Method of increasing useful life of tool steel cutting tools

Abstract From the Canadian patent

12, Abstract of the Disclosure, The wear life of a high-speed tool steel cutting bit is increased by (a) cleansing the bit by subjection to an ion beam; (b) while preventing the temperature of the cleansed bit from rising above 350°C, coating the cleansed bit by condensing sputtered atoms of titanium and boron thereonto, the condensation being carried out to provide a coating thickness of 2-6 microns. An argon or krypton beam of ions is accelerated to 1300-1800 volts as a broad-beam ion source to sputter a titanium diboride target arranged as a cathode. The sputtering is carried out for 5-10 minutes while the bit is heated to about 200°C and a soft vacuum of about 4-6 milli-torr is used …