 27.1% and 590% higher than the Cu–Cr–Zr substrate, respectively. The existence of silicide plays an important role in grain refinement due to the promotion of nucleation and the inhibition of grain growth. In addition, the wear mechanism transformed from adhesive wear in the Ni–Cu coating with no silicides to abrasive wear in the Ni–Cu–15(Mo,W,Si) coating with high levels of silicides.     

Morphological Evolution of TiB2 and TiAl3 in Al–Ti–B Master Alloy Using Different Ti Adding Routes

Three different Ti addition routes were used to prepare an Al–5Ti–B Master Alloy: the halide salt route, the Ti-sponge route, and the partial Ti-sponge route. In the halide salt route, the raw materials were Al + KBF₄ + K₂TiF₆; K₂TiF₆ was completely replaced by pure titanium for the Ti-sponge route versus the halide salt route; in the partial Ti-sponge route, K₂TiF₆ was partially replaced by pure titanium. Here, 30% Ti-sponge or 60% Ti-sponge route means that 30% or 60% K₂TiF₆ was replaced by pure titanium, respectively. The above Ti addition routes have a significant influence on the growth pattern and morphological evolution of TiAl₃ and TiB₂, which greatly affect the refining performance of Al–Ti–B Master Alloy. When using the halide salt route, a streamlined “rich Ti, B area” exists in the aluminum melt, which is a complex compound of (Ti_x, Al_1−x) B_y. The “rich Ti, B area” is essential for the nucleation and growth of TiAl₃ and TiB₂. Blocky TiAl₃ was obtained and its average size was 4.7 μm based on the halide salt route. In the Ti-sponge route, the nucleation of TiAl₃ mainly depends on the mutual diffusion of Al and Ti, and TiAl_x forms around pure Ti particles, i.e., the so-called Ti–TiAl_x mechanism. The average size of the blocky TiAl₃ was 9.8 μm based on the Ti–TiAl_x mechanism. For the partial Ti-sponge route, the “rich Ti, B area” gradually decreases with the increase in Ti powder’s contents, and large TiAl₃ coexists with the small TiAl₃. Compared with the Ti-sponge route, the halide salt route can form smaller TiAl₃. In the Ti-sponge route, there is a small amount of “rich Ti, B area” due to the influence of the Ti–TiAl_x mechanism, which does not meet the requirements of TiB₂ growth. In the halide salt route, there is sufficient “rich Ti, B area”, which is conducive to the formation of TiB₂. Both the crystal defects and the crowded growth environment caused by the “rich Ti, B area” are fundamental reasons for the fragility and the irregular shape of the TiB₂. The refining effect of the Al–Ti–B Master Alloy prepared by the halide salt route is better than the Ti-sponge route. The refining effect of 30% Ti-sponge route is better than that of Ti-sponge route and worse than that of halide salt route.     

Influence of Friction Stir Process on the Physical,Microstructural, Corrosive,and Electrical Properties of an Al–Mg Alloy Modified with Ti–B Additives

In this study, two successive methods were used to improve the grain structure and the mechanical and physical properties of Al 5052 aluminum alloy. The modifying elements, 0.99 wt.% of titanium (Ti) and 0.2 wt.% of boron (B), were added during the casting process. After solidification, single- and double-pass friction stir processing (FSP) were performed to achieve additional grain refinement and disperse the newly formed phases well. The addition of Ti–B modifiers significantly improved the mechanical and physical properties of the Al 5052 aluminum alloy. Nevertheless, only a 3% improvement in microhardness was achieved. The ultimate strength (US), yield strength (YS), and elastic modulus were investigated. In addition, the electrical conductivity was reduced by 56% compared to the base alloys. The effects of grain refinement on thermal expansion and corrosion rate were studied; the modified alloy with Ti–B in the as-cast state showed lower dimension stability than the samples treated with the FSP method. The grain refinement significantly affected the corrosion resistance; for example, single and double FSP passes reduced the corrosion rate by 11.4 times and 19.2 times, respectively. The successive FSP passes, resulting in a non-porous structure, increased the bulk density and formed precipitates with high bulk density.     

The Effect of Heat Treatment on the Tribological Properties and Room Temperature Corrosion Behavior of Fe–Cr–Al-Based OPH Alloy

The microstructure, mechanical, tribological, and corrosion properties of Fe–Cr–Al–Y-based oxide-precipitation-hardened (OPH) alloy at room temperature are presented. Two OPH alloys with a composition of 0.72Fe–0.15Cr–0.06Al–0.03Mo–0.01Ta–0.02Y₂O₃ and 0.03Y₂O₃ (wt.%) were prepared by mechanical alloying with different milling times. After consolidation by hot rolling, the alloys presented a very fine microstructure with a grain size of approximately 180 nm. Such a structure is relatively brittle, and its mechanical properties are enhanced by heat treatment. Annealing was performed at three temperatures (1000 °C, 1100 °C, and 1200 °C), with a holding time from 1 to 20 h. Tensile testing, wear testing, and corrosion testing were performed to evaluate the effect of heat treatment on the behavior and microstructural properties. The grain size increased almost 10 times by heat treatment, which influenced the mechanical properties. The ultimate tensile strength increased up to 300% more compared to the initial state. On the other hand, heat treatment has a negative effect on corrosion and wear resistance.     

