A first member and a second member are formed of metal materials of the same type and a third member is formed of a material of a different type that is difficult to weld to the first member and the second member. The first member and the second member are welded to each other via a through hole with the third member interposed therebetween in a region corresponding to a first protrusion. For the first member and the third member, and the second member and the third member, each of respective outer peripheral portions of an overlapping portion of the first member and the third member and an overlapping portion of and the second member and the third member is welded.

While a laser-beam application position is moved along a locus which circularly or elliptically circles around a locus center so as to cross a weld line that is a boundary between a first metal plate and a second metal plate overlapped with each other, the locus center is moved in a direction parallel to a weld line. A moving direction of the laser-beam application position is set such that the laser beam is first applied to the first metal plate and then to the second metal plate when the laser beam passes through an unmelted zone of the first metal plate and the second metal plate. The unmelted zone is located downstream of a range through which the laser beam has already passed in the direction parallel to the weld line.

While a laser-beam application position is moved along a locus which circularly or elliptically circles around a locus center so as to cross a weld line that is a boundary between a first metal plate and a second metal plate overlapped with each other, the locus center is moved in a direction parallel to a weld line. A moving direction of the laser-beam application position is set such that the laser beam is first applied to the first metal plate and then to the second metal plate when the laser beam passes through an unmelted zone of the first metal plate and the second metal plate. The unmelted zone is located downstream of a range through which the laser beam has already passed in the direction parallel to the weld line.

A laser welding head with movable mirrors may be used to perform welding operations, for example, with wobble patterns and/or seam finding/tracking and following. The movable mirrors provide a wobbling movement of one or more beams within a relatively small field of view, for example, defined by a scan angle of 1-2. The movable mirrors may be galvanometer mirrors that are controllable by a control system including a galvo controller. The laser welding head may also include a diffractive optical element to shape the beam or beams being moved. The control system may also be used to control the fiber laser, for example, in response to the position of the beams relative to the workpiece and/or a sensed condition in the welding head such as a thermal condition proximate one of the mirrors.

A laser welding head with movable mirrors may be used to perform welding operations, for example, with wobble patterns and/or seam finding/tracking and following. The movable mirrors provide a wobbling movement of one or more beams within a relatively small field of view, for example, defined by a scan angle of 1-2. The movable mirrors may be galvanometer mirrors that are controllable by a control system including a galvo controller. The laser welding head may also include a diffractive optical element to shape the beam or beams being moved. The control system may also be used to control the fiber laser, for example, in response to the position of the beams relative to the workpiece and/or a sensed condition in the welding head such as a thermal condition proximate one of the mirrors.

A feed axis motor includes a front-side housing fixed to an end face of a stator core. The stator core is formed of a material with iron as a main component. The front-side housing is formed of a material with aluminum as a main component. The stator core and the front-side housing are coupled with each other at a welding mark generated by laser welding. The welding mark extends in a circumferential direction so as to cover a line of contact between the stator core and the front-side housing. The welding mark seals the boundary portion between the stator core and the front-side housing.

A method of manufacturing an airfoil includes creating a plurality of cavities separated by a plurality of internal ribs in an airfoil forging. At least one hole is drilled in at least one of the plurality of internal ribs with a waterjet drilling tool. At least one hole extends perpendicularly to a wall of the rib.

A joint structure comprising a light-absorbable member having at least one opening portion and a light-permeable member superposed on the light-absorbable member so as to cover the opening portion, wherein an annular weld part is formed so as to enclose the opening portion and join the light-absorbable member and the light-permeable member, and an area ratio of a portion at the side of the light-absorbable member to a portion at the side of the light-permeable member side is in a range of 12-35 viewing a section perpendicular to the extending direction of the annular weld part.

A joint structure comprising a light-absorbable member having at least one opening portion and a light-permeable member superposed on the light-absorbable member so as to cover the opening portion, wherein an annular weld part is formed so as to enclose the opening portion and join the light-absorbable member and the light-permeable member, and an area ratio of a portion at the side of the light-absorbable member to a portion at the side of the light-permeable member side is in a range of 12-35 viewing a section perpendicular to the extending direction of the annular weld part.

A stator of an electric rotary machine includes: a stator core; and a coil including a plurality of first coil segments and a plurality of second coil segments. An end part of the projection part of the first coil segment is joined with an end part of the projection part of the second coil segment through laser welding in a state of abutting to the end part of the projection part of the second coil segment. And abutting portions abutting to each other between the projection part of the first coil segment and the projection part of the second coil segment include joining surfaces joined with each other and engaging surfaces engaged with each other and orthogonal to the joining surfaces.