Research Of SiC_p/Cu Composite Prepared By Powder Metallurgy And Its Properties

SiC_p/Cu composite is a new structural-functional integration material, which has a promising potential in future capplication due to their good combination of electric conduetivity(EC), mechanical property and tailorable CTE.The 50μmβ-SiC powder was used in present work,and coated with Cu by electroless copper plating process,then the composition and morphology of SiC_p/Cu composite powders were also analyzed by SEM and EDS methods. SiC_p/Cu composites were fabricated by vacuum at 900℃for the coated powder,the volume of SiC in the composites was of 30vol%,40vol% and 50vol% respectively. The microstructure and interface structure of the SiC_p/Cu composites were observed by metallographic microscope and SEM methods, and the phase structure of the SiC_p/Cu composites were observed by XRD method. The Rockwell hardness, frictional wear property, electric conductivity(EC) and coefficient of thermal expansion(CTE) of the composites were measured, and the effect of the volume of SiC on the Rockwell hardness, frictional wear property, EC and CTE of SiC_p/Cu composites were also discussed. The main results are:Electroless copper planting under 50℃, pH=12.5, CuSO₄·5H₂O 30g/L,EDTA·2Na 1g/L,K₄[Fe(CN)₃]·3H₂O 2g/L,NaOH 34 g/L,HCHO 24 ml/L and C₄H₄O₆KNa·4H₂O 105 g/L, the Cu coating on the surface of SiC particles is uniformity and densification, the interface between SiC particles and Cu matrix is bonded well. The coating quality of C₄H₄O₆KNa·4H₂O and EDTA·2Na is better than C₄H₄O₆KNa·4H₂O.The melting point of Cu crystallite on the surface of SiC is lower than pure Cu, so the sintering character between SiC particles and Cu improved, and Cu coating and Cu powders speedy opacification, the densifieation of SiC_p/Cu composite is 96%. The composites were free of porosity and the SiC particles distribute uniformly in the composites; and the phase composition of SiC_p/Cu are Cu and SiC, no other reaction product.The Rockwell hardness and wear-resisting property of the composites mainly controlled by the volume of SiC when the volume of SiC is less than 40%; the Rockwell hardness and wear-resisting property of the composites mainly controlled by porosity when the volume of SiC is more than 40%. The Rockwell hardness is 25.2HRC when the volume of SiC is 40%.The wear-resisting property of SiC_p/Cu composite increased with the increasing of SiC content. The abrasion mechanism of SiC_p/Cu composites is coactions of grain-abrasion and adhesion-abrasion, the abrasion mechanism of SiC_p/Cu composites is adhesion-abrasion of Cu when the volume of SiC is 30%, with the increasing of SiC content, the grain-abrasion is more patency.With the increasing of SiC content, the CTE of SiC_p/Cu composites decreased, but the ambient temperature resistivity increased.