Abstract: A method of joining a pair of metal components with a rivet having a hardness that is substantially similar to at least one of the metal components. The metal components are stack upon each other and the rivet is rotated and simultaneously plunged in the metal components under pressure to friction weld and metallurgically bond the rivet to the metal components.

Abstract: A cutting tool 60 cuts along the butted portion between two members 10, 20. A filling material 30 is inserted to the gap 40 formed by said cutting, and a roller 70 presses protrusions 12 and 22 to crimp said protrusions 12 and 22 so as to fix said filling material to position. Next, friction stir welding is performed to the protrusions 12, 22 and the filling material 30 using a rotary tool 80. In another example, instead of cutting, the filling material can be welded and filled to the gap. In yet another example, cutting can be performed so as to approximate the two members before performing the friction stir welding step.

Abstract: A method of joining tubular structures using friction welding is disclosed. The invention provides a method of joining a first tubular structure having a conical contact surface to a second tubular member with an elliptical contact orifice by placing the conical surface within the contact orifice, rotating one of the structures, and pressing them together to form a weld. The invention further discloses airbag inflators constructed using the method of the invention.

Abstract: A method for treating alloy before and after friction stir welding, the method comprising the following steps. First solution heat treating a multiplicity of aluminum-zinc alloy engineered components for a first time period at a first temperature. First air cooling the components in ambient air at room temperature until the components are cooled to room temperature. Friction stir welding the components to form an assembly. Second solution heat treating the assembly for a second time period at a second temperature. Additional steps and embodiments are considered.

Abstract: Two members 11 and 12 are butted against each other, and the butted portion is cut with a cutter 20 to form a slit 14 thereto, and a filler member 21 is inserted to slit 14 using rollers 22, 23 and 25. Then, friction stir welding is performed to weld filler member 21 and two member 11 and 12 disposed on both sides thereof using a rotary tool 35, and the position of a gap formed between an end of filler member 21 at the upstream side in the rotating direction of rotary tool 35 and one member 11b at the upstream side in the rotating direction is detected using an optical sensor 35. Then, half the width of filler member 21 is added to the detected position, and the calculated position is set as the position of the rotary tool 35.

Abstract: In a device for butt joining workpieces by friction stir welding along a connecting area, including a shaft having a driven end and, at the opposite end, a pin-like projection to be disposed in the connecting area of the workpieces, whereby, upon rotation of the shaft, the workpiece material in contact with the pin-like projection is plasticized, first and second stops with first and second shoulders are provided on the device and disposed at opposite sides of the workpieces and at least one of the stops is movable relative to the other and biased toward the other with a controllable force for engaging the workpieces between the shoulders of the stops during the friction stir welding procedure.

Abstract: Grooves 18 formed to face plates 11 and 12 of a hollow shape member 10 at an abutted region with hollow shape member 20 receive projections 28 formed to face plates 21 and 22 of member 20. A connecting plate 14 orthogonal to the face plates 11 and 12 is provided to the hollow shape member 10. There is no connecting plate orthogonal to face plates 21 and 22 disposed on the end of the hollow shape member 20. Friction stir welding heat causes the face plate 21(22) to wove toward the thickness direction of hollow shape members 10 and 20, but such movement is suppressed by the groove 18 and projection 28. Thereby, the abutted region is welded flatly.

Abstract: A laser-assisted friction stir welding method for joining workpieces, that includes the step of providing a side face for each workpiece between first and second workpiece surfaces, each side face shaped such that, in a pressed-together condition, the side faces touch each other at the second workpiece surface and are spaced from each other in a middle region of the side faces so that a gap exists between the side faces at the first workpiece surface. The method also includes pressing together the side faces so as to form a joint area, and advancing a welding probe, while the probe is in rotary motion, along the joint area at the first workpiece surface and irradiating workpiece material located in front of the welding probe using laser radiation so as to plasticize the workpiece material along the joint area. The method also includes removing the welding probe from the joint area before the workpiece material completely solidifies.

Abstract: A projection 3 is pressed into first and second members W1 and W2 with a predetermined pressure, while rotating a rotary tool 1 at a preset rotational speed, such that the first and second members W1 and W2 are sandwiched by the rotary tool 1 and stationary tool 10. The projection 3 rotates in these members to cut member textures around it, thereby generating heat. Furthermore, the cuttings formed by cutting with the projection 3 are accumulated in the members and agitated by the two tools 1 and 10, to collide against the surrounding member textures and the projection 3, thereby generating heat. Also, a first shoulder 2 is pressed in with a predetermined pressure and rotated to generate heat, thereby fusing the cuttings. While the plastic flow of the surrounding member textures is promoted, the first shoulder 2 is held at the predetermined pressure and rotational speed. The pressure per unit area is thus increased to increase the volume of plastic flow.

