US Patent 7771649 Method of producing ultrafine crystalline TiN/TIB

Disclosed herein is a method of producing an ultrafine crystalline TiN/TiB2 composite cermet. In the method, titanium nitride (TiN)/titanium boride (TiB2)/stainless steel composite nanopowder is produced through a reaction milling process using titanium (Ti), boron nitride (BN), and stainless steel powders as raw material powders, and the resulting composite nanopowder is liquid-phase sintered. The method comprises a first step of mixing titanium powder and boron nitride powder at a molar ratio of 3:2, a second step of mixing 5-60 wt % stainless steel powder and the powder mixture, a third step of feeding the powder mixture along with a ball having a predetermined diameter into a jar and conducting a high energy ball milling process to produce titanium nitride/titanium boride/stainless steel composite nanopowder, and a fourth step of shaping and sintering the resulting composite nanopowder.