EFFECT OF THERMAL TREATMENT ON THE CONTENT AND PROPERTIES OF THE DIAMOND-CaMg(CO3)2 COMPOSITE OBTAINED BY THERMOBARIC SINTERING
Abstract
Diamond-CaMg(CO3)2 composite was sintered at the high pressure of 8.0 GPa and high temperature of 2100°C. Samples of the composite were annealed under ambient air in temperature range of 700-1200°C. It has been established that at annealing temperatures of more than 900°C, the CaMg(CO3)2 component of composite completely decomposes and the CaO and MgO phases are observed in the structure of the sintered material. The graphitization of the diamond phase in the structure of the diamond-CaMg(CO3)2 composite after annealing under ambient air ap to temperature of 1200°C was not detected. The process of decomposition of complex carbonate of CaMg(CO3)2 in the composite structure at annealing under ambient air leads to a decrease in the Young's modulus from 940 GPa at 700°C to 740 GPa at 1200°C. Testing of composite plates while turning granite shows that their wear resistance index remains unchanged within the entire temperature range of the annealing for this investigation.
