| 摘要 |
PROBLEM TO BE SOLVED: To obtain a sintered article which has high hardness, high toughness, high thermal shock resistance and high oxidation resistance, by dispersing titanium boride-zirconium boride solid solution particles having a specific average diameter in a silicon carbide sintered product in a specific rate and specifying the relative density. SOLUTION: This sintered article is obtained by adding prescribed amounts of TiB2 and ZrB2 or ZrC to raw materials for the silicon carbide sintered product, kneading the mixture, molding the kneaded product, sintering the molded product under vacuum or in the flow of an inert gas without adding a pressure, and then subjecting the sintered product to a hot hydrostatic pressure press sintering treatment in an Ar gas atmosphere. The sintering treatment is preferably carried out at a highest temperature of 1,950 to 2,200 deg.C for 4 hr or longer, The titanium boride-zirconium boride solid solution particles expressed by the formula: Ti1-xZrxB2 [0.02<=(x)<=0.25] having an average particle diameter of 1 to 10 μm are dispersed in the silicon carbide(SiC) sintered product in a volume fraction of 20 to 70%, and the particle-dispersed silicon carbide-based sintered product has a relative density of >=99%. The sintered product is cut to obtain a guide roller which has excellent abrasion resistance and excellent lacking resistance and is used for rolling metal wire rods. |
