Effect of SiC content on properties of copper matrix composites

SiC/Cu composites were prepared by hot-pressing powder metallurgy with Al and Mg elements, and the effect of SiC volume percentage on the properties of SiC/Cu composites was studied. X-ray diffraction, Archimedes drainage method, three-point bending method and scanning electron microscope were used to analyze the phase composition, relative density, mechanical properties and micro-morphology of the composite samples, and the thermal conductivity and thermal expansion coefficient were measured. The thermal expansion coefficient of the composite was predicted by ROM mixing law and Turner model. Experimental results show that AlCuMg phase is formed in the matrix of the sample, and the strength is greatly increased, and the mixed fracture is the main type of the sample. The SiC particles are uniformly dispersed in the matrix when the SiC content is low. The density, bending strength, thermal conductivity and thermal expansion coefficient of SiC/Cu composites are 98.81%, 478 MPa, 254.76 W/(m·K) and 11.84 × 10⁻⁶/K respectively when the SiC content is 35%. When the content of SiC increases, the agglomeration of SiC particles is serious, and the density, bending strength, thermal conductivity and thermal expansion coefficient of the composites decrease. Its hardness increases at first and then decreases, and reaches the maximum value of 110 HRB when the SiC content is 45%. The Turner model is the closest to the measured values of composites.