Abstract: Based on analyzing the results from the temperature field model of the electrical contacts,the status changes of the electrical contact materials and the evolution of geometrical profile of weld pool after arcing were described in detail.The characteristics of the solidification process were summarized and their great effects on the microstructure and composition of the electrical contact materials were discussed as well.The results show that the cooling rate in the solidification process after arcing duration was as fast as 107 ℃·s-1.The especially distinct characters in the solidification process of weld pool in electrical contacts include easy nucleating,a high gradient of temperature,vary fast cooling rate,porous structure and chemical reactions and so on.