摘要：The laser powder bed fusion(LPBF) process can integrally form geometrically complex and high-performance metallic parts that have attracted much interest,especially in the molds *** appearance of the LPBF makes it possible to design and produce complex conformal cooling channel systems in ***,LPBF-processed tool steels have attracted more and more *** complex thermal history in the LPBF process makes the microstructural characteristics and properties different from those of conventional manufactured tool *** paper provides an overview of LPBF-processed tool steels by describing the physical phenomena,the microstructural characteristics,and the mechanical/thermal properties,including tensile properties,wear resistance,and thermal *** microstructural characteristics are presented through a multiscale perspective,ranging from densification,meso-structure,microstructure,substructure in grains,to ***,a summary of tool steels and their challenges and outlooks are introduced.

摘要：A novel multicomponent high-Cr CoNi-based superalloy with superior comprehensive performance was prepared,and the evaluation of its high-temperature microstructural stability,oxidation resistance,and mechanical properties was conducted mainly using its cast polycrystalline *** results disclosed that the morphology of theγ′phase remained stable,and the coarsening rate was slow during the long-term aging at 900–1000℃.The activation energy forγ′precipitate coarsening of alloy 9CoNi-Cr was(402±51)kJ/mol,which is higher compared with those of CMSX-4 and some other Ni-based and Co-based ***,there was no indica-tion of the formation of topologically close-packed phases during this *** these factors demonstrated the superior microstructural stability of the *** mass gain of alloy 9CoNi-Cr was 0.6 mg/cm^(2) after oxidation at 1000℃ for 100 h,and the oxidation resistance was comparable to advanced Ni-based superalloys CMSX-4,which can be attributed to the formation of a continuous Al_(2)O_(3) protective ***,the compressive yield strength of this cast polycrystalline alloy at high temperatures is clearly higher than that of the conventional Ni-based cast superalloy and the compressive minimum creep rate at 950℃ is comparable to that of the conventional Ni-based cast superalloy,demonstrating the alloy’s good mechanical properties at high *** is partially because high Cr is bene-ficial in improving theγandγ′phase strengths of alloy 9CoNi-Cr.

摘要：Mg-Zn-Ca-Mn series alloys are developed as promising candidates of 5G communication devices with excellent thermal conductivities,great ductility,and acceptable *** present paper,Mg-x Zn-0.4Ca-0.2Mn(x=2wt%,4wt%,6wt%)alloys were prepared by a near-solidus extrusion and the effect of Zn content on mechanical and thermal properties were *** results showed that the addition of minor Ca led to the formation of Ca_(2)Mg_(6)Zn_(3) eutectic phase at grain boundaries.A type of bimodal microstructure occurred in the as-extruded alloys,where elongated coarse deformed grains were embedded in refined recrystallized grains ***,both yield strength and ductility of the alloys were significantly enhanced after extrusion due to the great grain ***,higher Zn content led to the increment in yield strength and a slight reduction in elongation due to the larger fractions of second phase *** room temperature thermal conductivity of as-extruded alloys was also improved compared with that of as-cast *** increment of Zn content decreased the thermal conductivity of both as-cast and as-extruded alloys,which was due to the increased second phase fraction and solution atoms in the matrix,that hindering the motion of *** as-extruded Mg-2Zn-0.4Ca-0.2Mn(wt%)alloy exhibited the highest elongation of 27.7% and thermal conductivity of 139.2 W/(m·K),combined with an acceptable ultimate tensile strength of 244.0 *** present paper provides scientific guidance for the preparation of lightweight materials with high ductility and high thermal conductivity.

摘要：The martensitic transformation,mechanical,and magnetic properties of the Ni_(2)Mn_(1.5-x)Cu_(x)Ti_(0.5) (x=0.125,0.25,0.375,0.5) and Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5)[(x=0.125,y=0.125,0.25,0.375,0.5) and (x=0.125,0.25,0.375,y=0.625)]alloys were systematically studied by the first-principles *** the formation energy,the martensite is smaller than the austenite,the Ni–(Co)–Mn–Cu–Ti alloys studied in this work can undergo martensitic *** austenite and non-modulated (NM) martensite always present antiferromagnetic state in the Ni_(2)Mn_(1.5-x)Cu_(x)Ti_(0.5) and Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5) (y<0.625) *** y=0.625 in the Ni_(2-y)Co_(y)Mn_(1.5-x)Cu_(x)Ti_(0.5) series,the austenite presents ferromagnetic state while the NM martensite shows antiferromagnetic *** doping can decrease the thermal hysteresis and anisotropy of the Ni–(Co)–Mn–Ti *** Mn and decreasing Ti content can improve the shear resistance and normal stress resistance,but reduce the toughness in the Ni–Mn–Cu–Ti *** the ductility of the Co–Cu co-doping alloy is inferior to that of the Ni–Mn–Cu–Ti and Ni–Co–Mn–Ti *** electronic density of states was studied to reveal the essence of the mechanical and magnetic properties.

摘要：With the increasing attention received by lightweight metals,numerous essential fields have increased requirements for mag-nesium(Mg)alloys with good room-temperature and high-temperature mechanical ***,the high-temperature mechanic-al properties of commonly used commercial Mg alloys,such as AZ91D,deteriorate considerably with increasing *** the past several decades,extensive efforts have been devoted to developing heat-resistant Mg *** approaches either inhibit the gen-eration of thermally unstable phases or promote the formation of thermally stable precipitates/phases in matrices through solid solution or precipitation *** this review,numerous studies are systematically introduced and *** alloy systems,includ-ing those based on Mg–Al,Mg–Zn,and Mg–rare earth,are carefully classified and compared to reveal their mechanical properties and strengthening *** emphasis,limitations,and future prospects of these heat-resistant Mg alloys are also pointed out and dis-cussed to develop heat-resistant Mg alloys and broaden their potential application areas in the future.

