Effect of La2Sn2O7 content on the anti-arc erosion capability of Ag-Ni-La2Sn2O7 composites

La 2 Sn 2 O 7 has high melting point and excellent thermal stability, which improves the wettability between matrix and reinforcement. In this study, La 2 Sn 2 O 7 powder was synthesized by chemical coprecipitation method, and Ag-Ni-La 2 Sn 2 O 7 composites were prepared by vacuum hot-pressing sintering. The effect of La 2 Sn 2 O 7 content on the arc erosion behavior of Ag-Ni-La 2 Sn 2 O 7 composites was studied. The Ag-Ni-La 2 Sn 2 O 7 (85:12:3) composite has the lowest arc energy and the highest breakdown strength . With the increase of La 2 Sn 2 O 7 content, the defects on the cathode surface decrease and the erosion areas become flat. After arc erosion, the samples generate Ag 2 O, NiO, La 2 O 3 and SnO 2 . In this study, the mechanism of La 2 Sn 2 O 7 to improve the anti-arc erosion capability of composites is mainly enhancing the viscosity of the molten pool by the ``pinning'' action, consuming energy by the decomposition of La 2 Sn 2 O 7 , and the promotion of arc movement.