Characterization and heat transfer model analysis of diamond/copper composite materials prepared by high-temperature lamination

Diamond/copper(D/Cu) composites exhibit excellent properties of high thermal conductivity(TC) and low coefficient of thermal expansion(CTE), and thus hold broad application prospects in fields such as aerospace and electronic packaging. In this study, a novel fabrication process for D/Cu composite plate is presented, utilizing tungsten-coated diamond and copper sheets as raw materials. The results show that the TC of the D/Cu composite prepared by the high-temperature laminate process can reach 630.3 W/m·K. In comparison with the D/Cu composite prepared by the traditional hot pressing process, the composite prepared by the high-temperature laminate process exhibits higher smoothness and accuracy. Additionally, the flexural strength of the composite plate is as high as 283.7 MPa. Notably, the TC of the composite plate decreases by only 1 % after 100 thermal shock cycles. The diamond and tungsten carbide within the coating form a highly stable semi-coherent phase boundary. A simplified series-parallel model was employed to calculate the in-plane(xy) and out-of-plane(z) TC of the D/Cu plate. The modified model accurately describes the TC of D/Cu composites with high volume fractions, and the results were validated using finite element analysis. This study is of significant importance for addressing the processing challenges associated with D/Cu composites.