摘要：Biomedical metals are widely used as implant materials in the human or animal body to repair organs and restore function, such as heart valves, meninges, peritoneum and artificial *** element affects the microstructure, mechanical property, corrosion resistance and wear resistance, but also influences the antibacterial and biological ***, antibacterial metal alloys have shown great potential as a new kind of biomedical materials, in which Cu has been widely used as antibacterial agent *** addition, biodegradable metal alloys, including magnesium alloy and zinc alloy, also have attracted much attention *** was also used as alloying element to adjust the degradation ***, the role of Cu in the alloy design will be very important for the development of new *** this paper, we summarized the recent research results on the Cu-containing metal alloy for biomedical application and hoped that this review would give more suggestions for the further development of biomedical metal alloy.

摘要：The hypoeutectic Al-Si alloy billet with non-dendrite was reheated to meet the needs of the semi-solid thixoforming microstructure by four kinds of reheating power,achieving the same final temperature of 851 ***,under the same condition of thixoforming,the microstructure,surface hardness and tensile properties were ***,quantitative analysis was made for the microstructures of the reheated semi-solid of billet and the thixoforming *** results show that when the induction reheating power is 90 kW,the average grain size of the semi-solid billet is the minimum,the microstructures of the thixoforming samples also are the finest,and the mechanical properties of the relevant thixoforming samples are the ***,after studying on the relationship between the microstructures of the semi-solid billet of aluminum alloy and the mechanical properties of the thixoforming samples,the reverse design of microstructure is primarily ***,the effectiveness of the reverse design for semi-solid microstructure is confirmed by an actual automobile part with complex shape.

摘要：This paper presents the findings of an experimental investigation into the effects of cutting speed, feed rate, depth of cut and approach angle in turning of titanium (Grade 5) alloy. A two-level factorial experiment has been used to accomplish the objective of the experimental study. The main cutting force, i.e. tangential force (Fc) and surface roughness (Ra) were the response variables investigated. The experimental results indicate that the proposed mathematical models suggested could adequately describe the performance indicators within the limits of the factors that are being investigated. The feed, cutting speed and depth of cut is the most significant factor that influences the surface roughness and the tangential force. However, there are other factors that provide secondary contributions to the performance indicators.

摘要：Phase field models were established to simulate the grain growth of a nanostructured AZ31 magnesium alloy,which contain spherical particles of differing sizes and volume fractions, under realistic spatial and temporal *** effect of the second phase particles on the nanostructure evolution was studied. The simulated results were compared with those of the conventional microstructured *** expression of the local free energy density was improved by adding a second phase particle term. The right input parameters were selected for proper physical meaning. It was shown that the rules that govern the pinning effect of the second phase particles during the grain growth were different for the nanostructure and microstructure. There was a critical particle size value that affected the grain growth within the nanostructure. If the particle size was lower than the critical value, the pinning effect on grain growth increased with decreasing particle size. When the particle size was greater than the critical value, the particles had almost no pinning ***, in the conventional microstructured material,the larger particle size resulted in an enhanced pinning effect during grain growth for particle sizes smaller than 1 μm. The effect was reversed when the particle size was larger than the critical value. For the nanostructure, the critical value was200 nm when the particle content was 10 v.%, and the critical value decreased when the content increased. When the particle size was 30 nm, the particle pinning effect on the grain growth increased for increasing particle content.

摘要：Zinc-aluminum alloys have been used as bearing materials in the past. In recent years, binary Al-Zn alloys and Al-Zn-Cu alloys are being used as an alternative to the Zn-Al alloys for bearing applications. In this study, both binary Al-25 Zn and Al-3 Cu were prepared using stir casting process. Homogenization of the as-cast alloys was performed at 350oC for 8 h and then, the alloys were furnace-cooled to 50oC. The homogenization led to the removal of the dendritic structure of the as-cast alloys. After homogenization, wear parameters optimization was carried out using Taguchi technique. For this purpose, L9 orthogonal array was selected, and the control parameters selected are load, velocity, and sliding distance. The optimum parametric condition was obtained using signal-to-noise(S/N) ratio analysis, and specific wear rate(SWR) is the selected response. The "smaller-the-better" is the goal of the experiment for S/N ratio analysis. After the optimization, confirmation tests were carried out using analysis of variance(ANOVA) from the developed regression equation. Finally, wear mechanism studies were conducted using scanning electron microscopy(SEM) and energy-dispersive X-ray spectroscopy(EDX) images.

