Effect of the contact conductivity of the diamond–metal binder interface on the thermal conductivity of diamond-containing composites

The effect has been studied of the contact conductivity of the diamond–metal binder interface on the thermal conductivity of diamond-containing composites having two- and three-component nickel-based metal binders. A device and procedure have been developed for measuring the thermal conductivity coefficients of binders and based on them diamond-containing composites. The dependence of the thermal conductivity coefficients on the compositions (particularly, the presence of the carbide-forming additives) and structures has been analyzed. A theoretical model of the composite has been proposed, which allows for the real shape of a diamond crystal and contact conductivity of its faces. The estimation of the thermal contact conductivity of the interface has been derived by solving the inverse problem. It agrees satisfactory with the literature data on direct physical studies and similar estimates for composites with aluminum and copper binders. The influence of the contact resistance on the temperature mode of the diamond tool operation has been indicated by the results of modeling.