Wp/Zr55Cu30Al10Ni5 bulk metallic glass composites (Wp/Zr-BMGCs) with a tungsten (W) particle volume fraction of 30% was prepared by spark plasma sintering (SPS). The amorphous matrix of Wp/Zr-BMGCs was crystallized through annealing. The effects of crystallization of the amorphous matrix on the plastic deformation capacity of Wp/Zr-BMGCs were investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and a universal testing machine. Results indicate that at an annealing temperature of 743 K, the average plastic strain of Wp/Zr-BMGCs first increases and then decreases with increasing annealing time. After 60 s of annealing, nanocrystals formed in situ on the amorphous matrix of Wp/ Zr-BMGCs, with a relative crystallization degree of approximately 28.3%. At this stage, the average plastic strain reached its maximum value of approximately 10.7%. Compared to the unannealed Wp/Zr-BMGCs, the average plastic strain increased by approximately 69.8%. The increase in plastic strain of Wp/Zr-BMGCs is primarily due to the in-situ formed nanocrystals triggering the nucleation and propagation of more shear bands, thereby promoting the synergistic deformation of W particles and the amorphous matrix. However, as annealing time increased, crystallization accelerated, leading to the formation of brittle phases-Ni3Zr, CuAl2, and CuZr2-within the amorphous matrix. The material transitions from shear fracture failure to brittle failure dominated by crack propagation.

Amorphous composites of Wp/Zr55Cu30Al10Ni5 (a tungsten-particle-reinforced Zr-based bulk metallic glass composite) with a tungsten-particle volume fraction of 50% were prepared using spark plasma sintering (SPS). The average tungsten particle sizes were 30 & micro;m, 100 & micro;m and 200 & micro;m. The phase composition, microstructure and interfacial bonding of the prepared samples were characterised using X-ray diffraction (XRD), scanning electron microscopy(SEM), transmission electron microscopy (TEM) and energy-dispersive spectroscopy (EDS). Isothermal and non-isothermal crystallisation experiments were conducted on the Wp/Zr55Cu30Al10Ni5 amorphous composites using differential scanning calorimetry (DSC) to investigate the influence of the tungsten particle size on the crystallisation kinetics. The results indicated that the crystallisation kinetics of the three composites with different tungsten particle sizes were dependent on the heating rate. Moreover, tungsten particle size did not influence the crystallisation mechanism or the final crystalline products, which consistently consisted of Ni3Zr, CuAl2, and CuZr2 phases. As the particle size of tungsten increased, the interface area between tungsten particles and the amorphous matrix decreased, reducing the number of non-spontaneous nucleation sites. At the same time, the transition zone between tungsten particles and the amorphous matrix expanded, promoting crystalline nucleus formation. Consequently, the thermal stability analysis results exhibited a single peak characterised by an initial increase followed by a decrease. When the average tungsten particle size reached 100 & micro;m, the crystallisation activation energy (Ex) was 432.07 kJ/mol, representing optimum thermal stability. The thermal stability of the Wp/Zr55Cu30Al10Ni5 amorphous composites was governed by nucleation, diffusion and interfacial bonding.

This study aims to examine the impact damage mechanisms in tungsten particles reinforced Zirconium-based bulk metallic glass composites (Wp/Zr-BMGCs) and to clarify how variations in tungsten particle size influence their penetration and fragmentation behaviors. Penetration and post-impact damage performance of 50 % Wp/Zr-BMGCs by volume fraction into a 603 steel target plate is investigated experimentally. The results are subsequently compared with those of a 93 tungsten alloy (93 W). To investigate the penetration performance and damage ability behind the target composite materials, The damage effects of the 603 steel target plate and the after-effect target are analyzed. The results indicate that, in the initial penetration stage, Wp/Zr-BMGCs display a pronounced self-sharpening effect. This leads to a 4 %-11 % reduction in average crater diameter compared with 93 W. In the subsequent post-penetration stage, elevated temperatures weaken the interfacial bonding strength. Combined with Poisson's effect, this facilitates the formation of metallic fragment jets accompanied by intense energy-release reactions. The fragment jets reach a maximum dispersion angle of 65.6 degrees, a peak post-target hole expansion ratio of 47.1, and generate more than 120 effective perforations. For Wp/Zr-BMGCs, smaller particle sizes result in narrower diffusion layers between the reinforcing phase and the amorphous matrix, exhibiting enhanced penetration self-sharpening and superior post-penetration damage performance.

