反应合成AgSnO_2电接触材料的组织与性能研究

Investigation in Properties and Microstructure of Silver-Tin Oxide Electrical Contact Materials Fabricated by Reactive Synthesis

采用反应合成技术和传统粉末冶金技术制备银氧化锡 (Ag Sn O2 )电接触材料。利用千瓦 CO2 激光器模仿电弧作用在试样表面产生局部熔化 ,对 Ag Sn O2 块体材料进行抗熔蚀性测试。对 Ag Sn O2 块体材料进行电导率测试和 X射线衍射分析 ,对块体材料及冷拉拔的 Ag Sn O2 线材进行显微组织分析 (扫描电镜、透射电镜 )。研究结果表明 ,采用反应合成技术可以在银基体中合成尺寸细小、界面新鲜的 Sn O2 颗粒 ,所制备的 Ag Sn O2 电接触材料中 ,微米级的 Sn O2 颗粒系由纳米级的 Sn O2 颗粒聚集而成 ;反应合成法制备的 Ag Sn O2 电接触材料较传统粉末冶金法制备的 Ag Sn O2 电接触材料具有更高的导电性和抗熔蚀性 ;该方法制备的 Ag Sn O2 电接触材料由于改变了 Ag、Sn O2 的结合状态使材料的加工性能。

Silver-tin oxide (AgSnO 2) were fabricated both in conventional powder metallurgy (PM) and reactive synthesis (RS) method. The local melt on AgSnO 2 sintered body surface was carried out by CO 2 Laser to simulate the current arc, and the erosion resistance analysis was done to bulk AgSnO 2. The conductivity and X-ray diffraction analysis were done to bulk AgSnO 2, and the microstructure of bulk AgSnO 2 and cold drawn wire were determined through scanning electron microscope (SEM) and transmission electron microscope (TEM). The results shown that SnO 2 particles with finer size, fresh interface can be formed in silver matrix, and then the AgSnO 2 electrical contact materials can be fabricated by reactive synthesis. The tin oxide particles in micrometer dimension were assembled from nanometer particles in RS process. Compared with conventional PM process, the AgSnO 2 electrical contact materials fabricated by RS process have a higher conductivity. For the reason that the combination state of silver and tin oxide had been changed, the working properties, conductivity and erosion resistance were enhanced in AgSnO 2 electrical contact materials fabricated by RS process.