制造非晶硅锗合金膜的新技术

本文报告了我们设计的制造非晶硅锗合金膜的一种新方法——直流反应溅射法。用这种方法,我们得到了锗含量从5％到95％的分布均匀的氢化非晶硅锗合金,膜质均匀、致密,是制造太阳能电池、锗化锗晶体管的优良材料。     

增强镁合金耐磨性研究方法的总结

镁合金是目前实际生产应用中最轻的金属材料,具有密度小,比强度和比刚度高,阻尼性、切削加工性和铸造性能好等优点。因此,镁合金产品越来越多的用于汽车、通讯和航天工业中。     

多次冲击载荷作用下典型铝合金材料动态响应规律

为了研究典型铝合金材料在多次冲击载荷下的响应规律,基于落锤冲击试验机进行了7075-T7351铝合金试样多次冲击试验,采用控制变量法研究冲击能量、冲击次数以及缺口对材料冲击性能的影响.通过分析多次冲击过程中载荷、吸收功、塑性变形以及冲断次数的变化规律,研究了材料在多次冲击载荷下的冲击响应.结果表明:7075-T7351铝合金多次冲击过程中硬化现象明显,冲击次数、冲击能量以及缺口等对材料的冲击性能有重要影响.     

铝合金活塞材料的研发与应用进展

活塞作为汽车发动机中传递能量的一个非常重要的构件,对其材料具有特殊的要求：密度小、质量轻、热传导性好、热膨胀系数小;并要求具有足够的耐高温、耐磨和耐蚀性能及尺寸稳定性好的特性．在传统的铸造铝硅活塞合金的成分优化和处理工艺的研究还没有大突破的情况下,科研工作者已经在寻求新的途径提高铸造铝合金的极限强度．通过采用基体增强和新型活塞成型工艺,显著提高了活塞的性能．随着汽车发动机向高速化、大功率方向的发展,新型铸造铝合金活塞复合材料及短周期的压力成型技术的开发应用都将成为一个发展趋势．     

高强压铸铝合金抗腐蚀性能的研究

在相同试验条件下,在腐蚀液酸、碱、盐等介质中,做了浸渍腐蚀、晶间腐蚀等对比试验,并测定了恒电位极化曲线。结果表明,高强压铸铝合金比一般铝硅合金具有较好的抗腐蚀性能,从试验和理论上验证了铝硅合金在高速冷却下凝固时,提高含铜量并不降低其抗腐蚀性能。     

2-(5-溴-2′-噻唑偶氮)-5-二甲氨基苯甲酸合成及其与镍的分光光度研究

本文合成了2-(5-溴-2′-噻唑偶氮)-5-二甲氨基苯甲酸、研究了它的性能及其与Ni(Ⅱ)的反应条件,在pH4.0～4.8范围,Ni(Ⅱ)与试剂形成蓝色络合物,组成比为1:1,表观摩尔吸光系数为8.7×10~4Lmol~(-1)cm~(-1),用拟定的方法测定了合金钢中微量镍,所得结果与标准样相符。     

Influence of composition and size on the thermodynamic stability and structural evolution of CuAlNi nanoclusters

The heating process for CuAlNi nanoclusters with cuboctahedral structure was studied by molecular dynamics simulation with the embedded atom method. A diffusionless martensitic transformation from the cuboctahedral (CO) to the icosahedral (ICO) structure before the melting point was found in some CuAlNi nanoclusters. The effects of element composition and cluster size on the thermodynamic stability and structural transformation of trimetallic nanoclusters were investigated. The results show that the CO–ICO transformation temperature was size-dependent and occurred only for small clusters. It was also observed that the CO–ICO transformation temperature firstly dropped and then raised as Al concentration increased, which may be strongly related to the release of excess energy. Furthermore, the surface segregation phenomenon was also observed that the lower surface energy components, such as Al and Cu atoms, segregated to the surface of CuAlNi nanoclusters. The changes in the melting points of CuAlNi nanoclusters with different alloy compositions and cluster sizes were also studied. And furthermore, the physical basis of structural transition of CuAlNi nanoclusters was discussed.