# US 11,440,134 B2 · Method of joining dissimilar metals through friction stir welding and multi-metal component > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,440,134 B2 - Document ID: US11440134B2 - Status: Granted - Kind: B2 - Application number: 16/448,482 - Filed: 2019-06-21 - Published: 2020-12-24 - Granted: 2022-09-13 - Earliest claimed: 2019-06-21 - Assignees: GM Global Technology Operations LLC - Applicants: GM Global Technology Operations LLC - Inventors: Huaxin Li; Dale A. Gerard; Adam G. Kotlarek - Web page: https://patentgrep.com/patent/US11440134B2 ## CPC - B23K 20/128: {making use of additional material} - B23K 20/122: {using a non-consumable tool, e.g. friction stir welding} - B23K 20/129: {specially adapted for particular articles or work} - B62D 21/11: with resilient means for suspension {, e.g. of wheels or engine; sub-frames for mounting engine or suspensions} - B62D 29/00: Superstructures, {understructures, or sub-units thereof,} characterised by the material thereof {(B62D33/044, B62D33/048 take precedence)} - B62D 29/008: {predominantly of light alloys, e.g. extruded} - C22C 9/01: with aluminium as the next major constituent - C22C 38/04: containing manganese - C22C 38/42: with copper - B23K 2101/006: {Vehicles} - B23K 2103/20: Ferrous alloys and aluminium or alloys thereof - B62D 27/023: {Assembly of structural joints} - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) - C22C: ALLOYS (treatment of alloys C21D, C22F) ## Abstract A component, which may be an automotive chassis structure, includes first and second sub-part main bodies. The first sub-part main body is formed of a first material, and the second sub-part main body is formed of a second material. The first material is a steel alloy, and the second material is aluminum or an aluminum alloy. A transition layer is attached to and contacts the first sub-part main body. The transition layer is formed of a third material, where the third material contains at least a majority of copper. A mixed layer is disposed between the transition layer and the second sub-part main body, and the mixed layer is formed of a mixture of the second material and the third material. A disclosed method includes forming the component by friction stir welding the transition layer to the second sub-part main body. ## Claims ### Claim 1 A method of joining dissimilar metals, the method comprising: providing a first component formed of a steel alloy; disposing a transition layer onto the first component, the transition layer having a base layer disposed on the first component and an outer layer disposed on the base layer, the base layer being substantially formed of copper, and the outer layer being substantially formed of an alloy containing copper, aluminum, and tin; providing a second component formed of aluminum or an aluminum alloy and disposing the second component adjacent to the transition layer so that the transition layer is disposed between the first component and the second component; and friction stir welding the transition layer to the second component. ### Claim 2 (depends on 1) The method of claim 1, further comprising attaching the transition layer onto the first component via laser cladding. ### Claim 3 (depends on 2) The method of claim 2, further comprising providing the transition layer having a thickness in the range of 5 to 20 millimeters. ### Claim 4 (depends on 1) The method of claim 1, further comprising providing the steel alloy as a steel alloy selected from the group consisting of: HSLA 340, HSLA 420, and HSLA 550. ### Claim 5 (depends on 1) The method of claim 1, further comprising providing the steel alloy comprising: copper in an amount not exceeding 0.4 weight percent; manganese in an amount not exceeding 1.5 weight percent; chromium in an amount not exceeding 1.5 weight percent; nickel in an amount not exceeding 2.00 weight percent; and at least one of vanadium and niobium in amounts not exceeding 0.4 weight percent each. ### Claim 6 (depends on 1) The method of claim 1, further comprising providing the base layer comprising: aluminum in an amount not exceeding 10 weight percent; iron in an amount not exceeding 6 weight percent; and at least 75 weight percent copper. ### Claim 7 (depends on 6) The method of claim 6, further comprising providing the base layer comprising: nickel in an amount not exceeding 6 weight percent; manganese in an amount not exceeding 2 weight percent; and zinc in an amount not exceeding 0.5 weight percent. ### Claim 8 (depends on 1) The method of claim 1, further comprising providing the first component having a plurality of first component sides and a first component distal end connecting the plurality of first component sides, each first component side of the plurality of first component sides having a greater surface area than a surface area of the first component distal end, and the second component having a plurality of second component sides and a second component distal end connecting the plurality of second component sides, each second component side of the plurality of second component sides having a greater surface area than a surface area of the second component distal end, the step of disposing the transition layer onto the first component comprising disposing the transition layer onto the first component distal end, the first component distal end abutting the second component distal end with the transition layer disposed between the first component distal end and the second component distal end.