Influence of Rare Earth on the Wetting Ability of AgSnO2 Contact Material

摘要:

AgSnO2是最有可能替代AgCdO的触头材料，但AgSnO2在使用过程中存在先天的缺陷。添加稀土元素能否增大AgSnO2触头材料的润湿性，改善其缺陷是本文讨论的重点。通过杨氏方程可知，润湿角θ越小，材料的润湿性越好。本工作选取La和Ce两种稀土元素，选取与SnO2的3种不同配比制备触头材料，利用座滴法测量了银基触头材料的润湿角。再与AgSnO2触头材料的润湿角进行对比。从测量结果可知，La元素对AgSnO2触头材料润湿性的改善效果明显。为了进一步验证这一结论，对AgSnO2和AgSnO2La2O3两种触头材料进行了模拟电弧试验，并对其进行微观分析。从而证明了AgSnO2La2O3触头材料的润湿效果较好。

Abstract:

AgSnO2 is a most potential substitute contact material for AgCdO. In practice, however, it has some congenital defects. This paper, is to focus whether wetting ability of AgSnO2 contact material can be improved and its defects can be decreased when rare earth elements are added. Young’s equation has proved that the smaller the wetting angle is, the better the material wetting ability. So, rare earth elements La and Ce were selected as additives in the present experiment. And three Ag-based contact materials were prepared with different ratios of SnO2 to La or Ce. Then, wetting angles of the contact material were measured by the sessile drop method. They were compared with the wetting angle of the AgSnO2 contact material. The measurement results show that La can improve the wetting ability of AgSnO2 contact material obviously. For further proving this conclusion, the simulation arc tests for AgSnO2 and AgSnO2La2O3 contact materials were carried on. And their microstructures were analyzed. The results prove that AgSnO2La2O3 contact material has better wetting ability than AgSnO2.