Ultrahigh pressure apparatus for diamond synthesis

摘要

An ultrahigh pressure apparatus for diamond synthesis or the like which comprises a pair of opposed frustoconical punches with a flat end surface, an annular die made of a very hard metallic material and placed between said punches, a hollow cylinder made of a sintered alumina to be free of pores having an inner diameter substantially equal to that of the flat end surface of the punches, a pair of gaskets around and adjacent to the flank of said punches which gaskets each having an outer diameter larger than that of said hollow cylinder and said die having at the middle portion thereof a substantially concentric cylindrical projection of an axial length equal to that of said hollow cylinder so that the bore is tightly fitted to the gaskets and the hollow cylinder.