STUDY OF THE STRUCTURE AND WEAR RESISTANCE OF MATERIALS OF SIC – TIC, SIC – VC SYSTEMS OBTAINED BY ELECTOSPARK SINTERING

Abstract

The carbon content in the starting powders and inclusions of titanium and vanadium carbides in SiС–TiС, SiС–VC composites obtained by electric spark sintering at a temperature of 2000°C, a pressure of 45 MPa, and a holding time of 30 min was investigated. It was found that the carbon content in vanadium carbide inclusions in the SiC-VC composite is ~85% higher than the carbon content in the starting VC powder. The effect of the content of titanium and vanadium carbides on the porosity of the composites was investigated. It was found that the porosity of the composites decreases from 30.4% in silicon carbide to 0.1% at a titanium carbide concentration in the starting charge of 40 vol.% and to 1.3% at a vanadium carbide concentration in the starting charge of 40 vol.%. The effect of the content of titanium and vanadium carbides on the wear resistance of the composites was investigated. It was found that with a content of 40 vol.% of titanium and vanadium carbides in the initial charge in composites sintered at 2000^oC, holding time of 30 min., the wear resistance is practically the same and is 16-17. The wear resistance of SiC-TiC composites sintered at 1900, 2000^oC increases with increasing holding time to 30 min. and decreases with increasing holding time to 45 min. The wear resistance of SiC-VC composites sintered at 1900, 2000^oC increases in the interval of 15-45 min. holding time.