Under marine service environments, titanium is facing dual threats of corrosion and microbial contamination. In this study, a CeOx nanocluster-modified TiO2 is constructed on pure titanium via Micro-arc Oxidation technology with in-situ cerium salt introduction to control plasma discharge characteristics. It is found that the coating porosity with optimal Ce concentration is just 2.29%, and the thickness increases to 22.25 mu m. The electrochemical testing reveals that the coating's corrosion current density drops to 4.29 & times; 10-9 A/cm2, and the charge transfer resistance reaches 3.78 & times; 106 Omega center dot cm2, which still maintains a stable capacitive response after 14 days. This result is attributed to the combined effects of structural densification and electronic regulation at heterogeneous interfaces. Meanwhile, the antibacterial rates of the coating against Pseudomonas aeruginosa and Staphylococcus aureus reach 91.25% and 82.56%. According to experimental characterization and calculation of Density Functional Theory, it is confirmed that the Ce3+/Ce4+ redox pair not only drives redistribution of interface electrons, but also effectively reduces activation energy barrier of oxygen radicals, realizing efficient antibacterial activity through synergistic effect of the Cex+ ion release and accelerated generation of Reactive Oxygen Species. Hence, this study provides a theoretical basis for designing rare-earth-modified multifunctional marine protective coatings.

To improve the wear resistance of TA2 pure titanium, ceramic coatings were fabricated by micro-arc oxidation (MAO) in a silicate/phosphate (Si/P) electrolyte containing different concentrations of Na2MoO4. The effects of Na2MoO4 concentration on the phase composition, surface and cross-sectional morphology, mechanical properties, and wear resistance of the coatings were investigated. The results indicated that the addition of Na2MoO4 generated MoO3, which filled pores at the metal/oxide interface and enhanced coating compactness. The coating porosity decreased, while the mechanical properties, elastic modulus, and H/E ratio were enhanced. This led to increased resistance to crack damage, rendering the coating less susceptible to failure during the wear process. The coating wear rate decreased from 8.031 & times; 10-5 mm3/N & sdot;m without Na2MoO4 to 2.797 & times; 10-5 mm3/N & sdot;m with a Na2MoO4 concentration of 1.2 g/L. At an optimal Na2MoO4 concentration of 1.2 g/L, the coating exhibited the best structural compactness, enhanced load-bearing capacity, and reduced local stress concentration during the wear process. Consequently, the wear resistance was significantly improved. The wear process primarily involved micro-fracture spalling and abrasive wear.

In this study, the penetration capability and process of Tungsten-particle-reinforced Zr-based bulk-metallic-glass matrix composites (Wp/Zr-BMGCs) with different tungsten particle sizes at a volume fraction of 50 % were investigated through penetration experiments and numerical simulations. The mechanism of influence of the tungsten particles on the penetration behavior of the Zr-BMGCs was explored. The results demonstrated that adding tungsten particles enhanced the penetration capability of the Zr-BMGCs, with smaller particle sizes yielding stronger penetration capabilities. For the same type of composite, the duration of the stable penetration range was longer at high velocities compared to that at low velocities, thereby resulting in larger penetration depths but a slightly decreased penetration capability. In addition, tungsten particles hindered the propagation and merging of cracks during penetration, which reduced the mass and kinetic energy loss of the projectile, extending the duration of the stable penetration stage and enhancing the penetration capability of the projectile.

