Abstract: In a friction agitation joining method, two plate-shaped joining members different in thickness, or first and second joining members, are abutted against each other with a level difference formed at upper surface sides thereof. A rotating probe of a joining tool is inserted into the butted portion of the first and second joining members from upper surface sides thereof. Joining-direction front sides of the first and second joining members with respect to the probe inserted position are pressed by first and second front pressing rollers, respectively, from the upper surface sides thereof. Furthermore, joining-direction lower sides of the first and the second joining members with respect to a probe inserted position from the upper surface sides are pressed by first and second lower pressing rollers, respectively, from the upper surface sides thereof. In this state, the butted portion is joined by the friction agitation joining method.

Abstract: A joined structure has high strength, which is used for manufacturing a joint made from different metal materials. In the joined structure in which the different metal materials are joined, a reaction product layer to be generated on the joined interface is set to have a thickness of 0.5 &mgr;m or less. Moreover, the reaction product layer is allowed to intermittently exist on the joined interface. Furthermore, the reaction product layer contains a base material crystal consisting of base material atoms of 90 atom % or more on the joined interface.

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 friction stir welding method conducts contact welding on two welding target members having different high temperature deformation resistances by using a welding tool having a rotatable welding head, contacting the two welding target members having different high temperature deformation resistances against each other so as to generate a difference in height between the two welding target members on a surface side in a thickness direction, arranging the rotating head in a state in which the head is embedded into a contact section of the two welding target members or a neighborhood of the contact section from the surface side, and relatively moving the welding head to the two welding target members along the contact section in this state, is provided.

Abstract: An aluminum extrusion material for hydraulic bulge forming, which can produce hydraulic bulge forming components possessing highly reliable and sufficient strength and rigidity capable of withstanding not only a static load, but also a twist load and dynamic load is provided. Also provided is a hydraulic bulge forming method using the aluminum extrusion material for hydraulic bulge forming as a raw material. The aluminum extrusion material is hollow and used as a material for hydraulic bulge forming. The material is characterized by having a partition wall radially crossing the hollow part of the extrusion material, wherein the partition wall is provided with an allowance in length to become flat when the hollow part is formed into a prescribed shape by hydraulic bulge forming.

Abstract: A joined structure has high strength, which is used for manufacturing a joint made from different metal materials. In the joined structure in which the different metal materials are joined, a reaction product layer to be generated on the joined interface is set to have a thickness of 0.5 &mgr;m or less. Moreover, the reaction product layer is allowed to intermittently exist on the joined interface. Furthermore, the reaction product layer contains a base material crystal consisting of base material atoms of 90 atom % or more on the joined interface.

Abstract: An electrically conductive fuse element including fusible portions has a hinge portion provided at a middle portion thereof. A resin body is divided into resin body parts so that the resin body parts are provided around the fuse element in such a way as to be separated by the hinge portion. One of the resin body parts is bent from the hinge portion. The fuse element has abutting faces, against which the resin body parts are abutted in a bent state, and engaging means for the resin body parts. A connector housing is provided on the resin body part. Further, a terminal is provided at one of plate portions of the fuse element. Power supply connecting portions and terminal connecting portions are provided in the other plate portion connected to the plate portion through the hinge portion.

Abstract: An electrically conductive fuse element including fusible portions has a hinge portion provided at a middle portion thereof. A resin body is divided into resin body parts so that the resin body parts are provided around the fuse element in such a way as to be separated by the hinge portion. One of the resin body parts is bent from the hinge portion. The fuse element has abutting faces, against which the resin body parts are abutted in a bent state, and engaging means for the resin body parts. A connector housing is provided on the resin body part. Further, a terminal is provided at one of plate portions of the fuse element. Power supply connecting portions and terminal connecting portions are provided in the other plate portion connected to the plate portion through the hinge portion.