Beta titanium alloy surface hardening method

The invention discloses a method for hardening the surface of a beta titanium alloy. The method comprises the following steps: 1, carrying out cleaning pretreatment on the beta titanium alloy; 2, placing the cleaned and pretreated beta titanium alloy in titanium and titanium alloy surface oxygen-carbon co-permeation equipment, vacuumizing, heating to the solid solution temperature of the beta titanium alloy, introducing CO2 for primary heat preservation, introducing CO2 for cooling to the aging temperature of the beta titanium alloy, introducing CO2 for secondary heat preservation, and introducing CO2 for cooling or furnace cooling to the room temperature, so as to obtain the titanium and titanium alloy surface oxygen-carbon co-permeation titanium alloy surface oxygen-carbon co-permeation titanium and titanium alloy surface oxygen-carbon co-permeation titanium and titanium alloy surface oxygen-carbon co-permeation titanium and titanium alloy surface oxygen-carbon co-permeation titanium and titanium alloy. And