摘要：Fishes interact with the fluid environment using various *** multiple control surfaces work in combination to produce the thrust and the balance torques in a steady swimming,to maneuver and to position themselves accurately even in turbulent *** motivate us to embark on a research program designed to develop an agile biologically inspired robotic fish based on the performance of multiple *** accomplish this goal,a mechanical ray-like fin actuated by the shape memory alloy (SMA) is developed,which can realize the oscillating motion,the undulating motion or even the complex three dimensional *** basic unit is the two opposite side SMA-driven plate,namely the fin *** a result,a lightweight bio-inspired fin is constructed by placing radially multiple SMA fin rays.A biologically inspired underwater vehicle (BIUV) is later built using the above multiple lightweight bio-inspired *** common arrangement styles of multiple fins on the BIUV are considered here:one is the posterior fin (for the oscillating motion) that is parallel to the anterior fins (for the undulating motion),another one is the posterior fin that perpendicular to the anterior *** kinematic modeling,the deformation modeling and the detecting of the SMA fin are *** thrust generation is also ***,an experiment is conducted to test the performance of the proposed two arrangement styles,including the comparison of the averaged propulsion velocity and the averaged thrust under certain kinematic ***,the influence of the frequency and the amplitude of the SMA fin ray on the propulsion performance is also investigated.

摘要：A novel Ni-Cr-Si-B filler metal with the cluster formula of[Cr-Ni12]B2Cr+[B-Ni8Cr]BSi Cr based on the cluster-plus-glue-atom model was designed for vacuum brazing GH4169 *** effect of brazing temperature and brazing time on microstructure and shear strength of GH4169 alloy joints was *** brazed seam was mainly composed ofγ-Ni solid solution.(Nb,Ti)-rich phase and(Cr,Nb,Mo)-rich borides distributed in diffusion *** diffusion and aggregation of B,Cr,Nb,and Mo resulted in the variation of phase contrast and morphology of *** precipitations in the joint brazed at1240℃consisted of borides,Laves phase andδ*** shear strength of joints was principally dominated by the brittle precipitations in diffusion zone,and the homogenization of microstructure improved the room-temperature shear strength to 820 MPa with the high-temperature shear strength of 627 MPa for the joint brazed at 1240℃/20 *** joint fractured in diffusion zone and brazed seam,and the existence of borides and Laves phase in diffusion zone provide the potential origin for crack growth.

摘要：A high Si reduced activation ferritic/martensitic(RAFM) steel for nuclear structure application is successfully designed by using Calphad method. The main designed chemical composition is C 0.18–0.22%, Cr10.0–10.5%, W 1.0–1.5%, Si 1.0–1.3%, V+Ta 0.30–0.45%, and Fe in balance. High Si design brings excellent corrosion resistance, while low activation is advantageous in the nuclear waste processing. The experimental results indicate that the newly designed high Si RAFM steel had full martensitic structure and uniformly distributed fine second phase particles, and exhibited excellent mechanical properties and corrosion resistance. Compared to the P91 steel, this new RAFM steel designed by Calphad method is expected to be a promising candidate used in nuclear power generation, which also provides a new and effective approach to the development of RAFM steel for nuclear application.

摘要：Using density functional theory （DFT） calculations, we rationally designed metallic nanocatalysts with ternary transition metals for oxygen reduction reactions （ORRs） in fuel cell applications. We surrounded binary core-shell nanoparticles with a Pt skin layer. To overcome surface segregation of the core 3-d transition metal, we identified the binary alloy Cu0.76Ni0.24 as having strongly attractive atomic interactions by computationally screening 158 different alloy configurations using energy convex hull theory. The PtskinCu0.76Ni0.24 nanoparticle showed better electrochemical stability than pure Pt nanoparticles -3 nm in size. We propose that the underlying mechanism originates from favorable compressive strain on Pt for ORR catalysis and atomic interactions among the nanoparticle shells for electrochemical stability. Our results will contribute to accurate identification and innovative design of promising nanomaterials for renewable energy systems.

摘要：Near net-shape production of complex parts with higher mechanical properties is one of the most important final goals of the recent researches on the semi-solid *** the knowledge of the influence of every parameter on the properties of final parts is the key in the production of high quality complex *** these parameters forming temperature and velocity,and reheating and holding times have the greatest effects on the final mechanical properties of the *** influence of the parameters of non-dendritic billet production,forming speed,temperature and holding time on the properties of semi-solid extruded parts were ***-slope method was employed in order to produce non-dendritic *** material used was A356 aluminum *** the number of the parameters influencing the final properties of the parts was high(these parameters include:cooling slope angle,ram velocity,temperature and holding time),the final number of the experiments required would be n4,in which n is the number of the states of the parameters(5 in our case).In order to reduce this amount,design of experiments Tachuchi method was employed(design L25).Using this method the number of required experiments was reduced to *** the experiments the prepared semi-solid samples were extruded under isothermal condition and with 5 different ram *** tensile tests were conducted on the extruded parts and the mechanical properties of the parts were *** obtained results analyzed with MiniTab and the influence of each of the parameters and also the percentage of its influence were *** an optimum region for the parameters was *** temperature,ram speed,slope angle and holding time have more important effects descendingly.