A method for forming a metal matrix composite (MMC) structure includes forming an assembly including at least two blocks of a primary phase material sharing an interface at which a secondary phase material is disposed. The assembly has a length, a width, and a thickness. The method also includes clamping the assembly to at least one of urge the at least two blocks toward each other or maintain the at least two blocks at a predetermined position. Also, the method includes passing a rotating friction-stir pin along the interface from the front edge to the rear edge. The friction-stir pin has a mixing length extending at least the width of the assembly, and passing the friction-stir pin along the length of the assembly disperses the secondary phase material into the primary phase material and welds the at least two blocks together.

Disclosed herein are systems, methods, and devices for repairing holes in weld seams created by bobbin friction stir welding tools. A hole may be created when a welding tool or, more specifically, a pin of the tool is removed or otherwise extracted from a weld seam created by the tool. The method may involve inserting a plug (e.g., a rivet) into the hole, reshaping the plug in the hole (e.g., riveting) thereby securing the plug in the component, and creating another weld seam through the plug thereby consuming the plug. In some embodiments, the hole may be reshaped prior to inserting the plug. For example, the hole may be drilled out and/or a countersink may be created on one or both ends of the hole. Furthermore, the plug may extend outside of the hole prior to its reshaping and, in some embodiments, even after reshaping.

A corrosion barrier for use under heads of a plurality of friction elements in a structural assembly and a method of installing the corrosion barrier are provided. The corrosion barrier defines a plurality of spaced apertures extending along a length of the corrosion barrier and a corresponding plurality of perforations concentrically located around the spaced apertures. A plurality of friction elements within a corresponding plurality of spaced apertures in a corrosion barrier forms a friction element strip assembly that is loaded into two workpieces. The two workpieces are joined together after an area of corrosion barrier is removed.

In the present disclosure, friction stir welding tools having probes and stationary shoulders are disposed at corners between a first workpiece and a second workpiece. A welding device main body includes axially perpendicular movement units for moving spindle units, which hold the respective friction stir welding tools on a frame, in directions perpendicular to rotary shafts of probes, and axial movement units for moving the spindle units in directions parallel to the rotary shafts of the probes.

A joining method for joining a first metal member with a second metal member with use of a rotary tool having a stirring pin is provided. The joining method includes steps of: butting the first metal member with the second metal member to form a butted portion; arranging an auxiliary member to be in surface-contact with the first metal member or the second metal member; and frictional stirring the butted portion in which the rotating stirring pin is inserted from a front surface of the auxiliary member and the rotary tool is relatively moved in the butted portion to join the first metal member, the second metal member and the auxiliary member, in the state that only the stirring pin is brought in contact with the first metal member, the second metal member and the auxiliary member.

The invention relates to a method for joining two essentially metal sheet-type workpieces. In said method, edge regions of the workpieces to be joined are bent by up to 90 in relation to a plane of the workpiece, the bent edge regions being placed against each other, and the edge regions are then heated to a predefined joining temperature by at least one first frictional element that moves relative to the edge regions, are subjected to a certain contact pressure, and are joined while being deformed.

A piston for an internal combustion engine has a surface treatment portion on a piston base material at a piston crown surface, the surface treatment portion including, along the direction of depth from the surface side, a first layer that is comprised of a layer of a first metal or a layer containing the first metal, a second layer that contains both a second metal containing oxygen or an oxide of the second metal and a low-thermal-conductivity material, and a third layer that is comprised of a mixture of a third metal and the low-thermal-conductivity material.

Solid-state joining of preformed features, such as bosses, flanges, gaskets, centralizers and other features to substrates or cast parts by a solid-state MELD additive manufacturing process is disclosed. Joining can be between same or different materials using same, similar or dissimilar filler material than the materials of the feature and the part that need to be joined.

A rotating tool system attachment on the spindle of a computer numerical control (CNC) machine includes a rotating assembly mounted on a static assembly. The rotating assembly provides a continuous supply of a wire material for deposition on a substrate during an additive manufacturing process. The rotating assembly includes a material supply housing a feedstock of wire mounted on a rotating spindle and a wire feeder configured to draw the wire from the wire supply and provide the wire for application during the additive manufacturing process. The tool system can be attached to the spindle of CNC machine to provide additive manufacturing capabilities to the CNC machine.

Concave part is formed in a crown surface of the top of piston made of an aluminum alloy. This concave part is filled with mixed powder constituted of zirconia powder as a filler material and pure aluminum powder as a bonding material. Solid cylindrical rotary implement is brought into contact with concave part filled with mixed powder, and then pressed against piston under load while being rotated. Mixed powder is softened by frictional heat with rotary implement, whereby mixed powder is bound in a solid phase to concave part to form low thermal conductive part. With this, the bonding strength of low thermal conductive part to the crown surface of the top of the piston is improved.