The Boeing Company

Concurrent Technologies Corporation

Kevin James Colligan

Steven J Avila

A friction stir welding tool is provided for joining together workpieces utilizing friction stir welding processes. The inventive tool includes a support body rotatable about a first axis and having a distal end defining a shoulder. A rotatable pin extends from the distal end of the support body downward and away from the shoulder. The shoulder of the support body includes at least one section that is tapered, with the taper extending downward toward the pin.

Tapered friction stir welding tool

The superplastically formed structural assembly includes first and second structural members having facing surfaces. The first and second structural members can include a first outer structural member, a second outer structural member or at least one intermediate structural member. In one embodiment, the first and second structural members include first and second outer structural members. In another embodiment, the first and second structural members include first and second intermediate structural members. The structural assembly includes at least one friction stir weld joint joining the first and second structural members. In one embodiment, the facing surface of the first structural member is at least partially covered with oxide to prevent thermo-compression welding of the first and second structural members adjacent the at least one friction stir weld joint. In another embodiment, the facing surface of the second structural member is at least partially covered with oxide.

Application of friction stir welding to superplastically formed structural assemblies

A method and apparatus for friction stir welding that produces a weld of significantly reduced surface roughness at significantly higher welding rates, in materials that are difficult to weld, such as non-extrudable aluminum alloys. The method includes cooling the stir welding tool during the welding process, thereby reducing the tendency of softened metal to adhere to the rotating pin and shoulder of the tool. The apparatus includes a tool with internal spaces or an external jacket, through which coolant can be pumped to remove heat and cool the tool during welding operations. In another embodiment, the apparatus includes a device for spraying a coolant onto exterior surfaces of the distal end of the welding tool to thereby remove heat from the tool, and the surrounding workpiece, during welding.

Friction stir welding with simultaneous cooling

An improvement to a friction stir welding tool having a rotating member, the improvement including an attachable cutting tool (30) having one or more radial cutting edges (32). A first embodiment of a cutting tool including one or more cutting inserts (42), each cutting insert having a lower end cutting edge; a like number of insert-engaging grooves (44); a collar (46) sized to closely engage around the rotating member with engaged inserts; a collar attachment arrangement for securing the collar (46) to the rotating member (38); and a number of set screws (48) for anchoring the cutting inserts (42) to the member (38). A second embodiment of a cutting tool including a cutting insert holder (60) having a lower end cutting edge; an insert holder hole (62) extending through the rotating member, the insert holder hole oriented angularly away from the rotating member axis of rotation (64); a threaded radial hole (66) formed in the rotating member (38); and a single screw fastener (68) for turning into the radial hole to press against the cutting insert holder. A third embodiment of a cutting tool including one or more tabs (80) extending radially from the rotating member (38). A cornered cutting insert (70) is removably attached to the lower end of each tab. The cornered cutting insert (70) includes one or more corners (72) to act as cutting edges. Additionally provided is an improved method of friction stir welding including attaching a cutting tool having a cutting edge to a conventional friction stir welding tool and providing liquid to the cutting edge as the weld is being formed in order to quickly cool the cutting edge surfaces so that the material will not adhere to the cutting edges, allowing the cutting tool to machine excess weld material away.

Friction stir welding

A method of root closure of friction stir welds in all types of stir weldable materials, especially difficult to weld materials, such as non-extrudable aluminum alloy 2024, 2014, 2090 and 7075. The method includes providing a backing device that has a recess, such as a groove or channel, sized to receive the tip of the pin of the welding tool and to contain the bead of the weld being formed. The workpiece rests on the backing device, with the proposed weld line aligned with the recess. Thus, as the weld is formed, material is extruded into the recess, completing closure of the weld root, and forming a small bead on the rear side of the workpiece. Optionally, this bead may be removed by a machining process. In one embodiment, the backing device is a plate with a channel machined in its surface so that the workpiece may be temporarily affixed to the plate, with weld line aligned with the channel, for welding. In an alternative embodiment, the backing device is a roller, mounted beneath the rotating pin of the friction stir welding tool, with a circumferential groove on its exterior surface, sized to receive the pin tip and contain the weld bead as the weld is being formed.

Weld root closure method for friction stir welds

A friction stir welding tool for welding workpieces of variable thickness. The tool is characterized in that the displacement between a shoulder that presses down on an upper surface of the weld, and a tip of a rotating pin that penetrates and softens the workpiece to form the weld, is variable. In one embodiment, when the tool is used in conjunction with an apparatus that allows the shoulder of the tool to ride on and track the workpiece surface, the shoulder is stationary relative to the tool body, and the pin reciprocates relative to the shoulder to maintain contact with the backing plate, thereby providing a weld throughout the workpiece. In another embodiment, when the tool is used on an apparatus that holds the tool in fixed relationship to a backing plate on which the workpiece is held, the shoulder is able to reciprocate relative to the tool, following the upper surface contours of the workpiece, while the pin is able to penetrate through to the rear side of the workpiece to produce a uniform weld.

Friction stir welding tool for welding variable thickness workpieces

A cutter body (22, 22') has a slot (26, 26') opening onto its nominal outer cylindrical surface (24) and extending along a plane that intersects the cutter axis (X) at an acute axial rake angle (A). A flat cutter blade insert (40) with an elliptical polycrystalline diamond cutting edge (48) is secured in the slot (26, 26'). The insert (40) is positioned to produce a non-negative radial rake at each point along the cutting edge (48). Preferably, the cutter (20, 20') has a plurality of circumferentially spaced slots (26, 26') and inserts (40). The slots (26') may be arranged in a herringbone pattern to resist delamination of a workpiece. Preferably, the cutter relief angle varies along the insert (40) from a minimum at the leading end (50) to a value at the trailing end (52) equal to the minimum plus the angle between the radial lines of the cylinder (24) through the leading and trailing ends (50, 52), respectively.

Cutter with angled diamond inserts

A method and apparatus for collecting dust and particles produced in machining a workpiece. The method and apparatus uses a shroud formed by a pair of frusta-conical walls spaced apart from each other to define an annular air passage therebetween. The shroud is mounted so that the machine tool extends through a central opening formed in the shroud. The annular air passage has an upper air inlet intersecting the air passage with a cylindrical component and a lower air outlet facing inwardly toward the machine tool. Pressurized air flows into the air passage and is thus directed from the air outlet toward the machine tool in a swirling manner. At the same time, a vacuum withdraws air from within the shroud to collect dust and chips produced by the machine tool.

Growing community of inventors

North Bend, WA, United States of America

Kevin James Colligan