Zn alloys are currently investigated as a new generation of orthopedic implants due to their moderate biodegradability and favorable biocompatibility. However, during high-temperature alloying, significant grain growth and localized stress concentrations developing, compromising their mechanical properties. In this study, low-temperature sintered Zn-Al-Mg alloys were successfully prepared as low as 360 °C under pressure of 15 kN. Microstructure analysis revealed that Mg interacted and combined with Zn under the low temperature and high pressure, inducing uniformly lamellar eutectic phase that facilitated grain refinement and relieved stress concentrations, thereby improving load-bearing capacity. The Zn-Al-Mg alloys exhibited optimal mechanical properties: ultimate compressive strength of 270.8 ± 4.5 MPa, strain ratio of 7.6 ± 0.2%, and Vickers hardness of 90.9 ± 0.8 HV. Furthermore, the alloys demonstrated uniform corrosion characteristics in immersion test, and their biodegradation rate increased with higher Mg content. After biodegradation, the Zn-Al-Mg alloys exhibited good cytocompatibility with mouse osteoblasts, and displayed favorable histocompatibility following 8 weeks of implantation, collectively demonstrating strong biocompatibility. Overall, the low-temperature sintered Zn-Al-Mg alloys with enhanced strength are promising orthopedic implants.

Zr48Cu47.5Al4Co0.5 bulk amorphous alloy composites were prepared by selective laser melting (SLM) technology under different processing conditions and their non-isothermal crystallization behaviors were systematically investigated. The results show that the crystallization phases are Cu10Zr7 and CuZr2 for both gas-atomized powder and SLMed samples. The dependence of volume fraction of Cu10Zr7 and CuZr2 on laser energy density can be fitted by an exponential function. The crystalline sizes of Cu10Zr7 and CuZr2 linearly increase with increasing energy density. The thermal stability is larger for the gas-atomized powders than for the SLMed bulk samples. It is interestingly found that there is an exponential relationship between the crystallization enthalpy ΔHx and the amorphous content. In addition, the glass transition is more difficult for the gas-atomized powders than for the SLMed bulk samples. The crystallization procedure is more difficult for the SLMed bulk samples than for the gas-atomized powders. The local activation energy Eα decreases with increasing α for the gas-atomized powder and the SLMed bulk samples. In addition, the Eα is larger for the SLMed bulk samples than for the gas-atomized powder at the corresponding crystallization fraction α. The dependence of the local Avrami exponent n(α) on the α is similar for both the gas-atomized powders and the SLMed bulk samples at studied heating rates. The crystallization mechanism is also discussed.

Hybrid design is a key method for optimizing the performance of triply periodic minimal surface (TPMS) lattices, where the relationship between configuration parameters and deformation behavior is critical for performance enhancement. In this study, a series of hybrid lattices were constructed based on Primitive (P) and Gyroid (G) lattices using Sigmoid function, with the weighting parameter (k) and volume proportion serving as key configuration parameters, and their mechanical responses were systematically analyzed. The weighting parameter inversely controls hybridization width and directly governs hybridization - induced distortion. Higher k values yield narrower hybridization zones with greater distortion. Conversely, lower k values produce wider, smoother transitions with reduced distortion but significantly altered pore geometry. Both irregular pores and hybridization distortions induce stress concentrations, leading to nonuniform stress distributions. The mechanical behavior is primarily governed by volume proportion rather than weighting parameter. Under perpendicular loading, uniform crushing occurs with strain hardening. While parallel loading shows a transition from G - dominated to P - dominated graded crushing as the P - content decreases, accompanied by a shift from pore buckling to strain hardening behavior. The balanced configuration (k = 1, 50% P/G ratio) achieves optimal stress uniformity, deformation compatibility, and isotropic performance.

