GB1311690A - Boriding - Google Patents

Abstract

1311690 Boriding agent; titanium boride INSTITUT FUR HARTEREI-TECHNIK 7 Oct 1970 47741/70 Heading C1A A boriding agent for boriding a metal comprises amorphous boron, which has previously been ignited and cooled under a rare gas (preferably arcon), as boron donor. The boriding agent is produced by igniting amorphous boron at 850‹ to 1100‹ C. for 1 to 3 hours while a rare gas is simultaneously conducted through the boron, which is thereafter cooled with the further conduction therethrough of rare gas. The boriding agent may be providing with activators which increase the thickness of the hardened skin produced by the boriding agent on the treated material. Examples of activators are alkali metal, alkaline earth metal and ammonium halides. Also an inert substance which acts as a thinner, e.g. stable oxides, talc and asbestos may be included in the boriding agent. Titanium or titanium alloy workpieces when borided by this method generally have a hardened surface with a thickness of 0À04 to 0À1 mm. comprising the titanium borides TiB 2 and TiB. During the boriding operation, which occurs at 900‹ to 1400‹ C. for at least 3 hours rare gas is constantly conducted through the boriding agent in a vessel only with an inlet and outlet for the rare gas. The material is then cooled.