Abstract: 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.

Abstract: A duplex strengthened structural steel that is particularly suitable for demanding applications which require both high yield strength and fatigue properties is provided. The preferred steel alloys of this invention are characterized by both the presence of intermetallic strengthening precipitates like maraging steels, as well as alloy carbide strengtheners as is common with secondary hardening steels. Titanium is substantially absent from the preferred steel alloys of this invention. Thus the formation of nonmetallic inclusions, such as titanium carbonitrides, are alleviated which correspondingly enhances the fatigue properties of the preferred alloys. To compensate for the lack of titanium strengthening precipitates within the alloy, additions of aluminum are provided such that the aluminum forms intermetallic strengthening precipitates with nickel.

Abstract: A method of case hardening ferrometallic parts that avoids the use of protective coatings or shields is provided. The process comprises the steps of a) carburizing the entire part, b) machining the carburized part to form first and second surface regions wherein the second surface region has a carbon content at least 100% greater than the carbon content of the first surface region, c) heating the machined part at a hardening temperature with the entire part in contact with a gaseous atmosphere containing a source of carbon and a carbon content of from 85% to 115% of the carbon content of said first surface region, and d) quenching the part.