VC Addition Prepared Ultrafine WC-11Co Composites by Spark Plasma Sintering Original Research Article

Cemented carbide powders based on WC-1 11Co with a grain size of about 2OOnm with various extents of VC addition were consolidated to full density by spark plasma sintering (SPS). The density, microstructure, fracture surfaces, hardness and fracture toughness of the SPS consolidated samples were measured and observed. Dense samples were obtained by SPS at a temperature of 1200% (5min, 40MPa). Adding inhibitor VC decreases the WC grain growth in SPS, but the excessive additive can not inhibit the grain growth. The fracture mode can be observed as brittle fracture and intergranular fracture. With 0.5wt% VC addition, WC grain size decreased from 540 to 380 nm, the hardness increased from 1828 to 1902HV30. The adding amount of VC should be controlled the certain range and the samples of appropriately adding VC can achieve the samples possessed better hardness and toughness.