Apparatus and method for forming weld joints having compressive residual stress patterns
AssigneesThe Boeing Company, Lambda Research, Inc.
InventorsMichael Royston James, Murray W. Mahoney, Douglas J. Waldron, Paul S. Prevey, III
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Abstract
The welding apparatus and associated method are provided. The welding apparatus includes a welding tool for forming a weld joint along the surface of at least one workpiece. The welding apparatus also includes a compression tool for selectively inducing a layer of residual compressive stress in at least a portion of the surface of the weld joint and the surface of the at least one workpiece to thereby improve the material properties of the workpiece, including corrosion resistance and fatigue strength.
Claims29
A structural assembly, comprising:
- at least one workpiece;
- a weld joint disposed along at least a portion of the surface of said at least one workpiece;
- and
- wherein, at least a portion of the surface of said weld joint and the surface of said at least one workpiece adjacent the weld joint comprise a selectively formed layer of residual compressive stress having a depth of approximately 0.5 mm to approximately 1.5 mm and having an associated cold working of less than about 12 percent to thereby improve the corrosion resistance and fatigue strength of said portion of the surface of said weld joint and the surface of said at least one workpiece.
A structural assembly being formed by a process comprising the steps of:
- welding at least one workpiece along a predetermined path to form a weld joint;
- and
- inducing a layer of residual compressive stress in at least a portion of the surface of the weld joint and the surface of the at least one workpiece adjacent the weld joint having a depth of approximately 0.5 mm to approximately 1.5 mm and having an associated cold working of less than about 12 percent.
A structural assembly being formed by a process comprising the steps of:
- forming a friction stir weld joint along a surface of at least one workpiece;
- and
- concurrently with said forming step, burnishing at least a portion of the surface of the weld joint and the surface of the at least one workpiece adjacent the weld joint to thereby selectively induce a layer of residual compressive stress therein having an associated cold working of less than about 12 percent.
Dependencies are inferred from the claim text.