Abstract: An assembly, such as an aircraft component, is formed with a weld joint by, for example, using friction stir welding, FSW, to form a lap joint between a stiffer and the interior surface of the skin of the component. A sealant layer, such as a monomer sealant/adhesive is applied to the surfaces to be joined, and is cured in place by the elevated temperatures of the welding process to form an elastomeric fay surface sealing, such as a fluoroelastomeric coating, to protect the component from corrosion at the welds. Additional heat for curing may be applied by laser or induction heating or the like.

Abstract: The invention provides a friction stir welding apparatus and method and a processing apparatus and method, which are not easily affected by deformations of a work being processed. The friction stir welding apparatus inserts a rotating tool into the work and moves the rotating tool relative to the work to join members of the work. The friction stir welding apparatus and method and the processing apparatus and method of the invention, the latter cutting or grinding the work with a rotating cutter or grindstone, comprises controlling a relative distance between the tool, cutter or grindstone and the work under the joining or processing operation or an insertion depth so that the load factor or electric current of a spindle motor for rotating the tool, cutter or grindstone is within a predetermined range, and a controller therefor.

Abstract: On a main shaft 30 of a numeric control type machine tool, a rotary tool 50 is installed. The main shaft 30 is not inclined in the machine tool. A first member 70 and a second member 76 to be subjected to friction stir welding are fixed on a table 20. Relative to an axial center of the rotary tool 50, a non-linear welding portion of the first member 70 and the second member 76 is inclined by inclining the table 20. Then, by rotating the table 20 and relatively moving the portion to be welded into contact with the rotary tool 50, welding of the first member to the second member is carried out according to friction stir welding. The above-stated inclination is the inclination required for the friction stir welding. In this way, welding along a path of ring shape or circular shape (including a circular arc) using friction stir welding can be carried out easily.

Abstract: A rotary tool (200) having on the end surface of a large-diameter portion (210) facing a small-diameter portion (220) grooves (213) formed in arc-like shapes, and performing friction stir weld by inserting the end surface of the large-diameter portion (210) and the small-diameter portion to members and rotating the tool (200). By the rotation, the metal of the members moves along the grooves (213) to the center axis direction of the rotary tool (200). The arc-shaped grooves (213)are formed to curve toward the direction of rotation. Since the metal material of the members is moved toward the center, a good weld is realized even when only one of the members to be welded has a projection, or when a large gap is formed therebetween.

Abstract: The present invention provides an improved method and apparatus for joining aluminum allow panels (eg. 2090-T83 aluminum lithium alloy). The method preliminarily positions two panels and skin panels next to each other so that a stringer panel overlaps a skin panel. A friction stir weld pin tool penetrates through one panel and at least partially into another panel. The panel material around the pin tool is frictionally heated.

Abstract: A precipitation hardened structural assembly is provided, including a first structural member and a second structural member positioned adjacent to the first structural member such that the first and second structural members define an interface therebetween. At least one friction stir weld joint joins the first structural member to the second structural member at least partially along the interface. The first and second structural members and the friction stir weld joint are solution heat treated at a first predetermined temperature schedule and precipitation heat treated at a second predetermined temperature schedule and wherein the friction stir weld joint comprises a refined grain structure having grain size of less than about 5 microns.

Abstract: An apparatus and method for joining structural members to form preforms and structural assemblies are provided. The structural members are positioned so that joining surfaces thereof define an angled aperture, such a slot or frustoconical bore, that receives a corresponding joining member. The joining member is urged into the aperture against the joining surfaces and moved, for example, by oscillating or rotating the joining member, to friction weld the joining member to the structural members. Each structural member can include a clamping portion that is received by a clamping device that prevents the aperture from opening as the joining member is urged into the aperture. A gripping portion of the joining member and the clamping portions of the structural members can be trimmed from the resulting preform to form a finished structural assembly.

Abstract: A rim member 120 forming an entrance 110 and a plate 11 (21) are friction stir welded by moving a rotary tool 200 along the rim member 120. The rotary tool 120 is tilted along the direction of movement. Welding is started at right block 120R, and when the tool reaches corner portion P5 between the right block 120R and a center block 120C, the tool 200 is pulled out of the rim member 120 and plate 11 (21). Next, the tool is tilted toward the direction of movement along center block 120C. Thereafter, the tool is lowered and inserted to position, and friction stir welding is restarted. According to the invention, the direction of the rotary tool is not changed while the tool is inserted to the rim member 120. This prevents generation of excessive friction heat, and thereby realizes a good weld.

