Resistance of a binderless cemented carbide to abrasion and particle erosion

A binderless cemented carbide has been evaluated in abrasion and erosion tests. The binderless carbide was compared with: SiC, Al(2)O(3) and two conventional cemented carbides with 6% Co and different WC grain sizes (1 and 7 mu m). In the abrasion tests, the materials were ground with silica, silicon carbide and diamond particles in the size range of 5-15 mu m. The erosion tests were performed with 80, 200 and 600 mu m silicon carbide erodents. The angle of impingement was 45 degrees and the erodent velocity 70 m/s. In all tests, the conventional cemented carbides showed the highest, the binderless cemented carbide an intermediate and the ceramics the lowest wear resistance. Scanning electron and atomic force microscopy of the abraded surfaces revealed that the binderless cemented carbide was worn by a preferential removal of TiC grains. In erosion, the wear mechanism was largely plastic for the cemented carbides, whereas the ceramics were worn by micro-fracture. The SEM analysis also showed an impact scaling effect for the cemented carbides in erosion.