Study On Microstructure And Properties Of SiCp/Cu Composites

SiC particles reinforced copper matrix composites, with the volume fraction of 50%, 55% and 60%, were fabricated by squeeze-casting technique for electronic packaging applications. The microstructures of SiCp/Cu composite were studied by using optical microscope, scanning electron microscope and transmission electron microscope. The physical and mechanical properties of SiCp/Cu composite were analyzed by means of analytical balance, thermal dilatometer, thermal conductivity tester, electrical resistance tester and three-point bending tests, also with their influencing factors discussed.The SiCp/Cu composite with high densifications can be produced by squeeze-casting technique, and the densification of SiCp/Cu composite with particle volume fraction of 55% reaches 97.8%, which is higher than the same materials reported in-country. The microstructures of SiCp/Cu composite are dense and uniform. TEM observations indicate high-density dislocations are found in the matrices of composites and the stacking faults in the SiC particles. The SiC-Cu interfaces exists interface reactions. And the analysis shows SiC particles decompose into carbon and silicon under high temperature, and the latter dissolves into the matrix Copper to form a new CuSi solid solution, the carbon precipitates into Copper and forms conglomerations with particle shapes.In the paper, the average CTEs of SiCp/Cu composite with volume fraction of 50% gets 8.54×10-6/℃, that can meet the usage properties of electronic packaging materials. The CTEs of SiCp/Cu composite decrease with the SiC particles'volume fraction, and after annealing the CTEs of SiCp/Cu composite are lower than that as cast. The thermal conductivities and electronic conductivities of SiCp/Cu composites decrease with the particles'volume fraction. Annealing treatment has little effect on thermal conductivity of composites.The mechanical properties of composites are superior. With the increasing of the SiC particles'volume fraction, the elastic modulus increase step by step except the SiCp/Cu composite with volume fraction of 60% because of it's bad densification, but the three-point bending and Fracture toughness strength decreasing. After annealing, the mechanical properties of composites decreases...