This study investigates the penetration behavior of 50 % vol. W-reinforced Zr-based bulk metallic glass composites (Wp/Zr-BMGCs) with W particle sizes of 30, 75, and 250 mu m using semi-infinite target penetration tests. The composites and craters were characterized via X-ray diffraction, optical microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The impact velocities during the tests were approximately 850 and 1250 m s-1. The results show that the penetration depth of the Wp/Zr-BMGCs at high impact velocities is greater than that at low impact velocities. At similar impact velocities, the smaller the particle sizes constituting the reinforcing phase, the greater the penetration depth. Among the composites, Wp/Zr-BMGC with a W particle size of 30 mu m achieves a maximum penetration depth of 10.62 mm at an impact velocity of 1283.8 m s-1. During penetration, the Zr-based amorphous phase melts and W particles primarily undergo plastic deformation. Adiabatic shear bands generated during penetration promote the nucleation and propagation of voids and cracks, resulting in target-plate damage. High-speed penetration-induced unloading waves generate coronal cracks near the bottom of the crater, accelerating target-plate damage. The good penetration capability of the Wp/Zr-based amorphous composite with 30-mu m W particles may be related to the beneficial effects of the small W particles on interfacial bonding.

High-performance batteries for military and extreme environment applications require alternatives to conventional liquid lithium-ion batteries (LIBs), which suffer from poor low-temperature performance and safety risks. All-solid-state lithium batteries (ASSLBs) offer enhanced safety and superior low-temperature capability. In this work, we designed and fabricated composite solid-state electrolytes using polyvinylidene fluoride (PVDF) and polyacrylic acid (PAA) as polymer matrices, N,N-dimethylformamide (DMF) as the solvent, and lithium bis(trifluoromethane sulfonimide) (LiTFSI) as the lithium salt. Composite solutions with varying PAA mass ratios were prepared. Advanced three-dimensional (3D) printing technology enabled the rapid and precise fabrication of electrolyte membranes. An ionic conductivity of about 2.71 × 10−4 S cm−1 at 25 °C, high mechanical strength, and good thermal properties can be achieved through component and 3D printing process optimization. Assembled LiCoO2||PVDF@PAA||Li ASSLBs delivered an initial discharge capacity of 165.3 mAh/g at 0.1 mA cm−2 (room temperature), maintaining 98% capacity retention after 300 cycles. At 0 °C, these cells provided 157.4 mAh/g initial capacity with 85% retention over 100 cycles at 0.1 mA cm−2. This work identifies the optimal PAA ratio for enhanced electrochemical performance and demonstrates the viability of 3D printing for advanced ASSLB manufacturing.

This study examines tungsten-particle (Wp) reinforced Zr-based bulk metallic glass composites (Wp/BMGCs) with 30 % and 50 % volume fractions, fabricated via Two-Step Spark Plasma Sintering (TSS) and Normal Spark Plasma Sintering (NS). The influence of the reinforcing phase particle size on the microstructure and mechanical properties of the material was systematically analyzed. The results reveal that reducing the Wp particle size from 200 mu m to 30 mu m profoundly influences the composite's interfacial and distribution effects, consequently altering its microstructure and mechanical properties. At higher Wp volume fractions, smaller particles tend to agglomerate, but increasing Wp particle size improves the reinforcement phase distribution. The densification of Wp/BMGCs is mainly influenced by interfacial effects, with smaller Wp particle sizes enhancing densification. TSS enhances interfacial bonding, further improving densification. Mechanical properties are primarily governed by interfacial effects in 30 % Wp/BMGCs and 50 % Wp/BMGCs prepared by NS, with smaller Wp particle sizes leading to enhanced properties. However, for 50 % Wp/BMGCs prepared by TSS, distribution effects dominate at smaller sizes, with TSS process exacerbates agglomeration, deteriorating mechanical performance. Micromechanical simulations show that Wp restricts shear band expansion and promotes cross proliferation, enhancing the material's overall mechanical performance.

W-particle-reinforced Zr-based amorphous composites (W-p/Zr55Cu30Al10Ni5) with a W-particle volume fraction of 50 % and W-particle sizes of 30, 75 and 250 mu m were prepared through spark plasma sintering. The effects of different W-particle sizes on the quasi-static and dynamic compressive behaviours of the composites were investigated using a scanning electron microscopy/energy-dispersive X-ray spectroscopy instrument, a universal testing machine and the split-Hopkinson pressure bar. The results showed that the addition of W particles considerably enhanced the strength and ductility of the amorphous composites. Under quasi-static compression, the compressive strength of the W-particle-reinforced Zr-based amorphous composites increased as the W-particle size decreased; the fracture strain also increased accordingly. At a W-particle size of 30 mu m, the composite achieved a maximum compressive strength of 1905 MPa and a maximum strain of 18.4 %. Under dynamic-compression conditions, the W-particle size was inversely proportional to the dynamic-compression strength of the material, with 3074 MPa obtained as the maximum strength. An analysis of the fracture morphology of the amorphous composites reveals that the fracture mode transitions from shear fracture to a mixed mode dominated by the W particles, a process involving interface debonding, cleavage fracture and ductile fracture.

