Nanoengineered Polycrystalline Diamond Composites with Advanced Wear Resistance and Thermal Stability
Valéry N. Khabashesku, В. П. Филоненко, R. Kh. Bagramov, И. П. Зибров, A. S. Anokhin
Abstract
Fluorinated grains of micrometer size diamonds overcoated with nanodiamond particles were used as a feedstock for high-pressure, high-temperature synthesis of new polycrystalline diamond composites (PDCs). Such a nanoengineering approach for exploring the interfacial chemistry of diamonds has been implemented in two methods: (i) infiltration of Co from the WC-Co layer into a fluorinated diamond layer with added Al and (ii) sintering of fluorinated micro- and nanosize diamond homogeneous mixtures with added Al and Co. We found that unlike commercial PDCs made with a metallic Co binder for drilling tools, the binding phase in new composites comprises only intermetallic compound AlCo or ternary carbide AlCo3C. As a result, composites made from homogeneous mixtures showed greater promise for improving the thermal stability, while the two-layer experimental composites during granite turning tests have demonstrated >2 times higher wear resistance than leached commercial PDCs.