Abstract: Abutted portions of face plates 12b and 22b of frame members 10 and 20 are friction stir welded. With the abutting, a projecting portion 20c of an end portion of the face plate 20b of the frame member 20 is inserted into a recessed portion 12c of an end portion of the face plate 12b of the frame member 10. By this engagement, the outer face on one face side of the face plates 12b and 20b form a smooth surface, so that there is no step at the joined edges. Next, a rotary tool 250 is inserted into the gap between the abutted plates, from the side of the raised portions 16 and 26 of the face plates 12b and 20b, while the other faces 12bc and 20bc of the face plates 12b and 20b are supported flatly on a bed during the friction stir welding. Accordingly, the welding of the engaged plates can be carried out without any step-wise difference.

Abstract: A probe for friction stir welding MMCs, ferrous alloys, non-ferrous alloys, and superalloys, as well as non-ferrous alloys, the probe including a shank, a shoulder, and a pin disposed through the shoulder and into the shank, wherein the pin and the shoulder at least include a coating comprised of a superabrasive material, the pin and shoulder being designed to reduce stress risers, disposing a collar around a portion of the shoulder and the shank to thereby prevent movement of the shoulder relative to the shank, and incorporating thermal management by providing a thermal flow barrier between the shoulder and the shank, and between the collar and the tool.

Abstract: Friction stir processing (FSP) modifies the surface microstructure of metals so that thick-section metal workpieces can be bent over large angles without formation of surface cracks. A thick 2519-T8 aluminum plate (25.4 mm thick and 50.8 mm wide) was friction stir processed across the pre-tensile surface to a depth of 6.3 mm, and was then bent at room temperature over a punch with radius 38.1 mm into a v-shaped die to an 80° bend angle. Whereas unprocessed workpieces of this type exhibited surface cracking at 31° bend angle and failed at 40° bend angle, no cracking was evident for the friction stir processed workpiece up to 80° bend angle.

Abstract: The present invention relates to an improvement in the manufacture of metal blanks, discs, and sputtering targets by flattening only one of the two surfaces of a metal plate. The elimination of flattening the metal plate's second surface results in a significant cost reduction. The metal plate of the present invention preferably has a single-side flatness of 0.005 inches or less, which improves the reliability of the bond between the target blank and a backing plate. Preferred metals include, but are not limited to, tantalum, niobium, titanium, and alloys thereof. The present invention also relates to machining the first side of a metal plate, bonding the first side to a backing plate, and then optionally machining the second side of the metal plate.

Abstract: A raised portion 32 is provided on an upper face of an end portion of a plate 31 which forms one side of a frame member 30. An end portion of a plate 41 of another frame member 40 is abutted with the plate 31 of the frame member 30. The frame members 30 and 40 are aluminum alloy extruded frame members and the directions of extrusion of the two frame members are orthogonal. A welding padding is carried on an upper face of the plate 41 of the frame member 40. Under this condition, a rotary tool is inserted from above and a friction stir welding is carried out. Accordingly, the padding serves the same function on the plate 41 as the raised portion 32 on the plate 31, so that a good welding can be carried out.

Abstract: There are provided an apparatus and method for friction welding structural members. The apparatus includes a connected shank and probe. The probe defines an absorption surface and a cavity extending thereto. The absorption surface is configured to receive electromagnetic radiation from an electromagnetic radiation source such as a light source or RF generator. The radiation heats the probe, supplementing the heat generated by friction between the probe and the structural members, and thereby increasing the speed at which the probe can be used to frictionally weld the structural materials.

Abstract: Aspects of the present invention provide methods and apparatus for connecting two tubulars using a welding process with reduced inner diameter flash. The method includes connecting an end of a first expandable tubular to an end of a second expandable tubular using a welding process and reducing an inner diameter flash using a flash reducing device. In one embodiment, the flash reducing device is a plug disposed in the bore of the two tubulars. In another embodiment, the flash reducing device is a roller member. In a further embodiment, the flash reducing device is a rotating cutting member.