In this paper, the high chromium cast iron（HCCI）hardfacing layer is deposited on the surface of D32 low-alloy steel by electroslag surfacing method. Combined with the temperature field measurement of the heat-affected zone（HAZ）during the surfacing process, the microstructure and mechanical properties of the HAZ, composite interface and hardfacing layer are studied. The results show that: the heating and cooling rates are slower during the electroslag surfacing, and the temperature distribution in the low alloy steel substrate during the stabilizing stage is uniform; the maximum temperature gradient in the surfacing direction is 23.1 ℃/mm. The maximum thermal stress in the low-alloy steel substrate is 25.9 MPa,lower than its tensile strength, which effectively avoids the occurrence of cracks; the composite interface is smooth and clear,with an austenite band region, about 50 μm in width; The grains of HAZ have grown, whose microstructure is a mixture of ferrite and pearlite. The microstructure of HCCI hardfacing layer is composed of austenite, carbides and a small amount of martensite. The M 7 C 3 type carbides are small and uniformly distributed in austenite grain boundaries. The bonding strength of the composite interface is 96 MPa; the impact energy （53J） of the composite sample is significantly higher than that of the HCCI hardfacing layer（10.7 J）. During abrasion, the HCCI hardfacing layer undergoes martensitic transformation under a large load, the hardness is improved, and an excellent performance in wear resistance was obtained.

The influence of W particles (Wp) addition on the crystallization behaviour was studied by comparing crystallization processes of Zr55Cu30Al10Ni5 amorphous alloy and Wp/Zr55Cu30Al10Ni5 amorphous composites by DSC, In-situ XRD and SEM/EDS. Results showed that Wp addition increased Tg, decreased Tx, Tp, and Delta T, resulting in a decrease in the thermal stability of the amorphous alloy. Wp could play a role of non-spontaneous nucleation and promoted the crystallization process. At the same time, Wp increased the internal viscosity, hindered the growth process of grains and led to a higher crystallization-activation energy. The nucleation growth process was mainly controlled by diffusion, and the nucleation rate decreased with increasing time. The crystallization products are primarily comprised the Zr2Cu phase, accompanied by a small amount of the Zr6Ni8Al15 phase as well as some unknown phases.

This study investigated the interfacial characteristics of tungsten-particle-reinforced Zr-based bulk-metallic-glass composites (Wp/Zr-BMGs) with varying tungsten-particle sizes. To this end, Wp/Zr-BMGs with three different Wp sizes were fabricated using spark plasma sintering. Subsequently, the microstructures and interfacial structures of the Wp/Zr-BMGs were extensively examined, and the mechanical properties of the microzone at the Wp/Zr-BMG interface were evaluated using a nanoindentation method. The results revealed that the interfaces of Wp/Zr-BMGs, irrespective of the Wp size, exhibited dissolution-diffusion characteristics. Moreover, the thickness of the interface diffusion layer was positively correlated to the size of Wp. The addition of Wp enhanced the elastic modulus and hardness of Zr-BMGs at the interface, as these effects are inversely related to the Wp size. Furthermore, this study established a relationship between the interfacial mechanical properties and the interfacial characteristics of particle-reinforced bulk-metallic-glass composites. Thus, this study can serve as a guide for future research in the field of Wp/Zr-BMGs and similar particle-reinforced composites.

