| Because La2O3 has hexagonal structure system and the effect on the properties of composites from the unique outer cell electron structure, the application of La2O3 in tribology has drawn attention. In this paper, powder metallurgy has been used to make Cu-based composites with different addition of La2O3 and graphite in high pure argon. The effect of La2O3 and graphite addition on the mechanical, physical and friction and wear properties of Cu-based composites were studied and analyzed.The results showed that there was no chemical reaction during sintering, and three phases kept their original properties. And with the increasing of La2O3 addition and decreasing of graphite addition, the density, hardness, flexural strength and electrical resistivity all increased, while the relative density decreased.The electrical wear experiment shows that with the increasing of La2O3 addition and decreasing of graphite addition, the contact voltage drop and friction coefficient both increased. The contact voltage drop and friction coefficient maintained smooth with the increasing of sliding time. The composite which had 3vol% La2O3 and 37vol% graphite possessed the lowest wear rate and the best wear resistance.Three composites containing Ovol% La2O3,3vol% La2O3,7vol% La2O3 were used to test the mechanical wear properties in different temperature. The results showed that the wear rate of composite containing 3vol% La23 was about 1/2 of the wear rate of composite which had no La2O3 addition in room temperature. However the wear rate of the composite containing 3vol% La2O3 tested in 400℃ was only 1/3 of the wear rate of composite which had no La2O3 addition, which meant the effect of La2O3 on the wear resistance was more prominent in high temperature compared with room temperature. |
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