Abstract:Copper, iron and cobalt based pre-alloyed powders for diamond tools were prepared by ultrahigh pressure water atomization (UPWA) process. Pre-alloyed powders prepared by different processes including UPWA, conventional water atomization (CWA) and elemental metal mechanical mixing (EMMM) were sintered to segments and then compared in mechanical properties, holding force between matrix and diamond, fracture morphology of blank and sintering diamond section containing matrix. The results showed that the pre-alloyed powder prepared by UPWA exhibits the best mechanical properties including the relative density, the hardness and the bending strength of matrix sintered segment. Sintered segments fractography of UPWA pre-alloyed powder indicates mechanical mosaic strength and chemical bonding force between the pre-alloyed powder and the diamond, leading to the great increase in the holding force between matrix and diamond. The mechanical performance and the service life of diamond tools were greatly improved by UPWA pre-alloyed powders.

Key words: ultrahigh pressure water atomization; pre-alloyed powders; diamond tools; sintered segments