SINTERED DIAMOND HAVING HIGH HARDNESS AND ITS PRODUCTION

摘要

PURPOSE:To prevent the cracking of diamond and falling off of diamond particles and obtain a sintered material for a die suitable for the production of a large-diameter high-strength wire by controlling the difference of the bonding phase composition and the ratio of iron-group metal in a sintered material composed of a bonding phase of diamond and iron-group metal, etc. CONSTITUTION:A bonding phase component consisting of an iron-group metal and/or a eutectic composition consisting of an iron-group metal and a carbide of group 4A, 5A or 6A element of the periodic table is prepared beforehand. The bonding phase component is uniformly mixed with diamond constituting the main component and the mixture is sintered at a high temperature under a high pressure to convert the diamond to a thermodynamically stable state. The bonding phase composition difference in the sintered material is suppressed to <=5% and the composition of the sintered material is uniformized from the circumferential part to the core part. The ratio of the iron-group metal in the sintered material is adjusted to 1-30vol.% (based on diamond).