A bearing includes a bearing component, such as a bearing race, having a bearing contact surface. A region at the bearing contact surface is made of titanium aluminide, preferably an alpha-2 or gamma titanium aluminide. A case-hardened layer present at the surface of the titanium aluminide region increases the hardness and wear resistance of the titanium aluminide at elevated temperature. The case-hardened layer is preferably formed by diffusing carbon into the surface of the titanium aluminide from a gaseous medium, at elevated temperature land at ambient or reduced pressure.