AgNi10触头材料分离阶段的热-电-力耦合分析及实验研究

Finite Element Analysis and Experimental Study on the Thermal-Electric-Mechanical Coupling of AgNi10 Electrical Contactor during the Breaking Process

建立了基于AgNi10电接触材料的直流分离过程的热-电-力耦合的有限元模型,计算考虑了材料物理特性随温度的变化、相变问题以及符合实际工作环境的边界条件等,通过实验的方法测定了接触电阻以及动触头的分离加速度并应用到了模型中,通过合并节点的方式解决了分离过程中接触半径的变化,分析了分离过程中接触区域温度场、电势场的变化特点,得出了不同电流负载条件下分离过程形成的熔池的相关参数。结果表明:在5～25A,10CN,154.32μm/ms2的负载条件下,接触区域出现熔池即熔化区域的接触电压为0.38V;焦耳热源仍为"环形热源",且随着接触半径的减小而增大;在约29μs的时间形成熔池,在电流负载为5,15,25A时,熔池宽度分别为6.90,10.5,14.04μm,而且计算结果与实验结果基本吻合。

The finite element thermal-electric-mechanical coupling model of AgNi10（wt%） during the direct current single breaking process was established.The variation of physical and mechanical properties with temperature was taken into account.Phase change and real boundary condition were also considered.The contact resistance and the accelerated speed of the moving contact were tested through experiments and applied to the model.The variation of contacting radius was solved by combining the nodes.Parameters of forming the melting pools during the breaking process at different currents were obtained by analyzing the variational features of temperatures and potential fields.The results show that under the loading condition of 5～25 A,10 CN and 154.32 μm/ms2,the contact electric pressure is 0.38 V in the melting pool of the contact area;the joule heat resource is a ring one,which increases with the decrease of the contact radius;the melting pool is formed in about 29 μs,the width of which is 6.90,10.5 and 14.04 μm under the current of 5,15 and 25 A,respectively and the calculated result is basically accordant with the experimental one.