Research On Preparation Technology And The Friction And Wear Properties Of The Bronze-copper Coated Graphite Composite

Duo to the excellent mechanical properties, good wear resistance, high electrical and thermal conductivity, copper matrix composites are widely applied in machinery, electron and aerospace field etc. Graphite possesses many superior properties, such as high wear resistance, excellent thermal conductivity as well as low coefficient of thermal expansion (CTE). It is strongly expected that superior copper matrix composites will be attained by dispersing graphite into the copper matrix homogeneously.In this paper, the research progress of graphite reinforced copper matrix composites at home and abroad was reviewed, the problems of fabricating graphite reinforced copper matrix composites were analyzed, copper-graphite composites were fabricated by powder metallurgy in this paper. The effect of ball mill processing is molding, sintering temperature and time etc. on the micro structure and properties of the composite materials is studied in this paper and the optimum process conditions of preparation of composite materials is determined.The density, hardness, tensile property and abrasive resistance of the copper matrix with different graphite content has been tested, and observing and analyzing the microphotograph of the composite through by SEM and metallographic microscope. Results show that:with the increase of graphite content of bronze-copper coated graphite, the density and hardness of the composites is reduced, and its friction and wear properties are improved significantly. the friction coefficient and wear rate of bronze-copper coated graphite composite decreases first, then increases with the increase of wear rate, but increases as the load increases. As wear rate is low, the wear is medium when mechanical gearing and abrasive wear plays a leading role; As speed is medium, mild adhesive wear play main role; As speed is high, the wear is serious when corrosion wear and fatigue wear play main role; In addition, the wear mechanism has been analyzed by observing the morphology of the wear surface and the wear debris.