Temperature Dependencies of the Tribological Properties of Copper-Molybdenum Binary Oxide Powders

摘要

Aluminum bronze coated with MoO_3 powder was rubbed against stainless steel in our previous work and it was suggested that copper molybdate was generated on the friction track at high temperature and acted as high temperature lubricant. Thus, in order to investigate the lubricity of copper molybdate powders, the lubricating properties of MoO_3, CuO and two kinds of copper molybdate (Cu_3Mo_2O_9 and CuMoO_4) powders supplied to the sliding interface of stainless steel specimens were studied under various temperature conditions up to 700°C. Copper molybdate powders were synthesized by heating the mixture of MoO_3 and CuO powders in air under certain temperature conditions. Both of Cu_3Mo_2O_9 and CuMoO_4 powders showed lower friction coefficient with increasing of ambient temperature. On the other hand, at high temperatures, MoO_3 and CuO powders showed poor lubricity and they showed higher wear amount of stainless steel specimens comparing with two types of copper molybdate powders. It was suggested that the good adhesiveness of copper molybdate powder on the stainless steel at high temperature could be one of the reasons of excellent lubricating properties of them.