This study investigates the effects of ferromagnetic elements on the glass-forming ability (GFA) and soft magnetic properties of Fe-B-C-based amorphous alloys. By combining microalloying with longitudinal magnetic field annealing (LFA) treatment, Fe-based amorphous alloys with high saturation magnetization ( B-s ), low coercivity ( H-c ), and excellent manufacturability were successfully developed. The results demonstrate that the addition of Co or Ni improves the GFA of Fe86B7C7 amorphous alloys, while an optimal amount of Co or a minor addition of Ni significantly enhances B(s )of the alloys. Among the investigated alloys, the Fe78Co5Ni3B7C7 alloy exhibits superior soft magnetic performance, achieving B-s of 1.80 T and H(c )of 2.9 A/m. Additionally, the influence of LFA on the microstructure and magnetic properties was explored, with magneto-optical Kerr microscopy employed to analyze magnetic domain behavior. The results reveal that LFA modifies the magnetic domain orientation, aligning the easy magnetization axis with the ribbon direction, thus enhancing the alloy's soft magnetic properties. These findings offer significant understanding for enhancing the properties of Fe-based amorphous alloys, which could be beneficial for their use in electronic devices.

A novel Ti-6Al-1.7Fe-0.1Si-7.3Cr alloy was designed using high-throughput diffusion couple technique. The heat treatment effects on the microstructure and tensile properties of the designed alloy was investigated. The results indicated that the alloys after solution treatment at 800 degrees C/840 degrees C and aging at 400 degrees C/470 degrees C exhibited high strength (>1200 MPa) and good ductility (>5 %) due to the synergy of spherical alpha(p) phase, coarse flake alpha(p) phase and acicular alpha s phase in the beta matrix. The precipitation of TiCr2 Laves phase at aging temperatures above 540 degrees C led to a decline in ductility. The absence of the spherical alpha(p) phase for the alloy after solution treatmen at 920 degrees C also resulted in the deterioration of aging elongation. Good balances of strength and ductility were achieved for the alloys after solution treatment at 840 degrees C and aging at 400 degrees C/470 degrees C, with the ultimate tensile strength and tensile elongation of 1237 MPa/23.3 % and 1753 MPa/5.1 %, respectively. Furthermore, the deformation mechanism of the alloys was analyzed, and dislocation slip in alpha(p) phase and beta grain was demonstrated to be the main plastic deformation mode.

Non-isothermal aging (NIA) is a composite heat treatment process that involves heating aging, cooling aging, and complex solute precipitation sequences. The precipitation behavior and the strengthening and toughening mechanisms of the 2014 Al alloy during NIA were studied by employing tensile, fatigue crack growth, hardness, and electronic conductivity tests, as well as high-resolution transmission electron microscopy and scanning electron microscopy. The results show that during NIA, the B ' phase exhibits a complex process of nucleation, nucleation and growth, nucleation and growth and coarsening, growth and coarsening, nucleation and growth, and nucleation. NIA treatment imparts a mixed precipitation characteristic on the alloy, which is manifested as coherent precipitates, including GP zones, B '' phases, small-sized B ' phases, and semi-coherent or non-coherent precipitates such as large-sized B ' phases and equilibrium B phases. The simultaneous strengthening and toughening of the NIA-treated 2014 Al alloy is caused by the synergistic effects of the particle-shearing mechanism and Orowan bypassing mechanism.

Biomedical Fe-30Mn alloy was a promising alternative for the repair of load-bearing bone defects, but its applications were largely limited by slower degradation rate than growth rate of natural bone. The accelerated corrosion mechanisms of secondary phase MnS in Fe-30Mn-S biocomposite were proposed in the study. Detailly, the MnS with a lower corrosion potential preferentially corroded and thereby increased corrosion active sites. Moreover, adsorbed S element produced by the corrosion of MnS weakened the metal-metal bond of Fe. Meanwhile, Cl- with a small ion radius easily penetrated through degradation products, which made corrosive media inside corrosion pits more aggressive. Thus, the Fe-30Mn-S biocomposite tended to vertically expand during corrosion evolution, and caused rapid corrosion with a considerably increased corrosion rate of 0.41 mm y- 1. Besides, the Fe-30Mn-S biocomposite presented an ultimate compressive strength of 687 f 22 MPa, compressive yield strength of 402 f 23 MPa, microhardness of 280.4 f 5.8 HV, and favorable cytocompatibility. These results indicated that Fe-30Mn-S biocomposite with accelerated corrosion effects by secondary phase could be a promising candidate for bone repair.

