# US 8,771,439 B2 · Titanium aluminide intermetallic alloys with improved wear resistance > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,439 B2 - Document ID: US8771439B2 - Status: Granted - Kind: B2 - Application number: 12/416,323 - Filed: 2009-04-01 - Published: 2010-10-07 - Granted: 2014-07-08 - Earliest claimed: 2009-04-01 - Assignees: UT-Battelle, LLC - Applicants: Jun Qu; Hua-Tay Lin; Peter J. Blau; Vinod K. Sikka - Inventors: Jun Qu; Hua-Tay Lin; Peter J. Blau; Vinod K. Sikka - Web page: https://patentgrep.com/patent/US8771439B2 ## CPC - C23C 8/10: Oxidising - C22C 14/00: Alloys based on titanium - C22C 30/00: Alloys containing less than 50% by weight of each constituent - C23C 8/80: After-treatment - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - C22C: ALLOYS (treatment of alloys C21D, C22F) ## Abstract The invention is directed to a method for producing a titanium aluminide intermetallic alloy composition having an improved wear resistance, the method comprising heating a titanium aluminide intermetallic alloy material in an oxygen-containing environment at a temperature and for a time sufficient to produce a top oxide layer and underlying oxygen-diffused layer, followed by removal of the top oxide layer such that the oxygen-diffused layer is exposed. The invention is also directed to the resulting oxygen-diffused titanium aluminide intermetallic alloy, as well as mechanical components or devices containing the improved alloy composition. ## Claims ### Claim 1 A method for producing a wear-resistant titanium aluminide intermetallic alloy, the method comprising heating a titanium aluminide intermetallic alloy in an oxygen-containing environment at a temperature of at least 950° C. for a processing time of at least about 1 hour to produce a top oxide layer and underlying oxygen -diffused layer, followed by removal of the entire top oxide layer such that the oxygen-diffused layer is exposed. ### Claim 2 (depends on 1) The method of claim 1, wherein said titanium aluminide intermetallic alloy is selected from the group consisting of Ti3Al, TiAl, and TiAl3. ### Claim 3 (depends on 1) The method of claim 1, wherein said temperature is at least 1000° C. ### Claim 4 (depends on 1) The method of claim 1, wherein said oxygen-diffused layer has a thickness of 1-300 microns. ### Claim 5 (depends on 1) The method of claim 1, wherein said oxygen-diffused layer has a thickness of 1-100 microns. ### Claim 6 (depends on 1) The method of claim 1, wherein said oxygen-diffused layer has a thickness of 1-50 microns. ### Claim 7 (depends on 1) The method of claim 1, wherein said top oxide layer is removed by abrasion. ### Claim 8 (depends on 1) The method of claim 1, further comprising shaping said wear-resistant titanium aluminide intermetallic alloy into a mechanical component. ### Claim 9 (depends on 1) The method of claim 1, wherein said titanium aluminide intermetallic alloy is in the shape of a mechanical component. ### Claim 10 (depends on 8, 9) The method of claim 8 or 9, wherein said mechanical component is a bearing. ### Claim 11 (depends on 10) The method of claim 10, wherein said bearing is a slide bearing. ### Claim 12 (depends on 8, 9) The method of claim 8 or 9, wherein said mechanical component is a component normally subjected to elevated temperatures and required to be heat resistant. ### Claim 13 (depends on 12) The method of claim 12, wherein said mechanical component is selected from the group consisting of a turbine fan, compressor blade, a part of a thermal protection system, an exhaust engine valve, piston, and a turbocharger. ### Claim 14 (depends on 1) The method of claim 1, wherein said wear-resistant titanium aluminide intermetallic alloy has a microindentation Knoop's hardness of at least 6.0 GPa. ### Claim 15 (depends on 1) The method of claim 1, wherein said wear-resistant titanium aluminide intermetallic alloy has a microindentation Knoop's hardness of at least 7.0 GPa. ### Claim 16 (depends on 1) The method of claim 1, wherein said wear-resistant titanium aluminide intermetallic alloy possesses a wear rate that is at least 10 times less, under substantially identical testing conditions, compared to the wear rate of a titanium aluminide intermetallic alloy of same composition but not possessing said exposed oxygen-diffused layer. ### Claim 17 (depends on 1) The method of claim 1, wherein said wear-resistant titanium aluminide intermetallic alloy possesses a steady-state friction coefficient that is at least 10% reduced, under substantially identical testing conditions, compared to the steady-state friction coefficient of a titanium aluminide intermetallic alloy of same composition but not possessing said exposed oxygen -diffused layer. ### Claim 18 (depends on 1) The method of claim 1, wherein said temperature is at least 1050° C. ### Claim 19 (depends on 1) The method of claim 1, wherein said temperature is about 1100° C. ### Claim 20 (depends on 1) The method of claim 1, wherein said temperature is up to about 1100° C.