纯银触头熔桥行为高速摄像研究

采用自主设计的电接触-高速摄像试验系统,在直流单分断模式下对纯银触头在电接触过程中所发生的熔桥行为进行观测,从而在不同的电流条件下对电接触过程中熔桥的形貌尺寸进行研究,同时通过SEM对电接触熔桥行为作用后纯银触头的表面进行形貌分析。结果表明,在DC 10 V(8~20 A)条件下,纯银触头在电接触过程中形成的熔桥有圆柱型和哑铃型2种形貌,并且其尺寸为微米级;熔桥的直径和长度都随电流的增大而呈现出先减小后增大的趋势,10~15 A范围内纯银触头在电接触过程中不易形成熔桥,电接触过程中电弧可能先于熔桥而产生,并且熔桥和电弧现象可以同时存在。

High Speed Imaging Observation on Molten Bridge of Ag Electrical Contact

Under the DC and break only operation mode, the molten bridge phenomena of Ag electrical contact material was investigated by the electrical contact-high speed imaging experimental system by own making. The dimension of molten bridge was measured along with measurement of SEM morphology on contacts surface after the behavior of electrical contact. Results showed that the shape of molten bridge which generates during electrical contact process had two types which are the cylindrical and dumbbell, and the dimension of molten bridge was micron level under the condition of DC 10 V (8~20 A). The diameter and length of molten bridge both decrease with the increase of current and then increase with the increase of current. It is difficult to form molten bridge in the electrical contact process of Ag contacts in the range of 10~15 A. It can be observed that arc may occur before the appearance molten bridge, molten bridge and arc can exist at the same time.