Zn with moderate biodegradation rate and favorable biocompatibility is emerging as promising bone implants. However, inadequate mechanical strength of Zn impedes its widespread clinical use. In this study, a novel high strength Zn-Al alloy was developed by combining micro-alloying Sn and spark plasma sintering. The fine grain structure generated the large grain boundary area, which exhibited high resistance mechanical loading. Meanwhile, the Zn-Sn eutectic could hinder dislocation motion and caused strengthening. As a result, the ultimate compressive strength was greatly increased by 103.8 %, from 121.06+1 MPa for Zn alloy to 246.80+5.29 MPa for Zn-Al-Sn alloy, and the hardness was greatly increased by 69.7 %. Furthermore, the cytocompatibility assessment also indicated that the Zn-Al-Sn alloy exhibited favorable biocompatibility with BMSCs. This study showed that the newly developed Zn-Al-Sn alloy had great potential to be next-generation bone-implants.

The bulk Zr48Cu47.5Al4Co0.5 amorphous alloy composites were successfully consolidated by spark plasma sintering under different sintering temperatures. Their mechanical, wetting and corrosion properties were investigated. The results show that the density and hardness increase firstly with increase in the sintering temperature, and then decrease when the sintering temperature exceeds 713K. The Cu10Zr7 and CuZr2 phases continuously grow up with increasing sintering temperature. The growth rate of the volume fraction is -3.5 times larger for the Cu10Zr7 than for the CuZr2 under present sintering conditions. The water contact angle decreases with increasing sintering temperature. In addition, the corrosion potential of the 713K-sintered sample is the highest. The corrosion current density of the 673K-sintered sample is 2-3 times larger than that of the other samples under higher sintering temperatures. The growth mechanism for Cu10Zr7 and CuZr2 phases and the corrosion mechanism are also discussed.

A thermodynamic description for the Fe-Nd-B-Cr quaternary system has been developed on the basis of six constituent binary systems and four critical ternary systems using the CALPHAD (CALculation of PHAse Diagrams) method, which is based on the fact that a phase diagram is a representation of the thermodynamic properties of a system. The Fe-B binary system is modified, and Fe-Nd-Cr and Fe-Cr-B ternary systems are thermodynamically reassessed in order to obtain more reasonable thermodynamic parameters and more accurate phase relations. The assessment results for the Fe-Nd-Cr and Fe-Cr-B ternary systems are in good agreement with the available experimental phase relations, including the liquidus surface projection and the vertical sections, while for the other two ternary systems, the B-Nd-Cr and the Fe-Nd-B systems, the thermodynamic parameters are mainly adopted from optimization results reported in the literature, with slight modifications for the compatibility of all the constituent binary systems. Based on the metastable experimental information, a reasonable, self-consistent, and comprehensive thermodynamic description of the Fe-Nd-B-Cr quaternary system is developed, which is of interest for electronic and magnet materials. The developed thermodynamic description can be further extended as a thermodynamic database for permanent magnet alloy design.

Biomedical Fe, as novel load-bearing implants for clinical applications, is restricted by too slow degradation. Herein, Fe-CaSO4 biocomposite is prepared at low temperature of 700 degrees C. Subsequently, more corrosion active sites and micro-acidic environment produced by rapid dissolution of CaSO4 accelerate Fe biodegradation. Consequently, corrosion current density and corrosion rate of Fe-CaSO4 biocomposite greatly increases to 15.23 +/- 3.41 mu A.cm(-2) and 0.19 +/- 0.05 mm.y(-1), respectively. Meanwhile, charge transfer resistance of Fe-CaSO4 biocomposite was significantly reduced to 86.09% than that of Fe. Additionally, Fe-CaSO4 biocomposite exhibits enough strength up to 343 MPa and good cytocompatibility, indicating a great potential for clinical applications.

It is an intriguing and urgent goal to quantitatively or semi-quantitatively unveil the correlation between the properties and the microstructure for metallic glasses. The relationship between the microstructure and mechanical property of three Zr-based bulk metallic glasses (BMGs) were investigated. The results show that three BMGs have similar XRD patterns, crystallization behavior and comparable relaxation enthalpy. The precipitated phases of three fully crystallized BMGs are Zr6Al2Ni-type and CuZr2-type phases. The content of CuZr2-type phase increases but that of Zr6Al2Ni-type phase decreases with increasing Zr content. A remarkable discrepancy in plastic flow behavior in compression and nanoindentation tests originates from the different contents of CuZr2-type cluster named as the geometrically unfavorable motifs (GUMs). The plastic flow stress and strain decrease while the plasticity increases with increasing fraction of CuZr2-type cluster. The fitting parameters from cumulative probability statistics are fingerprints for investigating the plastic flow and plasticity of the BMGs, and would be a valuable clue for developing the BMGs with good plasticity. The mechanism of correlation between the GUMs and the plasticity was also discussed. This work would provide a favorable route for discovering the quantitatively correlation between the GUMs and the plasticity in the BMGs.