摘要：High-strength steels are mainly composed of medium-or low-temperature microstructures,such as bainite or martensite,with coherent transformation *** type of microstructure has a high density of dislocations and fine crystallographic structural units,which ease the coordinated matching of high strength,toughness,and ***,given its excellent welding perform-ance,high-strength steel has been widely used in major engineering constructions,such as pipelines,ships,and ***,visual-ization and digitization of the effective units of these coherent transformation structures using traditional methods(optical microscopy and scanning electron microscopy)is difficult due to their complex ***,the establishment of quantitative relationships with macroscopic mechanical properties and key process parameters presents additional *** article reviews the latest progress in microstructural visualization and digitization of high-strength steel,with a focus on the application of crystallographic methods in the development of high-strength steel plates and *** obtained the crystallographic data(Euler angle)of the transformed microstruc-tures through electron back-scattering diffraction and combined them with the calculation of inverse transformation from bainite or martensite to austenite to determine the reconstruction of high-temperature parent austenite and orientation relationship(OR)during con-tinuous cooling ***,visualization of crystallographic packets,blocks,and variants based on actual OR and digit-ization of various grain boundaries can be effectively completed to establish quantitative relationships with alloy composition and key process parameters,thereby providing reverse design guidance for the development of high-strength steel.

摘要：The optimization of the scaffolds to provide a suitable matrix and accelerate the regeneration process is vital for bone tissue ***,poor mechanical and biological characteristics remain the primary challenges that must be *** example,although bredigite(Br)has shown great potential for application in bone tissue engineering,it easily fails in *** the present work,these challenges are addressed by reinforcing the Br matrix with nanosheets of graphene oxide(rGO)that have been reduced by bovine serum albumin(BSA)in order to enhance the mechanical properties and biological *** reduction of graphene oxide by BSA improves the water stability of the nanosheets and provides an electrostatic interaction between theBSA-rGO nanosheets and theBr *** high thermal conductivity of theBSA-rGO nanosheets decreases the porosity of the Br by transferring heat to the core of the ***,the addition of BSA-rGO nanosheets into the Br matrix enhances the adhesion of G-292 cells on the surface of the *** findings suggest that the tablet consisting of BSA-rGO-reinforced Br has encouraging potential for application in bone tissue engineering.

摘要：This study reviews the state of the art in structural design and the corresponding mechanical behaviours of composite vascular grafts. We critically analyse surface and matrix designs composed of layered, embedded, and hybrid structures along the radial and longitudinal directions;materials and manufacturing techniques, such as tissue engineering and the use of textiles or their combinations;and the corresponding mechanical behaviours of composite vascular grafts in terms of their physical–mechanical properties, especially their stress–strain relationships and elastic recovery. The role of computational studies is discussed with respect to optimizing the geometrics designs and the corresponding mechanical behaviours to satisfy specialized applications, such as those for the aorta and its subparts. Natural and synthetic endothelial materials yield improvements in the mechanical and biological compliance of composite graft surfaces with host arteries. Moreover,the diameter, wall thickness, stiffness, compliance, tensile strength, elasticity, and burst strength of the graft matrix are determined depending on the application and the patient. For composite vascular grafts, hybrid architectures are recommended featuring multiple layers, dimensions, and materials to achieve the desired optimal flexibility and function for complying with user-specific requirements. Rapidly emerging artificial intelligence and big data techniques for diagnostics and the threedimensional(3D) manufacturing of vascular grafts will likely yield highly compliant, subject-specific, long-lasting, and economical vascular grafts in the near-future.

摘要：Designing strong, yet ductile, and body-centered cubic(BCC) medium-entropy alloys(MEAs) remains to be a challenge *** this study, the strength–ductility trade-off of Ni_(0.6)CoFe_(1.4)MEAs was tackled via introducing a BCC + face-centered cubic(FCC) dual-phase microstructure. Ni_(0.6)CoFe_(1.4)Nbx(x = 0, 0.05, 0.08, 0.10, and 0.15, in molar ratio) MEAs were prepared using vacuum induction melting. Results show that the new alloy is composed of BCC plus FCC dual phases featuring a network-like structure, and the BCC phase is the main phase in this alloy system. Moreover, the Nb0.10 MEA shows high strength and respectable tensile ductility, representing the best combination of the strength and fracture elongation among the alloys studied here. The remarkable strength of the Nb0.10 MEA is attributed to the combined effect of the solid solution strengthening, the precipitation hardening effect and the interface strengthening effect.

摘要：本文设计并制造了一种能够制备高质量非晶复合材料条带的新型配有水冷铜板的双辊铸轧原型机.利用该轧机在不同温度下成功制备了具有三种不同体积分数β-Ti枝晶的非晶复合材料带材(简称BT30,BT48和BT60),并通过一系列三点弯曲试验研究了其力学性能.结果表明,在高温下轧制的带材,高温元素在中间区域富集,导致成分分布不均.此外,由于铸轧过程中热力耦合导致在非晶复合材料中存在较大的内应力,这会显著影响其力学性能.新型铸轧设备为制备非晶复合材料带材提供了新的途径,基于该设备进行的研究深化了对非晶复合材料带材微观组织及力学性能的理解.