Study On Preparation And Deformed Microstructure And Properties Of Cr₂O₃/Cu Composites

Copper matrix composites reinforced with oxide particles have been widely used as electrode material, contact material, integrated circuit lead frame material, and so on, which have high strength, high electrical conductivity and excellent heat resistance properties. In this paper, Cr₂O₃/Cu composites were prepared by the combination methods of MA and IN-SITU. In order to optimize processing parameters, various factors which affect the preparation of Cr₂O₃/Cu composites have been studied. The influences of hot extrusion on the microstructure and properties of Cr₂O₃/Cu composites, and the effects of Cu-Cr powders characteristic on oxygen diffusion have also been investigated .The results show that:(1) While Cr₂O₃/Cu composites were prepared by the combination methods of MA and IN-SITU, the optimal processing parameters were as following: the rotate speed of the ball milling is 200rpm, the ball-milling time is 72hrs, the mass ratio of balls to powders is 20:1, the samples were pressed along two direction, the pressure is 400-500MPa, the sintering temperature and the sintering time are 950℃ and 2hrs respectively.(2) The two-direction pressing is more optimal than the single-direction one. The tightness, electrical conductivity and hardness of Cr₂O₃/Cu composites formed by two-direction pressing are better than those of the single-direction one.(3) When the sintering temperature was in the range of 850-1015℃, the tightness and electrical conductivity increased with the increase of temperature. The hardness increased with increase of temperature before 950℃, but the hardness decreased above 950℃. When the sintering time was in the range of 1-3hrs, the tightness, electrical conductivity and hardness of Cr₂O₃/Cu composites reached maximum at 2hrs.(4) The hot extrusion deformation improved the properties of Cr₂O₃/Cu composites...