Enhanced thermal conductivity and stability of diamond/aluminum composite by introduction of carbide interface layer

• A coating on diamond improved thermal conductivity of the composites.
• The coating inhibited the formation of Al4C3 during the infiltration.
• The survived coating improves the moisture stability of the composites.

W-coated diamond/aluminum composites were manufactured by a pressure infiltration method. A continuous and homogeneous carbide coating was formed on the surface of diamond particles, and the selective bonding between the aluminum matrix and different diamond faces was no longer observed. The obtained composites exhibited thermal conductivity as high as 476 W⋅m− 1⋅ K− 1. It was attributed to the carbide layer which increased the amount of reactive interfacial bonding and improved the mean interfacial thermal conductance. In addition, compared with the W coated diamond/aluminum composites, the thermal conductivities of uncoated ones were seriously declined by immersing the composites in moisture circumstances. SEM and XRD results indicated that the stabilities of composites thermal behaviors were closely related to the interface of composites. The W carbide layer in the interface region played a critical role in improving the stability of the composite exposure to moist environments.