A welding method includes: forming one or more lower plate grooves having a predetermined width and a predetermined depth at one side of an upper surface of a lower plate; forming one or more upper plate grooves having a predetermined width and a predetermined depth at one side of a lower surface of an upper plate; overlapping the lower plate and the upper plate so that the lower plate grooves of the lower plate and the upper plate grooves of the upper plate mesh with one another; and performing welding to form a bead at a welding part.

A welding method includes: forming one or more lower plate grooves having a predetermined width and a predetermined depth at one side of an upper surface of a lower plate; forming one or more upper plate grooves having a predetermined width and a predetermined depth at one side of a lower surface of an upper plate; overlapping the lower plate and the upper plate so that the lower plate grooves of the lower plate and the upper plate grooves of the upper plate mesh with one another; and performing welding to form a bead at a welding part.

A metal member includes a first plate, and a second plate abutting against and welded to the first plate in at least one butt portion. In the butt portion, a length from a first end to a second end of a welding boundary line between the first plate and the second plate is longer than a length of a straight line connecting the first end to the second end of the welding boundary line.

A metal member includes a first plate, and a second plate abutting against and welded to the first plate in at least one butt portion. In the butt portion, a length from a first end to a second end of a welding boundary line between the first plate and the second plate is longer than a length of a straight line connecting the first end to the second end of the welding boundary line.

An electric cable includes a terminal, and a manufacture method thereof is to suppress shedding of wire strands from a core wire. The electric cable with terminal includes an end of an electric cable connected to the terminal. The electric cable includes a core wire that is a bundle of a plurality of wire strands. The terminal includes a connection portion in which the core wire is exposed at the end of the electric cable. The core wire is placed on the connection portion including a welded portion that is to be ultrasonic welded to the connection portion. The welded portion includes a high compression portion in which the core wire is compressed, and a low compression portion in which a position that is closer than the high compression portion to the end of the core wire is compressed at a compression lower than that of the high compression portion.

An electric cable includes a terminal, and a manufacture method thereof is to suppress shedding of wire strands from a core wire. The electric cable with terminal includes an end of an electric cable connected to the terminal. The electric cable includes a core wire that is a bundle of a plurality of wire strands. The terminal includes a connection portion in which the core wire is exposed at the end of the electric cable. The core wire is placed on the connection portion including a welded portion that is to be ultrasonic welded to the connection portion. The welded portion includes a high compression portion in which the core wire is compressed, and a low compression portion in which a position that is closer than the high compression portion to the end of the core wire is compressed at a compression lower than that of the high compression portion.

A method of welding a component made from a ferrous alloy to a component made from an aluminum alloy includes machining and cleaning a fay surface on the ferrous alloy component, machining and cleaning a fay surface on the aluminum alloy component, depositing a layer of copper alloy material onto the fay surface of the ferrous alloy component, forming a weld groove on at least one of the layer of copper alloy material deposited on the fay surface of the ferrous alloy component and the fay surface of the aluminum alloy component, and laser welding the layer of copper alloy deposited on the fay surface of the ferrous alloy component and the fay surface of the aluminum alloy component to one another.

A machine component includes a first region having a first linear expansion coefficient, and a second region having a second linear expansion coefficient greater than the first linear expansion coefficient and joined to the first region. A region including an outer periphery of an interface between the first region and the second region is inclined toward the second region side over the entire periphery. On a surface of the first region, a groove is formed to extend along the outer periphery of the interface.

A tube assembly includes at least first and second tubes configured for coupling at respective ends. The first and second tubes each include a base material, and a weld interface at the respective end. The weld interface is proximate to an inner diameter and an outer diameter of the first and second tubes, and includes a weld interface segment extending therebetween. A work hardened weld assembly couples the base material of each of the first and second tubes. The work hardened weld assembly includes a weld fusion zone between the weld interfaces of the first and second tubes and the weld interface segments of the first and second tubes. The weld fusion zone is work hardened and at least the weld interface segments of the first and second tubes are work hardened between the work hardened weld fusion zone and the base material of the first and second tubes.

A method of manufacturing a joining apparatus includes: providing a first metal member including an opening and a joint structure; providing a second metal member including an outer circumferential wall capable of contacting an inner circumferential wall that surrounds the opening and a joined structure, to which the joint structure is joined; causing the first metal member and the second metal member to move relative to each other, bringing one of a first joining section, which is configured by the inner circumferential wall and the outer circumferential wall, and a second joining section, which is configured by the joint structure and the joined structure, into contact, and separating the other joining section; starting energization between the first and the second metal members; bringing components of the other joining section into contact with each other; and joining the first and second joining sections by the relative movement and the energization.