| 摘要 |
PURPOSE: To develop a WC-base sintered hard alloy excellent in toughness, wear resistance and impact resistance by subjecting a mixture of hard substance essentially consisting of WC and composed of the hard compounds of specified metals, a binder essentially consisting of Fe and graphite powder and executing sintering. CONSTITUTION: The raw material for forming a WC-base hard phase such as W powder, Fe powder, the powder of W-Fe alloys or the like is, if required, added with the hard powder of the carbides or nitrides of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo or the like as group 4a, 5a and 6a elements in the periodic table or their mutual solid solution, and graphite powder having 2 to 20μm average grain size for forming carbides such as WC and metal powder essentially consisting of Fe as a binder at the time of sintering are mixed so as to regulate the content thereof to 3 to 50%, which is pulverized, pressurized, compacted and is thereafter sintered at 1200 to 1600 deg.C in a nonoxidizing atmosphere. The superhard sintered body contg. planar WC crystals having 3 to 20% aspect ratio by >=20% in the whole WC and the cubic crystals of the hard compounds of Ti or the like by <=40% and using Fe as a binder can be obtd.
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