Study Of β-SiC Plating And The Microstructures And Properties Of Copper Matrix Composites

Metal and ceramic each have distinct characteristics, the mixture of the two may produce complementary advantages and disadvantages balance, homogeneous m aterials can not have a single overall excellent performance. SiC/Cu composites whi ch combine Cu excellent conductivity, thermal conductivity with SiC high strength, high wear resistance performance were concerned about by more and more people f or its outstanding performance. β-SiC and Cu metal belong to the cubic system, an d the lattice constant close. The compound of β-SiC and Cu laid the foundation for high quality metal matrix composites, but the difference between the β-Si C and C u wettability, weak bonding strength and nanometer β-SiC powder andwhiskers une venly distributed in Cu matrix, partial reunion phenomenon, these issu-es which will cause the instability of composites have become the main obstacle to the productio n of high quality β-SiC/Cu composites.In this study, the method of electroless plating copper film was used on β-SiC micron powder(β-SiCp), nanometer powder(nano β-SiCp) and whisker(β-SiCw) to change its wettability with Cu. β-SiCp/Cu composites and β-SiC(w+p)/Cu hybrid composites were prepared by hot pressing tech-nology. The organizational structure of the composite powders after copper plating was discussed. The effect of hot pressing parameters(the sintering temperature, sintering pressure) on organizational structure and thermal expansion properties of β-SiCp/Cu composites. The effect of different volume fraction of β-SiC micro powder on organizational structure, thermal expansion properties and wear resistance of β-SiCp/Cu composites. The effect of different volume fraction of β-SiC whisker on organizational structure, thermal expansion properties and wear resistance of β-SiC(w+p)/Cu hybrid composites with a certain volume fraction of β-SiC nanopowder.The results showed that: Using electroless plating may be copper plating on the surface of β-SiCp, nano β-SiCp and β-SiCw. Cu film was uniform and compact, no nudity and the surface was rough, composed of many different sizes of nano crystalline Cu which size was about 150 ~400nm. The growth pattern of the Cu film was island growth.The phase compositions of β-SiCp/Cu composites were Cu, β-SiC and α-SiC. β-SiCp were uniformly in the matrix, angular, no significant agglomeration, there was a good interface between β-SiC and Cu matrix. The relative density of β-Si Cp/Cu composites became gradually larger with the rising of sintering temperature and sintering pressure, and became reduced with the increase of the volume fraction of micro β-SiC. The coefficient of thermal expansion increased with the rising of temperature, sintering temperature,sintering pressure and the volume fraction of micro β-SiC. The friction coefficient of the composites decreased gradually with the rising of volume fraction of micro β-SiC, the wearability was getting better and better.The basically same phase compositions of β-SiC(w+p)/Cu hybrid composites with different volume fraction of β-SiC whisker were composed by Cu and β-SiC. Nanometer β-SiC and whisker were nonumiform in the matrix, had aggregation phenomenon, and they intertwined together inito a mesh. The relative density, thermal expansion coefficient and friction coefficient decreased with the increase of the volume fraction of β-SiC whisker.