制备工艺对Ag/SnO_2材料力学性能的影响

Influence of Fabricated Process on the Mechanical Properties of Ag/SnO_2 Materials

采用粉末冶金和反应合成两种工艺制备了Ag/SnO2电接触材料,分析了两种工艺对显微组织的影响,发现反应合成法制备的Ag/SnO2材料经热挤压后,SnO2颗粒呈纤维状排列,颗粒细小,分散均匀,与基体浸润良好。断裂拉伸测试和分析表明,粉末冶金法制备的Ag/SnO2材料的拉伸断口形貌由许多互相连接的撕裂棱和韧窝组成,表现为韧断;而反应合成法制备的断口形貌韧窝更加细小,显示出近脆性断裂特征。最后比较了两种方法制备的Ag/SnO2材料的抗拉强度、延伸率、硬度等力学性能。

Silver tin oxide(Ag/SnO_2) materials which fabricated by powder metallurgy and reactive synthesis methods were researched,and the influence of the two processes on microstructure was analyzed.By hot extrusion deformation,the tin oxide particles which were fabricated by reactive synthesis method present fiber microstructure,and the particles were finer,dispersing homogenously,contacting with matrix of silver firmly.The SEM fractographs of the powder metallurgy specimens indicate that the fracture morphology consists of many coadjacent tearing mountain ranges and tough nests.Whereas the tough nests of reactive synthesis fracture morphology appear more finer,and present the character of tough fracture.The mechanical performance such as the tensile strength,percentage elongation,hardness of Ag/SnO_2 material fabricated by two methods are compared finally.