Air arc erosion behavior of CuZr/Zn₂SnO₄ electrical contact materials

Cu-based composites are considered as one of the high performance and cost-effective materials to replace the noble metal-based electrical contact materials used in low-voltage electrical apparatus. However, the oxidation resistance of Cu-based electrical contact materials at high temperatures is still the major challenge that limits their applications. In this study, CuZr/Zn₂SnO₄ composites were prepared through powder metallurgy method. The air arc erosion resistance of the composites under AC 380 V and 20 A was evaluated through the mass loss and the electrical contact resistance after experienced over 10,000 arc discharge cycles. The microstructure evolution, which reflected the deterioration process of the composites, was demonstrated through SEM analysis. The results indicated that the oxidation of Zr occurred along with the oxidation of Cu at high temperature, which considerably consumed the oxygen and thus significantly enhanced the oxidation resistance of Cu-based composites. In addition, TEM result showed a smooth and clear interface between Cu and Zn₂SnO₄ phases, suggesting that the addition of Zn₂SnO₄ phases was beneficial to enhance the durability of the composite. This work will not only merit the design and development of Cu-based electrical contact materials but also expand the applications of Cu-based composites in the air at high temperature.