热挤压工艺对反应合成AgSnO_2材料显微组织的影响  

Effect of Hot Extrusion on Microstructure of AgSnO_2 Prepared by Reaction Synthesis Processing

作　　者：张昆华[1] 孙加林 管伟明 卢峰 陈敬超[2] 杜焰[2] 周晓龙[2] 陈松 

机构地区：[1]贵研铂业股份有限公司,云南昆明650221 [2]昆明理工大学,云南昆明650093

出　　处：《贵金属》2005年第4期1-5,共5页Precious Metals

基　　金：国家科技攻关(2001BA326C);云南省科技攻关(2000B-03)联合资助项目

摘　　要：采用反应合成和热挤压方法制备出新型AgSnO2电接触材料。利用金相显微镜和扫描电镜研究了反应合成法制备的AgSnO2材料热挤压前后的显微组织,分析了挤压速度、挤压模具等工艺条件对AgSnO2挤压线坯显微组织的影响,计算了采用平模挤压和45°锥模挤压的等效应力分布值,探讨了锥模挤压改善AgSnO2加工性能的机理。发现快速挤压使AgSnO2锭坯产生严重的径向不均匀变形,导致SnO2沿径向不均匀分布;而慢速挤压得到较均匀分布的SnO2,有利于AgSnO2力学性能的提高。研究还发现采用45°锥形模挤压,出模口应力梯度较小,有利于改善AgSnO2丝材的后续加工性能。在本研究的基础上,得到比较合理的AgSnO2挤压工艺。A new type of AgSnO2 contact material was fabricated by reaction synthesis and hot extrusion processing. Microstructure of the AgSnO2 materials before and after hot extrusion were studied by metallurgical microscope and scanning-electron microscope （SEM）, The effects of extrusion speed and extrusion die on microstructure of AgSnO2 wires were analyzed, the equivalent stress distributions with level extrusion die and 45° taper die were calculated, respectively, the mechanism of workability improvement of AgSnO2 was discussed. It was found that the fast extrusion made uneven distribution of SnO2 in AgSnO2 along the radial direction, however, the slow extrusion got evenly distributed SnO2 in AgSnO2, helping raise the mechanical properties of AgSnO2. It was also found that using the 45° taper die, the stress gradient at the die outlet was small, benefiting improvement of workability of AgSnO2 wires. Based on the above investigation, a reasonable extrusion process was established.

关 键 词：复合材料 银二氧化锡电接触材料 反应合成法 热挤压 显微组织 

分 类 号：TG146.32[一般工业技术—材料科学与工程]