为研究W颗粒/Zr41.2 Ti13.8 Cu12.5 Ni10 Be22.5基非晶复合材料在过冷液相区的塑性变形行为,利用同步热分析试验 、单轴压缩试验分析了温度和应变速率对该非晶复合材料塑性变形行为的具体影响,并采用X射线衍射(XRD)、显微硬度测试研究了塑性变形对该非晶复合材料结构和性能的影响.结果表明:该非晶复合材料在过冷液相区具有较好的塑性变形能力,随着温度的升高和应变速率的减小,其塑性流变应力不断减小,并逐渐呈现出均匀流变的特征;在温度为693 K、应变速率为1×10-3 s-1时,非晶复合材料流变应力为190 MPa,为该材料在过冷液相区的最佳成形条件;该非晶复合材料在变形后并未发生明显的晶化,由于自由体积减少,其显微硬度从512.2 HV增加到546.9 HV.

Tungsten-particle (Wp)-reinforced bulk-metallic-glass composites (Wp/BMGCs) with a Wp volume fraction of 0%–50% were prepared by spark plasma sintering (SPS). The sintering process parameters were optimized through an orthogonal experiment. With increasing volume fraction of Wp, the compressive yield strength of the Wp/BMGCs decreased, while their ultimate strength and plastic strain increased. Nanoindentation experiments revealed that the elastic modulus and hardness of the composites increased with increasing volume fraction of Wp. The elastic modulus mismatch between the tungsten particles and metallic glass matrix resulted in a stress concentration at the interface of the two phases, promoting the initiation and propagation of shear bands in the metallic glass matrix. Fracture morphology analysis of the composites showed that the failure mode of the composites was shear fracture mode, which is beneficial to the self-sharpening of the composites. With increasing volume fraction of Wp, the plastic deformation of Wp became more obvious, and the deformation was most obvious near the shear fracture surface. The degree of plastic deformation of Wp in the region far away from the shear fracture surface gradually decreased. In addition, the reliability of the mechanical properties of Wp/BMGCs sintered in the same preparation parameters was verified by three-parameter Weibull statistical analysis. These results help deepen our understanding of the preparation and mechanical properties of Wp/BMGCs and further promote their application.

微课与传统的课堂教学相结合,二者相互补充,促进了课堂教学方式的改进.微课在材料腐蚀与防护类课程教学中的应用,能有效地激发学生对该类课程的学习兴趣,活跃课堂气氛,提升学生的自主学习能力.利用微课将知识点碎片化,帮助学生对抽象知识的理解吸收.充分利用微课还可提高教学内容的实践性,培养学生解决问题的能力和实践动手能力.最终有效地提高教学质量.

The high-temperature deformation behavior of a Zr57Cu15.4Ni12.6Al10Nb5 bulk metallic glass (BMG) was studied by compression tests in the supercooled liquid region. Room temperature compression tests and microhardness tests were used to evaluate the effect of high-temperature deformation on room temperature service performance of the Zr-based BMG. The results show that the optimum processing parameters of the Zr-based BMG are 451 $$\pm$$ 5 °C and the strain rates range from 0.001 to 0.01 s−1. All the room temperature plastic deformation ratios of the Zr-based BMGs that have undergone high-temperature deformation at 451 °C increase with increasing strain rate and exceeds 5.5%, which is higher than that of ordinary as-cast Zr-based BMGs. Changes in the room-temperature service performance of the Zr-based BMG are attributed to the combined action of heat and force during high-temperature deformation in the supercooled liquid region. For Zr-based BMGs, a higher strain rate during high-temperature deformation is helpful to improve the room-temperature service performance under the premise of ensuring plastic formability.

通过电化学测试、浸泡实验以及表面分析,研究了50%体积含量的W颗粒/Zr 41.2 Ti 13.8 Cu 12.5 Ni 10 Be 22.5 基非晶复合材料在3%（质量分数） NaCl溶液中的腐蚀行为。结果表明:在3%NaCl溶液中,该复合材料表面由于W颗粒与非晶合金基体相的偶对效应而形成了局部腐蚀微电池,其中非晶基体部位作为局部阳极区其表面的腐蚀溶解加速,复合材料的腐蚀电流密度增大,其耐蚀性能明显低于Zr 41.2 Ti 13.8 Cu 12.5 Ni 10 Be 22.5 非晶合金。50%W颗粒的加入对该复合材料的耐点蚀性能基本没有影响,在3%NaCl溶液中基体非晶部位发生了均匀的腐蚀溶解,该非晶复合材料具有较好的耐点蚀性能。