Abstract
B4G(W, Mo)B2 hard materials were sintered by hot pressing, to develop a new hard material that is superior in heat resistance and wear resistance to other hard material. In this study, the effect of Mo content on mechanical properties and phase formation of the hard material was investigated. The results were summarized as follows:
(1) The B4C/(W, Mo)B2 hard material was densified at 2173K for 3.6ks by hot pressing.
(2) It was found that bending strength and fracture toughness were improved by adding Mo(5-20vol%) to B4C/(W, Mo)B2 hard materials. The 20vol%Mo added B4C/(W, Mo)B2 hard material had the highest values for the 4-points bending strength (850MPa) and the fracture toughness(6.1MPa. m1/2).
(3) In the case of 5-30vol% Mo added B4C/(W, Mo)B2 hard materials, the needle shaped crystals was observed in SEM micrographs. As the results of TEM, AES, XRD analysis, the needle shaped crystal phase was (W, Mo)B2 and its crystal system was hexagonal.
