Enhanced thermal conductivity in Cu/diamond composites by tailoring the thickness of interfacial TiC layer

Abstract

Diamond particles reinforced Cu matrix (Cu/diamond) composites were fabricated by gas pressure infiltration using Ti-coated diamond particles with Ti coating from 65 nm to 850 nm. The scanning transmission electron microscopy (STEM) characterizes that the Ti coating transforms from elemental Ti to TiC after infiltration, and the crystallographic orientation relationship between diamond and TiC is [1 1 0]diamond//[1 1 0]TiC and (1 1 1)diamond//(1 1 1)TiC. The thermal conductivity of the Cu/Ti-diamond composites firstly increases and then decreases with increasing Ti coating thickness, giving a maximal value of 811 W m−1 K−1 at 220 nm Ti-coating layer. The results clearly manifest the effect of interfacial layer thickness on the thermal conductivity of Cu/diamond composites.