A Novel Method for the Preparation of Ag/SnO2 Electrical Contact Materials

摘要:

描述了一种制备Ag/SnO2电接触材料（SnO2的质量分数为12%）的新方法。首先采用共沉淀法制备Ag-SnO2纳米复合粉体（SnO2的质量分数为42%）并对该Ag-SnO2纳米复合粉体进行了表征。XRD结果表明制备的复合粉体由纯立方相的Ag和四方金红石相的SnO2组成；SEM及TEM结果表明，纳米SnO2与纳米Ag颗粒均匀弥散分布在复合粉体中；并借助于TG-DTA热分析对纳米复合粉体前驱体的制备过程进行了分析。然后，将Ag-SnO2纳米复合粉体与Ag粉混合，采用粉末冶金法制备成Ag/SnO2电接触材料，并对制备的Ag/SnO2电接触材料进行了表征。结果表明，由于纳米SnO2在Ag基体中弥散分布，制备的材料的物理性能如密度、硬度及电导率比普通工艺制备的材料好

Abstract:

A novel method was presented to prepare Ag/SnO2 (12 wt% SnO2) electrical contact materials. First, Ag-SnO2 nano composite powder with 42 wt% SnO2 synthesized by a coprecipitation method was characterized. XRD results reveal that the synthesized composite powder is composed of cubic Ag and rutile type of SnO2. SEM and TEM images show that nano-Ag and nano-SnO2 particles are homogeneously dispersed in the composite powder. The preparation process of nano composite powder was analyzed with the help of the TG-DTA curves of the precipitation. Then, the obtained Ag-SnO2 nano composite powder was mixed with Ag powder to prepare Ag/SnO2 electrical contact materials (ECM) by powder metallurgy process and the prepared Ag/SnO2 electrical contact materials was characterized. The results demonstrate that owing to the higher dispersion of nano SnO2 particles in Ag matrix, the physical properties of ECM prepared by the new method, such as the density, hardness and conductivity are better than that by the traditional method