Abstract: A probe for friction stir welding MMCs, ferrous alloys, non-ferrous alloys, and superalloys, as well as non-ferrous alloys, the probe including a shank, a shoulder, and a pin disposed through the shoulder and into the shank, wherein the pin and the shoulder at least include a coating comprised of a superabrasive material, the pin and shoulder being designed to reduce stress risers, disposing a collar around a portion of the shoulder and the shank to thereby prevent movement of the shoulder relative to the shank, and incorporating thermal management by providing a thermal flow barrier between the shoulder and the shank, and between the collar and the tool.

Abstract: Different metallic materials are joined in such a manner that friction heat generated by fiction between a rotating probe made of a hard material and one of the metallic materials having a lower mechanical strength or a lower melting point than the other to effect plastic flow of the one material and the probe is inserted into a pit formed in a joint zone of the other material to fill the pit with the plastic flow material.

Abstract: Catalytic converter (2) includes a catalyst container (10) formed from a tubular blank (10′) and having a catalyst carrier, and a flange member (11) joined to the hollow member. The tubular blank (10′) is subjected to a spinning operation by forming roll or rolls (22A), to form the catalyst container (10) having a desired shape, and the opposed circumferential surfaces of the catalyst container (10) and flange member (11) are forced against each other by the forming roll or rolls (22A) or an array of presser pieces (22B) while the catalyst container and flange member are rotated relatively to each other, so that friction heat is generated for friction-welding the catalyst container and flange member at their joining portions (10b, 11b).

Abstract: A method for friction stir welding using liquid cooling. The method includes the steps of moving a pin tool across a welding location, spraying a cooling liquid in a localized manner from a cooling ring moving with the pin tool onto a trailing region and onto lateral regions of the welding location adjacent to the pin tool, and blowing cooling gas from a gas jet moving with the pin tool from a front of the pin tool against the pin tool and against the cooling liquid emerging from the cooling ring. In addition, a friction stir welding and cooling device includes a pin tool configured to move across a welding location and a cooling ring at least partially encircling the pin tool. The cooling ring is configured to move simultaneously with the pin tool across the welding location and includes a plurality of nozzles configured to spray a cooling liquid.

Abstract: In a method and apparatus for joining at least two work pieces by friction stir welding wherein the work pieces are at least partially plasticized in the area where they are to be joined by a rotating friction tool provided with a projection which can be moved into the area of the joint to be formed, the projection on the rotating tool has a length corresponding about to the thickness of the work piece and a shoulder around the pin-like projection so that, upon movement of the tool toward the work pieces, the work piece material is plasticized by the rotating pin-like projection which moves into the work piece material until it reaches the surfaces of the lowermost

Abstract: A method of joining a pair of metal components with a rivet having a hardness that is substantially similar to at least one of the metal components. The metal components are stack upon each other and the rivet is rotated and simultaneously plunged in the metal components under pressure to friction weld and metallurgically bond the rivet to the metal components.

Abstract: A weld across a joint is formed between superposed plate workpieces comprising a first plate workpiece made up of one or more plates and a second plate workpiece made up of a single plate having a joint bore formed therein by grasping the superposed plate workpieces between a rotating friction agitation welding tool and a back-up tool, rotating and advancing the friction agitation welding tool toward the back-up tool in an axis of welding to force the friction agitation welding tool to penetrate into the first plate workpiece while urging the friction agitation welding tool and the first plate workpiece together whereby generating frictional heat to plasticize workpiece material around the friction agitation welding tool and cramming a plasticized workpiece material into the joint bore of the second plate workpiece and allowing the plasticized workpiece material to solidify.

Abstract: A body member and flange members are butted together at first and second abutment portions, and are retained by first and second backing jigs. In this arrangement, inner circumferential surfaces of the first and second abutment portions are fitted on and in close contact with outer circumferential surfaces of the first and second backing jigs. Subsequently, the friction stir welding is performed along each of the first abutment portion and the second abutment portion by using a probe which is rotated at a high speed.

Abstract: A body member and flange members are butted together at a first abutment portion and a second abutment portion. The first and second abutment portions are held by first and second backing jigs, respectively. The first backing jig has a circumscribing recessed section corresponding to an inner circumferential surface of the first abutment portion. Further, the first backing jig has a circumscribing opening communicated with the bottom of the recessed section. On the other hand, the second backing jig has a circumscribing recessed section corresponding to an inner circumferential surface of the second abutment portion. Further, the second backing jig has a circumscribing opening communicated with the bottom of the recessed section. First and second buffer members are attached to the recessed sections, respectively.

