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 ,...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。展开更多
Due to their outstanding electrical contact properties,Cd-containing silver-matrix electrical contact materials can meet the requirements of high stability and long life for military defense and aerospace applications...Due to their outstanding electrical contact properties,Cd-containing silver-matrix electrical contact materials can meet the requirements of high stability and long life for military defense and aerospace applications.In order to further reduce the Cd content under the premise of meeting the high-performance requirements,in this study,high-purity intermediate Ti_(2)Cd powder of MAX phase(Ti_(2)CdC)was synthesized with a pressureless technique and then applied to reinforce the Ag matrix.The Cd content of the as-prepared Ag/Ti_(2)Cd composites was actually reduced by 38.31%compared with conventional Ag/CdO material.Based on the systematic study of the effect of heat treatment temperature on the physical phase,morphology,interface and comprehensive physical properties of Ag/Ti_(2)Cd composites,the preferred samples(heat treated at 400°C for 1 h)showed high density(97.77%),low resistivity(2.34μΩ·cm),moderate hardness(90.8HV),high tensile strength(189.9 MPa),and exhibited good electrical contact performance after 40000 cycles of arc discharging under severe conditions(DC 28 V/20 A).The results of microscopic morphological evolution,phase change and elemental distribution of the electrical contact surface show that the combination of high stability of Ti_(2)Cd reinforcing phase,good interfacial bonding with Ag matrix and improved melt pool viscosity in the primary stage of arc erosion,results in low and stable contact resistance(average value 13.20 mΩ)and welding force(average value 0.6 N),low fluctuation of static force(2.2-2.5 N).The decomposition and absorption energy of Ti_(2)Cd and the arc extinguishing effect of Cd vapor are the main reasons for the stable arcing energy and arcing time of electric contacts in the late stage of arc erosion.展开更多
文摘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。
基金This work was financially supported by the National Natural Science Foundation of China(52101064)Jiangsu Planned Projects for Postdoctoral Research Funds(2020Z158)Industry-University-Research Cooperation Projects(RH2000002728,RH2000002332,RH2100000263).
文摘Due to their outstanding electrical contact properties,Cd-containing silver-matrix electrical contact materials can meet the requirements of high stability and long life for military defense and aerospace applications.In order to further reduce the Cd content under the premise of meeting the high-performance requirements,in this study,high-purity intermediate Ti_(2)Cd powder of MAX phase(Ti_(2)CdC)was synthesized with a pressureless technique and then applied to reinforce the Ag matrix.The Cd content of the as-prepared Ag/Ti_(2)Cd composites was actually reduced by 38.31%compared with conventional Ag/CdO material.Based on the systematic study of the effect of heat treatment temperature on the physical phase,morphology,interface and comprehensive physical properties of Ag/Ti_(2)Cd composites,the preferred samples(heat treated at 400°C for 1 h)showed high density(97.77%),low resistivity(2.34μΩ·cm),moderate hardness(90.8HV),high tensile strength(189.9 MPa),and exhibited good electrical contact performance after 40000 cycles of arc discharging under severe conditions(DC 28 V/20 A).The results of microscopic morphological evolution,phase change and elemental distribution of the electrical contact surface show that the combination of high stability of Ti_(2)Cd reinforcing phase,good interfacial bonding with Ag matrix and improved melt pool viscosity in the primary stage of arc erosion,results in low and stable contact resistance(average value 13.20 mΩ)and welding force(average value 0.6 N),low fluctuation of static force(2.2-2.5 N).The decomposition and absorption energy of Ti_(2)Cd and the arc extinguishing effect of Cd vapor are the main reasons for the stable arcing energy and arcing time of electric contacts in the late stage of arc erosion.
