PURPOSE: To obtain a sintered compact excellent in strength, hardness, wear and shock resistances by directly forming the metal carbide of a diamond-metal carbide sintered compact from metal powder and diamond particles during sintering.

CONSTITUTION: When a sintered compact consisting of 10-60vol.% dispersed phase of diamond particles and the balance matrix phase of carbide of a group IVa, Va or VIa metal of the Periodic Table is produced, a mixture of powder of the group IVa, Va or VIa metal with diamond particles is press-fired. The diamond powder and the metal powder cause a solid phase reaction under heating and pressing, carbide of the metal is formed as a reactional product in the resultant sintered compact and the objective dense composite contg. diamond particles uniformly dispersed in a metal carbide is obtd. even under such a low pressure as to give an unstable region of diamond.