Patent Number: 6,168,066

Title: Friction stir conduction controller

Abstract: A seam (16) between juxtaposed workpieces (14) is welded or heat-treated by friction-stir using a pin tool (12) driven by an apparatus (18) which controllably positions the pin tool (12) in the vertical direction (8). The workpiece (14) is supported by an anvil (22). The joint is heated by rotation of the pin tool (12) inserted into the joint from the obverse side. In order to provide a good weld through the thickness of the workpiece, a sensor (34, 310) senses electrical characteristics near the heated or welded region, and generates a control signal which tends to control the position of the pin tool near the reverse side of the weld. The sensor is located adjacent the weld (16s) on the obverse side, and is preferably protected by mounting in a depression (22c) in the anvil (22). In one embodiment, the sensor (34) senses magnetic characteristics near the weld. In another embodiment, the sensor (310) senses conduction, conductivity, or eddy currents in the vicinity of the weld.

Inventors: Arbegast; William John (Carriere, MS)

Assignee: Lockheed Martin Corp.

International Classification: B23K 20/12 (20060101); B23K 020/12 ()

Expiration Date: 01/02/2018