| 摘要 |
A diamond body 46 which comprises a matrix of self-bonded diamond grains formed using a catalyst. A first region 48 of the body 46 extends from a surface 49 thereof, is substantially free of the catalyst and least some of the pores between diamond grains comprise an inert metal and a metal carbide formed by reaction between the diamond and a second metal. A second region 50 of the body 46 which is adjacent the first 48 comprises a Group VIII metal in pores between diamond grains. Preferably pores in the first region 48 adjacent said surface 49 comprise a relatively greater amount of carbide and a lower amount of inert metal than the pores adjacent the second region 50. The carbide forining metal can be Ti, Zr, Nb, Mo, W, Ta, V, Cr, Hf, Si or B, the inert metal can be Cu, Ag, Au, Pt or Pd and the alloy of these metal melts at a lower temperature than the Group VIII metal, which can be the catalyst or be added after removing the catalyst. |
