合金化对还原罐用耐热钢力学性能的强化

对炼镁还原罐用低Ni型和高Ni型耐热钢进行多元合金化设计,试样的显微组织和力学性能检测结果表明:Mo、W、Nb、V等元素可形成碳、氮化合物并弥散分布于基体中,有效地提高了耐热钢室温和高温强度,同时较高的Ni含量对于减少高温δ相数量起到有益作用。通过对化学成分的计算和分析表明,高Ni型耐热钢对防止有害σ相的产生起到抑制作用。     

Effect of surface modification of metal hydride electrode on performance of MH/Ni batteries

A novel method was applied to the surface modification of the metal hydride(MH)electrode of MH/Ni batteries.Both sides of the electrode were plated with a thin silver film about 0.1μm thick using vacuum evaporation plating technology,and the effect of the electrode on the performance of MH/Ni batteries was examined.It is found that the surface modification can enhance the electrode conductivity and decrease the battery ohimic resistance.After surface modification,the discharge capacity at 5C(7.5A)is increased by 212 mA.h and the discharge voltage is increased by 0.11 V,the resistance of the batteries is also decreased by 32%.The batteries with modified electrode exhibit satisfactory durability.The remaining capacity of the modified batteries is 89%of the initial capacity even after 500 cycles.The inner pressure of the batteries during overcharging is lowered and the charging efficiency of the batteries is improved.     

金属塑性成形有限元六面体网格自动划分

六面体网格具有计算精度高、网格数量少等特点 ,是工程三维有限元分析一种重要网格。本文提出了一种基于栅格的六面体网格自动划分方法 ,它首先采用栅格法生成核心网格 ,然后把核心网格与模型边界拟合 ,为克服由于边界拟合造成的表面网格质量下降 ,采用包络表面网格的方法生成零厚度表层网格 ,通过表面网格平滑和内部节点位置平滑处理 ,最终生成具有较高质量的全六面体网格。网格划分实例说明 :该法具有原理简单 ,算法可靠 ,编程方便 ,划分网格质量高等特点。最后还对该算法进行了讨论。     

CRYSTALLOGRAPHIC ANALYSIS OF THE LATH MARTENSITE TRANSFORMATION IN Fe-Ni-Mn ALLOY

1.IntroductionBased on the concept of an invariant plane strain (IPS), phenomenological theory of martensite transformation (PTMT) is established[1-3]. In this case, an invariant plane is obtained by self-accommoda-tion effect between different martensitic variants, and the formula which reveals this self-accommoda-tion effect can be written as …     

Gas barrier properties and periodically fractured surface of thin DLC films coated on flexible polymer substrates

Thin DLC films coated on polymer surfaces are attracting considerable attention due to their wide applications and their interesting surface properties. When DLC films were coated on polymers, the resulting DLC-polymer composites are highly functionalized materials, some of which presenting dramatically improved gas barrier properties.In this paper, we will introduce several commonly used polymers including polyethylene terephthalate (PET), polyethylene (PE) and polypropylene (PP) for semi-crystalline polymers, and polymethyl methacyrlate (PMMA) for an amorphous polymer. The polymers were coated with thin DLC films and the gas barrier properties of the resulting DLC-polymer composites were investigated. Some of the DLC-polymer composites dramatically improved their gas barrier properties while they presented horizontal crack lines and vertical micro-buckling lines on the DLC surface when stretched to a certain strain. The gas barrier properties of the DLC-polymer composites with fractured DLC surface were also studied. It was found that the gas barrier property of the polymer substrates with lower residual strains was less damaged, when the substrates were mechanically deformed, than that of the polymer substrates with higher residual strains. When the number of the cracks increases, the strain imposed on each crack decreases, since the overall deformation is almost equally distributed to each crack while the crack spacing of each crack becomes shorter. Thus, it was found that the degradation of the gas barrier property after mechanical deformation is dependent on the residual strain of the polymers and the number of cracks on DLC films.     

蓝宝石晶片纳米级超光滑表面加工技术研究

本文提出以蓝宝石塑性磨削和化学机械抛光为主要手段，以原子力显微镜为主要检测工具，来制备满足光电子领域要求的纳米级超光滑蓝宝石晶片的新方法。在高刚性磨床上，用W7的金刚石砂轮以f=1μm／r进给量，实现了蓝宝石晶片的浅损伤塑性域磨削。配制了以SiO2溶胶为抛光料的监宝石晶片专用抛光液，稳定地获得了无损伤层的RMS小于0.2nm的超光滑蓝宝石晶片表面。GaN外延生长所需蓝宝石晶片的合理抛光参数是：SiO2的粒子直径为7nm、浓度为3％、pH=11、压力P=200Pa。     

烧结NdFeB磁体热浸镀锌工艺研究

研究了在烧结钕铁硼表面热浸镀锌的工艺，结果发现在烧结钕铁硼表面和镀覆材料之间形成了冶金结合，但镀层和烧结钕铁硼基体之间有环形裂纹出现，其原因是由于钕铁硼磁体的膨胀特性造成的。     

6×××系汽车车身板铝合金的合金化及组织性能的研究

采用力学性能试验和光学金相分析法,研究了Mg和Mn等元素对6×××系汽车板铝合金组织及性能的影响。结果表明:Mg和Mn是提高6×××系汽车板铝合金时效初期硬化值的元素,但对时效初期硬化速度影响不大。提高Mg和Mn含量,合金经170℃30min时效后的强度增大,伸长率降低。合金固溶处理淬火后的晶粒尺寸和形态不随Mg含量而改变,但随Mn含量增加而显著细化。     

超声深滚对TC4钛合金表面形貌和表面粗糙度的影响

研究了采用超声深滚处理（UDR）对钛合金（TC4）试件表面形貌和表面粗糙度的影响.采用扫描电子显微镜观察分析了超声深滚处理前后的试件表面形貌,采用表面粗糙度仪分析研究了强化处理前后的表面粗糙度变化.结果表明,超声深滚处理可以显著降低机加工痕迹,消除表面微损伤,大幅降低表面粗糙度,可使表面粗糙度由Ra 2.32 m降低到Ra 0.11 m.