Ag-La2Sn2O7/SnO2电接触材料的抗电弧侵蚀特性研究

Anti-arc erosion properties of Ag-La2Sn2O7/SnO2 contacts

摘要:

本文采用化学共沉淀法合成了La2Sn2O7/SnO2复合粉体，并通过粉末冶金法制备了Ag-La2Sn2O7/SnO2电接触材料；研究了复合材料的抗电弧侵蚀性能，并对抗电弧侵蚀机理进行了探讨。结果表明：与Ag-SnO2相比，Ag-La2Sn2O7/SnO2电接触材料经电弧作用后表面形貌较为平整，表现出较低的熔焊力。这可能是由于在电弧作用下La2Sn2O7的存在有助于提高熔池的粘度，同时Ag-La2Sn2O7/SnO2触点表面分布的“小汗珠”状颗粒物能够起到分散电弧能量的作用，从而可以降低侵蚀区域的温升、减小熔焊力，表现出较好的抗熔焊性能。 Ag-La2Sn2O7/SnO2有望作为一种环保型电接触材料得到广泛应用。

Abstract:

La2Sn2O7/SnO2 composite powder was firstly synthesized by a low-cost co-precipitation, and Ag-La2Sn2O7/SnO2 electrical contact material was prepared by powder metallurgy method. Anti-arc erosion properties, mass loss and Vickers hardness of Ag-La2Sn2O7/SnO2 were investigated, and anti-arc erosion mechanism was discussed. Results show that the welding force of Ag-La2Sn2O7/SnO2 composite is much better than that of Ag-SnO2, which is because the new phase La2Sn2O7 can increase the viscosity of melt poor and improve wettability between silver and tin oxide to some extent. Meanwhile, Flatter arcing area and “beads-like” particles embedded scatteredly in the surface could decentralized arc energy by “Pinning Effect”, which can decrease temperature rise and lower welding force. Ag-La2Sn2O7/SnO2 composite could be a leading candidate material for electrical contacts in the future.