Three Cu-Zr-Ti plate-like amorphous alloy composite powders were prepared by ball milling the corresponding alloy powders. Their crystallization behaviors are systematically investigated by non-isothermal and isothermal modes. The phase transition during the ball milling would be Cu51Zr14 -> amorphous+Cu51Zr14 for Cu70Zr15Ti15, Cu51Zr14+Cu -> amorphous+Cu+Cu51Zr14 -> amorphous+Cu for Cu80Zr10Ti10, Cu+Cu3Ti -> amorphous+Cu for Cu90Zr5Ti5, respectively. The crystallization temperature increases according to the sequence of Cu70Zr15Ti15, Cu80Zr10Ti10 and Cu90Zr5Ti5. The crystallization phases are Cu3Ti and Cu for the isothermal crystallized Cu70Zr15Ti15, the nonisothermal and isothermal crystallized Cu80Zr10Ti10, and the nonisothermal crystallized Cu90Zr5Ti5. The crystallization phases are Cu51Zr14, Cu3Ti and Cu for the nonisothermal crystallized Cu70Zr15Ti15, while Cu for the isothermal crystallized Cu90Zr5Ti5. The detailed crystallization mechanism of nonisothermal and isothermal modes are discussed.

The microstructure and corrosion mechanisms of the detonation sprayed Fe-based amorphous coating on AZ31B magnesium alloy substrate were studied in detail by potentiodynamic polarization tests in 3.5 wt.% NaCl solution. The results show that the coating presents a typical amorphous structure, a fairly low porosity of less than 1%. Benefit from these structural advantages, the corrosion current density and impedance modulus are about 1/20 and 70 times that of AZ31B, respectively, which shows excellent corrosion resistance and protection. This distinguished corrosion resistance is mainly attributed to its unique disordered structure, uniform chemical composition, and the formation of uniform passive film on the surface, which hinders the invasion of chloride ions and prevents the further occurrence of corrosion. In addition, the ultra-high density of detonation sprayed coating also further hinders the penetration of corrosive media such as chloride ions, and provides a good corrosion protection for AZ31B.

锻造开坯变形均匀性是影响锻件质量的重要因素.以2A14铝合金为研究对象,利用Deform-3D有限元软件对锻坯应变场进行模拟,通过引入平均等效应变εave、变形均匀系数a,结合晶粒形貌观察和拉伸力学性能测试,对"单向镦粗"和"多向镦粗"两种锻造开坯工艺的变形均匀性进行定量和定性分析.研究结果表明:"多向镦粗"锻造开坯工艺的变形均匀性较"单向镦粗"锻造开坯工艺好,且锻造累积应变量越大,变形均匀性越好,力学性能各向异性越弱.2A14铝合金在多向镦粗锻造开坯过程中,随着累积应变量的增加,晶粒细化机制由晶粒破碎机制逐渐转变为连续动态再结晶机制.

The isochronal and isothermal crystallization characteristics of (Zr54Al10.2Ni9.4Cu26.4)(100-x)Ti-x (x = 0 similar to 0.5 at.%) bulk metallic glasses (BMGs) were investigated by differential scanning calorimetry. The isochronal crystallization indicates that both crystallization activation energy and local activation energy E-alpha of the Ti-free BMG are larger than those of the BMGs (x = 0.2 and 0.4), while smaller than those of the BMGs (x = 0.1, 0.3 and 0.5). The isothermal crystallization shows that the E(alpha)s decrease with increasing crystallization fraction for the first crystallization process and nearly maintain a constant for the second crystallization process. Moreover, the crystallization phases are ZrNi and Zr2Ni7 nanocrystals for the partially and/or fully crystallized BMGs in isochronal and isothermal cases. The crystallization mechanism nearly depends on the Ti content and the heating rate for the isochronal crystallization and the Ti content and the annealling temperature for the isothermal crystallization, respectively.

