Thermal conductivity of Cu/diamond composites by orthogonal experiment method

Cu/diamond composites were prepared by high temperature and high pressure(HTHP) method.Factors including diamond grit size,the volume ratio of two sizes of diamond,the volume ratio of Cu and diamond,and the time of pressure maintaining and heat preservation were investigated to illustrate their influences on the thermal conductivity of composites based on orthogonal experiments.The results showed that the volume ratio of Cu and diamond was the most pivotal factor,while the volume ratio of two sizes of diamond was the least impact on the thermal conductivity.In order to improve the thermal conductivity of Cu/diamond composites,the optimized preparation process parameters were studied and obtained as follows: the volume ratio of large size(250 μm) diamond to the small size(75μm) diamond was 1∶ 4,the volume ratio of Cu and diamond was 7∶ 3,the time of pressure maintaining was 2 h.Under the optimized parameters,Cu/diamond composites with thermal conductivity of 238.18 W /(m·K) were obtained.