不同种类稳定剂对化学镀Ni-P性能的影响

在合理选择化学镀Ni-P合金配方和工艺条件的基础上,研究了稳定剂KI、Pb（Ac）2和Na2S2O3对化学镀Ni-P合金镀液的稳定性、镀速以及镀层硬度、孔隙率、耐蚀性能等的影响。结果表明：KI的最佳加入量为8mg/L,稳定剂Pb（Ac）2在用量为1mg/L效果也较好,而Na2S2O3浓度应小于2mg/L,但是稳定剂KI的综合效果要优于Pb（Ac）2、Na2S2O3。     

Microstructural evolution and mechanical properties of Nb-Si-Cr ternary alloys with a tri-phase Nb/Nb5Si3/Cr2Nb microstructure fabricated by spark plasma sintering

In this work, pure Nb, Nb₅Si₃ and Laves Cr₂Nb compound powders were used as raw materials to prepare Nb-Si-Cr ternary alloys by spark plasma sintering (SPS). A comprehensive estimation of the microstructure and properties, including room temperature fracture toughness, high temperature strength and oxidation resistance, of the Nb-Si-Cr ternary alloys as a function of the Nb/Nb₅Si₃/Cr₂Nb phase volume fraction combinations was conducted. The results showed that Nb-Si-Cr ternary samples with the relative density larger than 98.42% were obtained by SPS processing, and the samples all consisted of Nb, Nb₅Si₃ and Cr₂Nb phases that were distributed homogeneously. The fracture toughness K_Q of the Nb/Nb₅Si₃/Cr₂Nb microstructure, which was dominated by the Nb phase, naturally increased with the Nb fraction. As expected, the room-temperature Vickers hardness and the high-temperature strength of the bulk alloys increased monotonically with the increasing of the stiffening Nb₅Si₃ fraction. Interestingly, the binary Cr₂Nb phase played a positive role in the high temperature strength and oxidation resistance. Finally, the fracture modes of the typical Nb/Nb₅Si₃/Cr₂Nb microstructures under bending and compression conditions at room and high temperatures as well as the oxidation mechanism are described and discussed.     

Strategies for improving ductility of ordered intermetallics

Ordered intermetallics possess attractive high-temperature properties; however, low ductility and brittle fracture limit their use as engineering materials in many cases. This paper provides a comprehensive review on the recent progress in the development of ductile ordered intermetallics and summarizes the strategies used to improve the tensile ductility of ordered intermetallics, including control of ordered crystal structures, engineering grain-boundary structure and chemistry, eliminating environmental embrittlement, microstructure optimization, control of phase stability, and promoting transformation-/twining-induced plasticity. The basic ideas and related mechanisms underlying these ductilizing strategies are discussed. In addition, a brief mention of the current use of intermetallic alloys for structural and corrosion applications is made.     

小AI-Ni合金团簇的结构

本文选用了基于紧束缚模型的Gupta多体势，采用遗传算法研究了团簇的原子数目为13和19以及21的Al—Ni混合团基的基态构形。将Al团簇中的一个或多个Al原子替换成Ni原子，Aln团簇的基态构形转化为象Ni团蔟一样规则的，具有高对称性的结构。当替换的Ni原子数目增加时，混合团簇会形成一些复杂结构。     

锌铁合金蓝白钝化液的研究

研究三价铬蓝白钝化液中配位剂的作用及其用量对钝化效果的影响,得到最佳的配位剂的配比及用量。对在最佳配比和用量条件下得到的钝化层进行耐蚀性检测后,得出满意的结果并符合工业生产的要求。     

工作液电导率对高Nb-TiAl合金电火花加工小孔精度影响

采用PAAS（聚丙烯酸钠）的水溶液作为电火花小孔加工工作液,研究了工作液电导率对高Nb-TiAl合金(Ti-44Al-8.5Nb-0.2Mo-0.2B)电火花加工小孔孔径精度、孔口微观形貌的影响规律,结果表明,随着电导率增大,其中的载流子数量将不断增多,在放电和电解溶解的共同作用下,小孔放电间隙迅速增大,小孔精度下降,此时放电间隙增大幅度不足以快速排除电蚀产物,电蚀产物在冷却的孔壁上再凝固,重铸层厚度快速增加。电导率增长后期,击穿电压不断下降,电解作用减弱,工作介质流动交换充足,电蚀产物快速排除,放电间隙和再铸层厚度增长速度均减慢。     

镍钛合金加强梁的有限元法

就含镍钛合金丝的梁的静力及动力问题，描述了镍钛合金丝与玻璃纤维树脂基体的相互作用，进行了镍钛合金丝和加强梁受温度、外载作用下力学行为的分析，并给出形状记忆合金复合材料的有限元分析方法     

采用CaO精炼获得高纯金属及合金的进展

本分析了使用CaO坩埚进行精炼的机制；列举了CaO坩埚精炼过程在电子学、超导母合金等领域的一些成功的例子；总结了在先进结构材料（包括航空和航海仪器铸件、用于航空发动机上的高温合金铸件）方面的应用；展望了CaO坩埚精炼的前景。总之，CaO坩埚精炼在高纯金属及合金的发展方面具有良好的应用前景。     

01420Al-Li合金超塑性研究

采用单向拉伸对01420Al-Li合金进行超塑性研究。发现该合金经过适当的机械热处理后能获得良好的超塑性．显微组织观察表明，经过双级时效处理的01420Al-Li合金，基体内弥散分布大量的大颗粒S相粒子，在大压下率横轧后，经再结晶退火后获得稳定的、等轴的细晶组织，因而超塑效应显著．细小而分散的空洞是得到超塑性的必需的组织成分．     

用喇曼光谱研究半导体带隙和合金组分

阐述了从喇曼光谱测量三元化合物半导体的双模频移和双模强度比率来确定含金组分。提出了由共振喇曼散射研究半导体的能带结构。实验观测了半导体 GaP在间接带隙(Γ_8?—Χ_(3c))附近的2TA和2TO双声子共振特性。实验表明共振喇曼散射可以测定半导体的直接带隙和间接带隙。