According to an aspect of the disclosure, there may be provided a peening apparatus for generating a compressive residual stress on a pipe member including at least one curved round portion and having a hollow inside formed therein in which a first fluid and a second fluid, which is in a gas phase, are accommodated, the apparatus including: a probe which is disposed such that it is submerged in the first fluid supplied to the hollow inside, and which is configured to apply a wave to the first fluid, wherein the first fluid and the second fluid have different acoustic impedances, so that the wave is totally reflected on a reflection surface where the first fluid and the second fluid are in contact, and forms a standing wave, and wherein a cavity generated and grown by the formed standing wave is exploded and emits a shock wave or microjet, which generates a compressive residual stress on the inner surface of the pipe member surrounding the hollow inside.

An electrohydraulic forming device comprising includes a tank having a tank inner wall and inside of which are positioned a mold, a first electrode, and a second electrode. A free first reflector is placed in the tank and surrounds the mold, the first electrode, and the second electrode.

A method for forming or deforming a workpiece at a high speed using electroplasticity effect includes: applying a first level of pulse current to the work piece to cause the electroplasticity effect and lower a flow stress of the work piece; and applying a first level of electromagnetic force to the workpiece for 150˜300 μs to form or deform the work piece in a desired shape while the flow stress of the work piece is maintained at the lowered level, wherein the first level of electromagnetic force is lower than a second level of electromagnetic force which is required to form or deform the workpiece in the desired shape without applying the first level of pulse current.

A method for forming or deforming a workpiece at a high speed using electroplasticity effect includes: applying a first level of pulse current to the work piece to cause the electroplasticity effect and lower a flow stress of the work piece; and applying a first level of electromagnetic force to the workpiece for 150˜300 μs to form or deform the work piece in a desired shape while the flow stress of the work piece is maintained at the lowered level, wherein the first level of electromagnetic force is lower than a second level of electromagnetic force which is required to form or deform the workpiece in the desired shape without applying the first level of pulse current.

A method of manufacturing a part includes additively manufacturing, with an additive manufacturing machine, at least one wall of the part having a first thickness from powder in a powder bed, and peening, with a peening system, at least a portion of the wall of the part. The peening induces plastic deformation in the portion of the wall. The portion of the wall that is peened has a second thickness less than the first thickness of the wall prior to peening. The second thickness of the portion of the wall may be less than a minimum thickness limit achievable by the additive manufacturing machine.

A method of manufacturing a part includes additively manufacturing, with an additive manufacturing machine, at least one wall of the part having a first thickness from powder in a powder bed, and peening, with a peening system, at least a portion of the wall of the part. The peening induces plastic deformation in the portion of the wall. The portion of the wall that is peened has a second thickness less than the first thickness of the wall prior to peening. The second thickness of the portion of the wall may be less than a minimum thickness limit achievable by the additive manufacturing machine.

An electrohydraulic forming device includes a tank having a tank inner wall and inside of which are positioned a mold, a first electrode, and a second electrode. A free first reflector is placed in the tank and surrounds the mold, the first electrode, and the second electrode.

An electrohydraulic forming device includes a tank having a tank inner wall and inside of which are positioned a mold, a first electrode, and a second electrode. A free first reflector is placed in the tank and surrounds the mold, the first electrode, and the second electrode.

A method for welding a stack of sheets having a plurality of sheets of different materials is provided. In an aspect, the stack of sheets includes an aluminum sheet and a galvanneal steel sheet. In an aspect, the method includes resistively spot welding the galvanneal sheet to a hot-stamped steel sheet placed between the aluminum sheet and the galvanneal sheet, the sheet of hot-stamped steel including stress relief sections. The method further includes placing a metal foil on the aluminum sheet and vaporizing the metal foil to project portions of the aluminum sheet through the stress relief sections of the hot-stamped steel sheet to weld the portions of the aluminum sheet to the galvanized steel sheet. In another aspect, the method includes placing the metal foil on a raised portion of the aluminum sheet and projecting the raised portion of the aluminum onto the galvanneal steel sheet.

A method for controlling a superplastic forming machine for imprinting a shape on a sheet, the machine comprising: a cover; a vat; a press and a peripheral seal for gripping the sheet at its periphery and sealing a pressurized forming chamber delimited by the sheet; members for heating the sheet directly by radiation, these being arranged facing the sheet; a programmable controller. The method involves: determining an initial heating configuration; a finite-element simulation relating to the temperature of the sheet and performed in such a way as to have a temperature that is substantially consistent across the sheet and substantially constant during the course of the forming, in order to obtain a forming specification comprising at least a cycle of powering the heating members and a cycle of pressure in the forming chamber; programming the programmable controller according to the forming specification yielded by the previous simulation.