钛及钛合金电弧钎焊及接头强度

用Ti—Cu—Ni，Ti-Cr-Zr钎料在TIG电弧加热条件对TA2和Ti—6Al—4V钛合金进行钎焊。结果表明：用Ti—Cu—Ni钎料钎焊TA2和Ti—6Al—4V钛合金的搭接接头强度分别是418．3MPa和439．6MPa；用Ti—Cr—Zr钎料钎焊TA2和Ti—6Al—4V钛合金的搭接接头强度分别是575．2MPa和656．1MPa。对Ti-Cu-Ni钎料／母材界面分析认为固液异分化合物η相((Cu，Ni)Ti2)生成时呈笋状生长，嵌入钎缝对钎缝的强度提高有利。对Ti-Cr-Zr钎料／母材界面分析，认为主要是固溶体β-Ti(Cr)存在提高了钎缝强度。     

High-Temperature Corrosion Resistance of Al–Re and Re Coatings

The oxidation behavior in air at 1473 K, and sulfidation behavior in a H2S–H2 gas mixture with a sulfur partial pressure of 10^–2 Pa at 973 K of Al–Re coated CMSX-4 were studied. Investigation on the sulfidation behavior of the Re-coated CMSX-4 was carried out in a H2S–H2 gas mixture with a sulfur partial pressure of 10^–2 Pa at 973 K. The experimental results show that a Re-rich alloy layer was formed between an -Al₂O₃ layer and the inner concentration zone of Ta and Ti for the CMSX-4 single crystal alloy with an Al–Re coating after oxidation. The Re-rich alloy layer containing Cr, W, Ni, Co, and Mo effectively inhibited the outward diffusion of alloying elements and the inward diffusion of Al. The Al/Re-coated CMSX-4 single crystal alloy had excellent sulfidation resistance; the Re-rich alloy layer, containing W, Ti, Ta, and Mo, which formed during the sulfidation process and located between the alumina scale and the CMSX-4 base alloy, plays a role in inhibiting the outward diffusion of alloying elements. The sulfidation resistance of CMSX-4 single-crystal alloy is greatly improved by a Re coating on the CMSX-4 alloy surface; this is attributed to a Re–Cr–W alloy layer that retarded the outward diffusion of cations and the oxide layer containing Ta, Ti, and Al, which inhibited the inward penetration of sulfur.     

Formation of nanostructured YSZ/Ni anode with pore channels by plasma spraying

YSZ/Ni is the conventionally most used material for making the anode of a solid oxide fuel cell. Agglomerated nanostructured YSZ/NiO powders and plasma spray are applied to produce nanostructured YSZ/NiO coatings on porous support substrates. After reduction in an ambient atmosphere of 7% hydrogen and 93% argon at about 800 °C for 4 hours, a novel SOFC anode with nanostructured characteristics such as nano YSZ particles, nano Ni particles, nano pores and nano pore channels is produced. This new YSZ/Ni anode provides larger triple phase boundaries for hydrogen oxidation reactions. X-ray diffraction patterns of these YSZ/NiO coatings after 1 h of heat treatment at temperatures from 700 to 1100 °C are obtained and Scherrer analysis is conducted to study the effect of temperature on grain size. The results obtained from SEM, TEM, XRD and EDX measurements and analyses are presented in this investigation.     

Boronitriding of Die Steels in Fluidized Bed

Processes of progressive and simultaneous boronitriding of die steels in fluidized bed are considered in comparison with conventional diffusion boronizing. A comparative analysis of the microhardness and wear resistance of die steels after boronitriding and boronizing is performed.     