Amorphous alloys without crystalline defects (dislocation, crystal boundary) are ideal hydrophobic coating materials due to their low surface energy. This work used a synergistic method of detonation spraying and surface modification to obtain the superhydrophobic Fe-based amorphous coatings with high hardness and dense structure on the Q 235 substrate. The results showed that the water contact angles (WCA) of the superhydrophobic coating was 160° ± 3.6°, and water droplets could bounce off the superhydrophobic coating surface, illustrating the excellent self-cleaning performance of coating. Notably, the corrosion current density (icorr) of the superhydrophobic coating further decreased by 2 orders of magnitude down to 8.008 × 10−8 A·cm−2 compared to the as-deposited coating with 5.473 × 10−6 A·cm−2; the corrosion potential (Ecorr) of the superhydrophobic coating shifted by 34 mV to the positive side compared with that of the as-deposited coating (− 310 mV). Likewise, the impedance modulus |Z| values of the superhydrophobic coating increased by nearly 2 orders of magnitude up to 1×105.6 compared to the as-deposited coating with 1×103.8. Even through lasting immersion in NaCl for 10 days, |Z| values of the superhydrophobic coating were still much higher than those of the as-deposited coating. The superhydrophobic Fe-based amorphous coatings could respond to their applications under extreme conditions due to their excellent hydrophobicity and self-cleaning properties, illustrating their promising future in aerospace, automotive, and machinery industries.

The Fe-based amorphous amorphous coating with a thickness of 150 mu m was prepared by detonation spraying. Under a constant strain rate (0.01 s-1 and 0.50 s-1) and a holding time of 50 s, the Fe-based amorphous coatings were subjected to room temperature nanoindentation creep tests with the penetration depth varying from 50 nm to 500 nm, then the depth-dependent creep deformation mechanism of Fe-based amorphous coating during nanoindentation tests were investigated in detail. The results show that the creep responses of coating obviously depend on the indentation penetration depth (hp) and the indentation load rate, i.e., the creep displacement of coating increases with the increase of hp and loading strain rate. This is mainly due to the rapid increase in the shear transition zone volume of the coating as the hp increases, making it easier for the shear band to be excited to nucleate, and results in an obvious creep deformation. Moreover, at high strain rates, the initiation rate of the free volume in the amorphous coating far exceeds its annihilation rate, resulting in a large amount of excess free volume in the amorphous coating, which makes it easier to excite multiple shear bands in the amorphous coating and cause creep plastic deformation.

A very thick (-1 mm) coating of Fe-based amorphous material was applied to a Q235 steel substrate by detonation spraying. The rate-dependent anelastic and viscoplastic deformations of the coating were investigated through nanoindentation creep experiments with loading rates of 0.1-5 mN s(-1); the results were analyzed using the Maxwell-Voigt model with two Kelvin units. Creep deformation in the Fe-based amorphous coating was found to be sensitive to loading rate; the nanohardness, creep-stress exponent, and viscosity lessened with increased loading rate during viscoplastic deformation. The presence of two characteristic peaks in the relaxation-time spectrum shows that the anelastic deformation was related to the activation of two types of defects. Low loading rates promoted the activation of defects in the soft region with long relaxation times; larger loading rates promoted the activation of defects in the hard region with shorter structural relaxation times, allowing plastic deformation. This resulted in lower creep resistance at higher loading rates.

The non-isothermal and isothermal crystallization behaviors are systematically investigated for the gas-atomized and as-milled amorphous alloy powders. The results show that the crystallization phase is Cu10Zr7 phase for the gas-atomized and as-milled amorphous alloy powders in non-isothermal and isothermal crystallization modes. The glass transition temperature, onset crystallization temperature, and crystallization peak temperature are larger for the as-atomized alloy powders than for the as-milled ones. The activation energies for the glass transition and crystallization are lower for the as-atomized alloy powders than for the as-milled ones. The crystallization mechanism of the gas-atomized and as-milled amorphous alloy powders nearly depends on the heating rates and the annealing temperatures. The detailed crystallization mechanism of non-isothermal and isothermal modes are discussed.