# US 8,540,134 B2 · Reinforcement of friction plug welds > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,540,134 B2 - Document ID: US8540134B2 - Status: Granted - Kind: B2 - Application number: 12/557,715 - Filed: 2009-09-11 - Published: 2011-03-17 - Granted: 2013-09-24 - Earliest claimed: 2009-09-11 - Assignees: The Boeing Company - Applicants: David M. Bezaire; John M. Comfort; John G. Vollmer; Mark A. Fischer - Inventors: David M. Bezaire; John M. Comfort; John G. Vollmer; Mark A. Fischer - Web page: https://patentgrep.com/patent/US8540134B2 ## CPC - B23K 20/12: the heat being generated by friction; Friction welding - B23K 20/1205: {using translation movement} - B23K 20/1215: {for other purposes than joining, e.g. built-up welding} - B23K 20/122: {using a non-consumable tool, e.g. friction stir welding} - B23K 20/127: {Friction stir welding involving a mechanical connection} - B23K 20/1275: {involving metallurgical change} - B23K 20/128: {making use of additional material} - B23K 20/1285: {Portable friction welding machines} - B23K 20/129: {specially adapted for particular articles or work} - B23K 20/1295: {Welding studs} - 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 ## Abstract A hole in a metal workpiece is filled by friction plug welding. The weld between the workpiece and the plug is reinforced by a weld land in the workpiece that surrounds one end of the plug. The weld land is formed by extruding a portion of the plug into a cavity in an anvil used in the welding process. ## Claims ### Claim 1 A method of filling a hole in a metal workpiece, comprising: friction welding a plug in the hole to form a friction weld, wherein the friction weld consists of only the plug and the workpiece metal; and forming a weld land on a root side of the workpiece during the friction weld, said weld land comprising plug material and workpiece material, wherein the weld land extends a predetermined height above a surface of the root side of said workpiece, wherein the weld land has a predetermined width, and wherein forming the weld land is performed by: placing an anvil against the workpiece and around the hole, the anvil comprising a first cavity having a bottom surface facing the workpiece, the first cavity configured to receive the plug, the anvil further comprising a second cavity substantially surrounding the first cavity, wherein the second cavity is larger in diameter and smaller in depth relative to the first cavity, wherein the second cavity comprises a tapered recess surrounding the first cavity, wherein the tapered recess is angled downwardly toward the first cavity relative to a depth of the first cavity; and urging a portion of the workpiece into the first cavity, and thereafter into the second cavity. ### Claim 2 (depends on 1) The method of claim 1, wherein the friction welding is performed by: rotating the plug, and forcing the rotating plug into the hole, the first cavity, and the second cavity. ### Claim 3 (depends on 1) The method of claim 1, further comprising: removing portions of the plug that extend beyond the workpiece after the plug has been friction welded in the hole. ### Claim 4 (depends on 1) The method of claim 1, wherein the first cavity is defined by sidewalls inclined at a first angle relative to a second angle defined by a slope of the tapered recess, and wherein the first angle is greater than the second angle. ### Claim 5 (depends on 1) The method of claim 1, wherein the weld land is left as welded. ### Claim 6 (depends on 1) The method of claim 1, wherein the weld land is machined down by an amount. ### Claim 7 (depends on 6) The method of claim 6, wherein the amount is sufficient to leave the weld land extending past the surface. ### Claim 8 (depends on 6) The method of claim 6, wherein the amount is sufficient to remove the weld land. ### Claim 9 A method of friction plug welding a workpiece, comprising: rotating a plug; plasticizing a portion of the plug and filling a hole in the workpiece by forcing the rotating plug through the hole and against an anvil to friction weld said plug in said hole, wherein the anvil comprises a first cavity having a bottom surface facing the workpiece, the first cavity configured to receive the plug, the anvil further comprising a second cavity substantially surrounding the first cavity, wherein the second cavity is larger in diameter and smaller in depth relative to the first cavity, wherein the second cavity comprises a tapered recess surrounding the first cavity, wherein the tapered recess is angled downwardly toward the first cavity relative to a depth of the first cavity; during plasticizing, also substancially filling the first cavity and the second cavity with the plug; and, forming a weld land on the workpiece, wherein the weld land consists of only workpiece material and plug material, wherein the weld land extends a predetermined height above a surface of a root side of said workpiece, and wherein the weld land has a predetermined width. ### Claim 10 (depends on 9) The method of claim 9, wherein the first cavity is defined by sidewalls inclined at a first angle relative to a second angle defined by a slope of the tapered recess, and wherein the first angle is greater than the second angle. ### Claim 11 A method of friction plug welding a metal workpiece, comprising: rotating a plug; forcing the rotating plug into one end of a hole passing through the workpiece; plasticizing a first portion of the plug and a second portion of the workpiece using heat generated by frictional engagement between the rotating plug and the workpiece; placing an anvil against the workpiece; forge welding the plug to the workpiece, including forcing the plug against the anvil; reinforcing the weld by urging the first portion into a first cavity in the anvil, the first Cavity having a botton surface and reinforcing the weld also including urging the second portion into a second cavity in the anvil, wherein the second cavity substantially surrounds the first cavity, wherein the second cavity has a larger diameter and a smaller depth relative to the first cavity, wherein the second cavity comprises a tapered recess surrounding the first cavity, wherein the tapered recess is angled downwardly toward the first cavity relative to a depth of the first cavity, and wherein urging the first portion and the second portion forms a weld land on the workpiece, wherein the weld land extends a predetermined height above a surface of a root side of said workpiece and wherein the weld land has a predetermined width. ### Claim 12 (depends on 11) The method of claim 11, wherein the first cavity is defined by sidewalls inclined at a first angle relative to a second angle defined by a slope of the tapered recess, and wherein the first angle is greater than the second angle.