| 摘要 |
PROBLEM TO BE SOLVED: To produce the diamond sintered compact which is used for a drilling bit and has high strength and also is excellent in fracture resistance, heat, acid and wear resistances, by using a mixture of yttrium oxide and an iron group metal oxide, or a double oxide of yttrium and an iron group metal, as a sintering aid for the sintered compact. SOLUTION: This sintered compact comprises 1 to 20 vol.% of a material consisting of a compound or mixture, that contains yttrium, an iron group metal and oxygen, and the remainder of a diamond powder having a 20 to 200 μm average particle size. As the compound or mixture, that contains yttrium, an iron group metal and oxygen, a double oxide of yttrium and an iron group metal, such as Fe2 Y2 O6 , or a mixture of yttrium oxide and an iron group metal oxide, is used. This production of the diamond sintered compact for a drilling bit comprises: mixing a powdery oxide mixture or double oxide of yttrium and an iron group metal with a diamond powder having the above average particle size or a powdery mixture of this diamond powder and non- diamond carbon to obtain a mixed powder; and sintering the resulting mixed powder under pressure and temp. conditions within the thermodynamically stable region of diamond. |
