A method utilizing cold welding to prepare grain boundaries having different included angles includes using a device including a support member. Two bent members are arranged opposite to each other in the support member. One ends of the two bent members are both fixedly connected to the support member, one end, away from the support member, of any bent member is fixedly connected to a first sample, one end, away from the support member, of the other bent member is fixedly connected to a second sample, and the first sample and the second sample are arranged corresponding to each other. The bent member includes a first metal sheet and a second metal sheet having different thermal expansion coefficients. An angle between the first sample and the second sample during butt welding can be controlled by changing an included angle of a bimetallic sheet.

A method for manufacturing a shaft (1) in which linking members (3) are provided to ends of a cylindrical member (2) including: polishing end surfaces of a metal sheet; a bending step for bending the metal sheet into a cylindrical or arcuate shape; butting together the polished end surfaces of the metal sheet, the end surfaces facing each other in a state in which the metal sheet has been bent into the cylindrical shape, or disposing a plurality of the metal sheets that are bent into an arcuate shape so as to form a cylindrical shape and butting together the polished end surfaces of the metal sheets, and then heating the butted portions so that the butted portions are diffusion-joined, thereby forming the cylindrical member (2); cooling the post-diffusion-joining-step cylindrical member (2); and joining the linking members (3) to the ends of the cylindrical member (2).

A welding method of a diffusion bonded structure in which the diffusion bonded structure formed by diffusion bonding metal parts to each other is bonded to another part by fusion welding includes a buffer layer forming step of forming a buffer layer in a welding region including a diffusion bonded joint of the diffusion bonded structure, the buffer layer having greater ductility than the diffusion bonded joint, and a welding step of bonding the welding region in which the buffer layer is formed to the another part by performing the fusion welding from above the buffer layer.

To provide a fitting member, an annular member, a joined member and a method of manufacturing the joined member, which prevent occurrence of a not-joined portion. A fitting member 10 has a fitting protrusion 10p which is protruded outward on an outside face 10s. An annular member 20 contains a space 20h in which the fitting member 10 is to be fitted. An annular member 20 has an annular protrusion 20p on an inside face 20f. When the fitting member 10 is fitted into the space 20h at a predetermined depth, the fitting protrusion 10p and the annular protrusion 20p fill not-joined portions which may be generated assuming that they are not provided. A joined member 30 is produced by fitting the fitting member 10 into the space 20h at the predetermined depth, so that a contact portion between the fitting member 10 and the annular member 20 is joined in solid phase.

The cold pressure welding apparatus includes a first holding part capable of sandwiching a first flat conductor, a second holding part disposed opposite to the first holding part and capable of sandwiching a second flat conductor, and a drive part for moving the first holding part and the second holding part. The drive part can move the first holding part and the second holding part between a first direction separated position and a close position along a first direction. The drive part can move the first holding part and the second holding part between a second direction separated position and a sandwiching position along a second direction.

A process for joining steel plate includes providing a steel plate and joining the steel plate to another material. The steel plate includes at least one surface having an Al—Si coating. The step of joining the steel plate to another material is performed while the steel plate is in an as- coated condition. Joining is performed using a forging process.

The cold pressure welding apparatus includes a first holding part capable of sandwiching a first flat conductor, a second holding part disposed opposite to the first holding part and capable of sandwiching a second flat conductor, and a drive part for moving the first holding part and the second holding part. The drive part can move the first holding part and the second holding part between a first direction separated position and a close position along a first direction. The drive part can move the first holding part and the second holding part between a second direction separated position and a sandwiching position along a second direction.

A joint unit includes a first metal pipe, a second metal pipe, and a joint portion (a region including a joint interface at which the end faces of the first and second metal pipes are joined to each other. At the joint portion, an outer circumferential bead portion protruding toward the outer circumference side and an inner circumferential bead portion protruding toward the inner circumference side are formed. The difference between the width of the outer circumferential bead portion (the width L1 of a grinding portion and the width L2 of the inner circumferential bead portion in a direction from the first metal pipe toward the second metal pipe is equal to or smaller than 40% with respect to the average value of the width L1 of the outer circumferential bead portion and the width L2 of the inner circumferential bead portion.

Dual alloy turbine rotors and methods for manufacturing the same are provided. The dual alloy turbine rotor comprises an assembled blade ring and a hub bonded to the assembled blade ring. The assembled blade ring comprises a first alloy selected from the group consisting of a single crystal alloy, a directionally solidified alloy, or an equi-axed alloy. The hub comprises a second alloy. The method comprises positioning a hub within a blade ring to define an interface between the hub and the blade ring. The interface is a non-contacting interface or a contacting interface. The interface is enclosed by a pair of diaphragms. The interface is vacuum sealed. The blade ring is bonded to the hub after the vacuum sealing step.

A method utilizing cold welding to prepare grain boundaries having different included angles includes using a device including a support member. Two bent members are arranged opposite to each other in the support member. One ends of the two bent members are both fixedly connected to the support member, one end, away from the support member, of any bent member is fixedly connected to a first sample, one end, away from the support member, of the other bent member is fixedly connected to a second sample, and the first sample and the second sample are arranged corresponding to each other. The bent member includes a first metal sheet and a second metal sheet having different thermal expansion coefficients. An angle between the first sample and the second sample during butt welding can be controlled by changing an included angle of a bimetallic sheet.