Diamond-containing cemented metal carbide.

摘要

Cemented tungsten carbide rock bit inserts (18) have diamond particle dispersed therein for enhanced hardness and war resistance. The cobalt matrix is primarily the face centered cubic crystal structure for enhanced ductility and toughness. Such inserts (18) are formed by introducing excess non-diamond carbon beyond the stoichiometric proportion in the tungsten carbide. The inserts (18) are pressed at a temperature and pressure where diamond is thermodynamically stable and cooled while maintaining the pressure sufficiently high to prevent decomposition of diamond crystals formed at the elevated temperature. Diamond crystals may be dispersed throughout the cemented tungsten carbon or may be more concentrated near the surface than in the interior.