Abstract: The method comprises introducing a tip of a solid phase welding tool between adjacent surfaces of a crack formed in an aircraft skin. The tool is then operated to produce a friction stir weld so as to weld the adjacent surfaces together and thereby repair the crack. Apparatus for performing the method comprises a base having carriage thereon, the arm being pivotally mounted on the carriage and supporting the friction stir welding tool. The position of an arm can be adjusted by a screw which drives the rotating tip of friction stir welding tool into the crack to be repaired. The carriage is then moved along the base to draw the tip along the crack. The apparatus is portable and is particularly useful for repairing a cracked skin on an aircraft.

Abstract: A probe for friction stir welding MMCs, ferrous alloys, non-ferrous alloys, and superalloys, as well as non-ferrous alloys, the probe including a shank, a shoulder, and a pin disposed through the shoulder and into the shank, wherein the pin and the shoulder at least include a coating comprised of a superabrasive material, the pin and shoulder being designed to reduce stress risers, disposing a collar around a portion of the shoulder and the shank to thereby prevent movement of the shoulder relative to the shank, and incorporating thermal management by providing a thermal flow barrier between the shoulder and the shank, and between the collar and the tool.

Abstract: In the friction agitation joining method according to the present invention, two plate-shaped joining members different in thickness, or a first joining member (1) and a second joining member (2), are butted against each other with a level difference formed at upper surface sides thereof. A rotating probe (42) of the joining tool (40) is inserted into the butted portion (3) of said first and second joining members (1,2) from the upper surface sides thereof. Joining-direction front sides of the first joining member (1) and the second joining member (2) with respect to the probe inserted position is pressed by a first front pressing roller (11) and a second front pressing roller (11), respectively, from the upper surface sides thereof.

Abstract: A system and associated friction stir welding (FSW) assembly, controller and method for performing a friction stir welding operation are provided. The friction stir welding system includes a FSW device, such as a CNC machine, that includes an actuator capable of moving a FSW tool relative to a workpiece. The system also includes a controller capable of controlling the FSW device to drive the actuator to move the FSW tool. In this regard, the actuator is capable of being driven such that the FSW tool is capable of performing a friction stir welding operation on the workpiece. The controller is capable of monitoring a torque of the actuator to thereby control the FSW device to drive the actuator such that the torque is maintained within a range about a torque setting.

Abstract: A friction stir rivet is rotated and driven through a first fusible workpiece into an engaged second fusible workpiece, causing local portions of the first and second workpieces to plasticize. A slideable cap contacts the exposed surface of the first workpiece shortly after the process begins. The contact causes the cap to act as a retaining element, limiting the escape of plasticized material from stir site. Once the rivet is driven into the first and second workpieces, rotation ceases and the plasticized material hardens around the rivet. A weld is thus created, joining the workpieces and encompassing the rivet, which provides additional mechanical strength.

Abstract: A friction stir welding device that is configured to perform convention friction stir welding as well as self-reacting friction stir welding. A pin passes through an upper shoulder and can selectively attach to and detach from a lower shoulder in a preferred embodiment. A controller maintains the discrete position of, and/or force applied by, the upper and lower shoulders during self-reacting friction stir welding, or maintains the pin at a desired depth and/or applied force during conventional friction stir welding.

Abstract: A friction stir rivet is rotated in a precessing motion and driven through a first fusible workpiece into an engaged second fusible workpiece, causing local portions of the first and second workpieces to plasticize. When the rivet is driven through the first workpiece and into the second workpiece, rotation is stopped and the plasticized material solidifies around the rivet creating an enlarged weld joining the metal workpiece and encompassing the rivet, which provides additional mechanical strength.

Abstract: There is provided a method capable of decreasing a friction force in friction stir welding, in which a welding tool is used. In a method of friction stir welding workpieces together by rotating and pressingly plugging a welding tool, formed from a harder material than the workpieces, into a weld zone of the workpieces and moving the welding tool relatively in a welding direction, a power supply device allows a current to flow between the welding tool 1 and the workpieces to cause resistance heating of the welding tool. Combined use of resistance heating makes it possible to decrease a friction force. Preferably, a conductive ceramic is coated on surfaces of the welding tool to cause resistance heating.

Abstract: An apparatus and method for joining structural members to form preforms and structural assemblies are provided. The structural members are positioned so that joining surfaces thereof define an angled aperture, such a slot or frustoconical bore, that receives a corresponding joining member. The joining member is urged into the aperture against the joining surfaces and moved, for example, by oscillating or rotating the joining member, to friction weld the joining member to the structural members. Each structural member can include a clamping portion that is received by a clamping device that prevents the aperture from opening as the joining member is urged into the aperture. A gripping portion of the joining member and the clamping portions of the structural members can be trimmed from the resulting preform to form a finished structural assembly.

