CuW和CuMo触头在DC 200～500V时不同气氛中表面劣化研究

Study on surface degradation of CuW and CuMo contacts in different atmospheres at DC 200-500V

触头的劣化程度与触头材料、环境气氛种类、触头的闭合速度及关合压力等许多因素有关。本文利用触点模拟装置,在直流电压200~500V,阻性负载电流40~150A,环境气氛为Air、N2、CO2、O2、Ar、0.5CO2+0.5Ar条件下对CuW70与CuMo85触头开展实验研究,用扫描电镜和x射线能谱仪观察了上述实验后的部分CuW70、CuMo85触头表面,分析了各气氛中触头的电弧侵蚀形貌特征及其形成原因,不同气氛中表面劣化规律的研究对于新型触头材料的开发与电器可靠性的提高具有重要意义。结果表明CO2条件下触头表面变形面积最小,N2、Ar中触头表面较平整,不同气氛中阳极触头表面产生裂纹的数量从多到少排序为:CO2>Air>O2>Ar>N2>0.5CO2+0.5Ar,N2、Ar中阴极触头表面出现大面积Cu富集现象。

The degree of deterioration of the contacts is related to many factors such as the contact material,the type of ambient atmosphere,the closing speed of the contacts,and the closing pressure.Experiments are conducted with the CuW70 and CuMo85 contact material under DC supply voltage 200-500V and resistive load current 40-150A and surrounding atmospheres Air,N2,CO2,O2,Ar and 0.5CO2+0.5Ar respectively.The surface of CuW70 and CuMo85 contacts after the above experiments are observed by scanning electron microscopy and x-ray energy spectrometer.The arc erosion morphology of the contacts in each atmosphere and its formation are analyzed.The study of surface degradation in different atmospheres is of great significance to the development of new contact materials and the improvement of electrical reliability.The results show that the surface deformation area of the con-tact is the smallest under CO2 conditions,and the contact surface is relatively flat in N2 and Ar.The number of cracks on the surface of the anode contact in different atmospheres is ranked as follows:CO2>Air>O2>Ar>N2>0.5CO2+0.5Ar.Large-area Cu enrichment occurs on the surface of the cathode contact in N2 and Ar.