Research On The Forming Of Copper-Graphite-SiC Composite

ABSTRACT:Copper-Graphite-SiC is a new composite with excellent comprehensive performance which contains self-lubricating, high abrasion resistance and high conductivity, and its application field is very extensive. In order to develop the Copper-Graphite-SiC composites with excellent performance, this paper carried out the research on the forming mode of this composite. On account of the existing high cost of forming technology, complicated process problem, uneven organization, this research uses the semi-solid casting as the preparation method of Copper-Graphite-SiC. First, it uses mechanical stirring with double blade to prepare semi-solid slurry in which all particles are well-distributed, then it uses conventional casting to prepare Copper-Graphite-SiC in which raphite and SiC are well-distributed. The main research and results are as follows:(1) Using mechanical stirring with single blade to prepare Copper-Graphite-SiC semi-solid slurry, study the relationship between the blade angle γ and distributions of graphite and SiC particles. Experimental studies show that when the γ=30°, only graphite particles can be well-distributed. It indicates the stirring intensity of the mechanical stirring with single blade is not enough to make SiC particles distribute well.(2) Using mechanical stirring with double blade to prepare Copper-Graphite-SiC semi-solidslurry, study the relationship between the blade spacing of layer h and distributions of SiC particles. Experimental studies show that when h=10-20mm, SiC particles can be well-distributed. It indicates the mechanical stirring with double blade can prepare the Copper-Graphite-SiC semi-so lid in which both graphite and SiC particles are well-distributed.(3) Making Copper-Graphite-SiC semi-solid slurry, establishing the relationship model between solid rate and the mixing temperature.(4) Conducting conventional casting of Copper-Graphite-SiC semi-solid slurry, preparing Copper-Graphite-SiC composite materials. Establishing the relationship model between solid rate and graphite and SiC particles in ingot, determine the realization of graphite and SiC particles evenly distributed in the ingot casting conditions:solid rate greater than20%.