Abstract: A low temperature target and backing plate bonding process and assemblies made thereby. A plurality of projections are formed in the harder member of the assembly. The assembly is bonded by conventional techniques around the peripheral assembly boundaries. The assembly is then pressure consolidated at low temperature so that the projections, circumscribed by the bonded zone, penetrate into the softer member promoting the formation of metal to metal cold diffusion type bonds.

Abstract: A friction agitation joining tool (10A, 10B) includes a rotor (11) having an end portion to be pressed onto at least one of surfaces of joining members (11a, 1b) and a probe (13) to be inserted into a joining portion (3) of the joining-members (1a, 1b), wherein the probe (13) has a diameter smaller than a diameter of the rotor (11). An end face (12) of the end portion of the rotor (11) is formed into a concave surface dented from a periphery of the end face (12) toward a rotational center of the end face (12). The probe (13) is protruded from the rotational center of the end face (12). The end face (12) is provided with a spiral groove (15) or an annular groove (16) surrounding the probe (13). By performing the joining operation with the joining tool (10A, 10B), a joined member with a good joint can be obtained.

Abstract: Plural extrusion members 100, each having plural ribs 105 formed on one surface of a face plate 101, are mounted on a frame 40 with the surface not having the ribs 105 facing downward, and with the end regions of the adjacent members 100, 100 being butted to each other. Then, the end regions of said members 100 are welded using friction stir welding from the upper direction with a rotary body 20, and then a hairline finish is applied to said surface not having the ribs, which constitutes the exterior surface of the vehicle body. In this way, there is substantially no need to cut off the joint bead, which improves the appearance of the vehicle body and reduces the manufacturing cost.

Abstract: The method of manufacturing a structural assembly includes positioning a first structural member at least partially adjacent a second structural member to define an interface therebetween and inserting a rotating plug into the first and second structural members at the interface to thereby join the first structural member to the second structural member. The resulting friction plug weld provides a relatively strong joint between the structural members, requires less forming and machining time, and is compatible with single-sided tooling. Additionally, the friction plug weld is compatible with other joining methods, such as friction stir welding.

Abstract: Disclosed is a friction stir welding method for welding two members to be welded which differ in physical properties and/or mechanical properties by abutting the two members to each other, inserting a pin portion of a rotary tool having the pin portion and a shoulder portion to the abutment surfaces of the two members, and moving the rotary tool along the abutment surfaces. The pin portion is inserted to only one of the members, the pin portion is not inserted to the other of the members but only the shoulder portion is set in contact with the other of the members, and, while this condition is maintained, the rotary tool is moved. With this method, only the member on the side where the pin is inserted can be made to undergo plastic flow attendant on a friction stir action. The metal in plastic flow is pressed against the opposite member at an elevated temperature and high pressure, whereby diffusion of atoms is caused in the vicinity of the abutment surfaces, and the members are welded.

Abstract: A method of constructing a preform for use in forming a machined structural assembly is provided. The method includes determining the dimensions of the machined structural assembly. First and second structural members are selected based on the predetermined dimensions of the machined structural assembly. The first structural member is positioned adjacent the second structural member so as to define at least two contact surfaces. The contact surfaces of the first and second structural members are friction welded to construct the preform such that the preform has dimensions approximating the dimensions of the machined structural assembly to thereby reduce material waste when forming the machined structural assembly. A machined structural assembly having predetermined dimensions is formed from the preform by machining away excess material.

Abstract: The present invention relates to rotary friction welding and non-rotary motion friction welding, providing means for controlling ductilities of the components during the welding process so as to bias the welding process in favor of a first component or to match the ductilities of different components thereby facilitating the welding process.

Abstract: A raised portion 32 is provided on an upper face of an end portion of a plate 31 which forms one side of a frame member 30. An end portion of a plate 41 of another frame member 40 is abutted with the plate 31 of the frame member 30. The frame members 30 and 40 are aluminum alloy extruded frame members and the directions of extrusion of the two frame members are orthogonal. A welding padding is carried on an upper face of the plate 41 of the frame member 40. Under this condition, a rotary tool is inserted from above and a friction stir welding is carried out. Accordingly, the padding serves the same function on the plate 41 as the raised portion 32 on the plate 31, so that a good welding can be carried out.