Effect of Boron Doping on Cellular Discontinuous Precipitation for Age-Hardenable Cu–Ti Alloys

The effects of boron doping on the microstructural evolution and mechanical and electrical properties of age-hardenable Cu–4Ti (at.%) alloys are investigated. In the quenched Cu–4Ti–0.03B (at.%) alloy, elemental B (boron) is preferentially segregated at the grain boundaries of the supersaturated solid-solution phase. The aging behavior of the B-doped alloy is mostly similar to that of conventional age-hardenable Cu–Ti alloys. In the early stage of aging at 450 °C, metastable β′-Cu₄Ti with fine needle-shaped precipitates continuously form in the matrix phase. Cellular discontinuous precipitates composed of the stable β-Cu₄Ti and solid-solution laminates are then formed and grown at the grain boundaries. However, the volume fraction of the discontinuous precipitates is lower in the Cu–4Ti–0.03B alloy than the Cu–4Ti alloy, particularly in the over-aging period of 72–120 h. The suppression of the formation of discontinuous precipitates eventually results in improvement of the hardness and tensile strength. It should be noted that minor B doping of Cu–Ti alloys also effectively enhances the elongation to fracture, which should be attributed to segregation of B at the grain boundaries.     

Tailoring a Low Young Modulus for a Beta Titanium Alloy by Combining Severe Plastic Deformation with Solution Treatment

The present paper analyzed the microstructural characteristics and the mechanical properties of a Ti–Nb–Zr–Fe–O alloy of β-Ti type obtained by combining severe plastic deformation (SPD), for which the total reduction was of ε_tot = 90%, with two variants of super-transus solution treatment (ST). The objective was to obtain a low Young’s modulus with sufficient high strength in purpose to use the alloy as a biomaterial for orthopedic implants. The microstructure analysis was conducted through X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) investigations. The analyzed mechanical properties reveal promising values for yield strength (YS) and ultimate tensile strength (UTS) of about 770 and 1100 MPa, respectively, with a low value of Young’s modulus of about 48–49 GPa. The conclusion is that satisfactory mechanical properties for this type of alloy can be obtained if considering a proper combination of SPD + ST parameters and a suitable content of β-stabilizing alloying elements, especially the Zr/Nb ratio.     

The Effect of (Mg,Zn)12Ce Phase Content on the Microstructure and the Mechanical Properties of Mg–Zn–Ce–Zr Alloy

The quantitative study of rare earth compounds is important for the improvement of existing magnesium alloy systems and the design of new magnesium alloys. In this paper, the effective separation of matrix and compound in Mg–Zn–Ce–Zr alloy was achieved by a low-temperature chemical phase separation technique. The mass fraction of the (Mg, Zn)₁₂Ce compound was determined and the effect of the (Mg, Zn)₁₂Ce phase content on the heat deformation organization and properties was investigated. The results show that the Mg–Zn–Ce compound in both the as-cast and the homogeneous alloys is (Mg, Zn)₁₂Ce. (Mg, Zn)₁₂Ce phase formation depends on the content and the ratio of Zn and Ce elements in the initial residual melt of the eutectic reaction. The Zn/Ce mass ratios below 2.5 give the highest compound contents for different Zn contents, 5.262 wt.% and 7.040 wt.%, respectively. The increase in the amount of the (Mg, Zn)₁₂Ce phase can significantly reduce the critical conditions for dynamic recrystallization formation. Both the critical strain and the stress decrease with increasing rare earth content. The reduction of the critical conditions and the particle-promoted nucleation mechanism work together to increase the amount of dynamic recrystallization. In addition, it was found that alloys with 6 wt.% Zn elements tend to undergo a dynamic recrystallization softening mechanism, while alloys with 3 wt.% Zn elements tend to undergo a dynamic reversion softening mechanism.     

Wear and Corrosion Resistance of AlSi10Mg–CP–Ti Metal–Metal Composite Materials Produced by Electro-Sinter-Forging

Metal–metal composites are a class of composite materials studied for their high ductility and strength, but their potential applications are currently limited by the complex manufacturing processes involved. Electro-sinter-forging (ESF) is a single-pulse electro discharge sintering technique that proved its effectiveness in the rapid sintering of several metals, alloys, and composites. Previous studies proved the processability of Ti and AlSi10Mg by ESF to produce metal–metal composites and defined a correlation between microstructure and processing parameters. This paper presents the wear and corrosion characterizations of two metal–metal composites obtained via ESF with the following compositions: 20% Ti/80% AlSi10Mg and 20% AlSi10Mg/80% Ti. The two materials showed complementary resistance to wear and corrosion. A higher fraction of AlSi10Mg is responsible for forming a protective tribolayer in dry-sliding conditions, while a higher fraction of Titanium confers improved corrosion resistance due to its higher corrosion potential.