激光焊接的模拟仿真研究

分析和总结了激光焊接仿真的研究现状，综述了模拟仿真过程中固液气之间的传热对流模型、激光和金属相互作用模型，激光在等离子体内的传播模型，以及材料热物理性能参数，金属材料的状态方程等问题的处理方法，并且列举了目前的成果，提出了未来研究的发展方向。     

Magnetic anisotropy of Co/Cu/Co nanocrystalline films upon magnetic annealing

The magnetic anisotropy of Co/Cu/Co films with the thickness of the copper spacer corresponding to the antiferromagnetic and ferromagnetic indirect exchange coupling between Co layers has been studied. The films deposited on naturally oxidized (111) Si single crystals were produced by magnetron sputtering. The films were annealed at 240°C. Such an annealing virtually neither changes the grain size nor leads to the mixing of layers; i.e., no disturbance of the coupling type between the cobalt layers takes place. Changes in the surface and induced magnetic anisotropy and in the effective energy of indirect exchange coupling have been studied upon annealing in the presence and absence of a magnetic field. It has been found that the shape of surface inhomogeneities in the films changes upon annealing in the magnetic field applied along the film plane, which substantially affects, the surface anisotropy. In the films characterized by antiferromagnetic coupling, the easy axis of magnetization is induced only in the magnetic fields exceeding the saturation field. The induced-anisotropy constant estimated theoretically agrees well with those determined experimentally.     

多侧孔零件冲孔模设计

介绍了一副典型的多侧孔冲孔模的设计分析和模具结构。由于多侧孔冲压件，大多数是侧孔布置在冲压件的周围，因而冲孔凹模只能放在冲压件的内部，往往受到冲压件体积的限制，这样冲孔凹模的强度和刚度都受到极大影响，该文介绍了两种方法解决这一问题，可供同行在类似产品设计中参考。     

Study On the Tribological Behavior of the Arc-added Glow Discharge Plasma Non-hydrogen Carburization On Titanium Alloy Surfaces

This paper introduces a new titanium alloys surface strengthening treatment by using the arc-added glow discharge plasmas non-hydrogen carburization technique. High purity and high strength graphite is selected as cooling cathode arc source for supplying carbon atoms and particle, which migrate to the titanium alloy(Ti6Al4V) surface and form modified layer. Thus, the hydrogen embrittlement is avoided while the tfibological behavior of the titanium alloy surface is improved in the respects of anti-friction and anti-wear ability.The tribological behavior of the modified layer under dry sliding against SAE52100 steel was evaluated on a ball-on-disc test rig. The results showed that the modified layer obtained a thickness of 30μm at 980℃, 30minutes. The microhardness of the Ti6Al4V alloy surface attained 936 HV, which was much larger than that of the Ti6AI4V alloy. The Ti6AI4V alloy was characterized by adhesion wear and scuffing under dry sliding against the steel, while the surface modified layer experienced much abated adhesion wear and scuffing under the same testing condition. This could be attributed to the carbon dement with different modalities exists in the modified layer.The modified layer showed good friction-reducing and fair anti-wear ability in dry sliding against the steel. Using the SEM,XRD and XPS, the phase structure and morphology of the carburization modified layer was analyzed.     

Macrosegregation in ESR and VAR Processes

The method of heat generation, heat transfer characteristics, and ingot structure are very different in the VAR and ESR processes, which result in different tendencies and mechanisms for macrosegregation formation in forged IN-718. Freckles are niobium rich and can be generated in both ESR and VAR, with higher incidence in ESR than VAR. White spots are niobium lean and can only be found in VAR-processed materials. Freckles are indige-nous in nature, and result from the flow of solute-rich interdendritic liquid in the mushy zone during solidification. The most plausible cause for white spots is exogenous material, which remains unmelted, falling into the molten pool. The best way to minimize the formation of freckles is to improve the ingot heat transfer rate, a more difficult task in ESR than in VAR.     

中频炉酸性炉衬使用寿命的探讨

通过对炉衬材料的选择,作用机理及影响石英砂炉衬材料寿命的相关因素的阐述,说明了SD-T-A石英砂干振料可提高中频炉酸性炉衬使用寿命的原因.