A surface treatment method includes: a first step of applying a plane wave-shaped shock wave to a workpiece to cause high-density transition to occur in a material structure of the workpiece; and a second step of applying a spherical wave-shaped shock wave or a pressure due to physical contact to the workpiece after the first step for plastic deformation of the workpiece.

A surface treatment method includes: a first step of applying a plane wave-shaped shock wave to a workpiece to cause high-density transition to occur in a material structure of the workpiece; and a second step of applying a spherical wave-shaped shock wave or a pressure due to physical contact to the workpiece after the first step for plastic deformation of the workpiece.

The invention relates to a method and a device for strengthening the surface of workpieces, in particular of metal ones, by mechanical effects accompanying the impact of small projectiles or by mechanical effects accompanied by the impact of a shockwave induced by plasma created by electric evaporation of a metal foil. The device comprises a polymer strip with a metal foil on the surface of the side diverted from the surface of the workpiece in which foil bridges are formed to form projectiles, further comprising two electrodes and adjacent to the metal foil located on the polymer strip, wherein bridges are formed between the contact surface areas of the metal foil, and the electrodes and between which the plasma is formed, are mounted in a support body, through which flat conductors and are connected to a switch for switching large currents and high voltages with a high-voltage source. The polymer strip with the metal foil tightly abuts the support body with the electrodes and the electrodes and protrude above the upper surface of the support body to provide electric contact with the contact surface areas of the applied metal foil. The method of strengthening the surface of workpieces by means of the device according to the invention consists in that one cycle of strengthening the surface of workpieces involves the action of an electric current pulse supplied from a high voltage source after closing the switch by conductors to electrodes between which a high voltage is applied, thereby shorting the circuit on the metal foil at the location of the bridges to form a plasma expanding and by a compressive force acting on the polymer strip part of which hits as a projectile the surface of the workpiece. The plasma is generated by the electric current pulse, in addition to the expansion pressure, is also accelerated by the electromagnetic Lorentz force caused by the passage of electric current, through this plasma in the generated magnetic field.

The invention relates to a method and a device for strengthening the surface of workpieces, in particular of metal ones, by mechanical effects accompanying the impact of small projectiles or by mechanical effects accompanied by the impact of a shockwave induced by plasma created by electric evaporation of a metal foil. The device comprises a polymer strip with a metal foil on the surface of the side diverted from the surface of the workpiece in which foil bridges are formed to form projectiles, further comprising two electrodes and adjacent to the metal foil located on the polymer strip, wherein bridges are formed between the contact surface areas of the metal foil, and the electrodes and between which the plasma is formed, are mounted in a support body, through which flat conductors and are connected to a switch for switching large currents and high voltages with a high-voltage source. The polymer strip with the metal foil tightly abuts the support body with the electrodes and the electrodes and protrude above the upper surface of the support body to provide electric contact with the contact surface areas of the applied metal foil. The method of strengthening the surface of workpieces by means of the device according to the invention consists in that one cycle of strengthening the surface of workpieces involves the action of an electric current pulse supplied from a high voltage source after closing the switch by conductors to electrodes between which a high voltage is applied, thereby shorting the circuit on the metal foil at the location of the bridges to form a plasma expanding and by a compressive force acting on the polymer strip part of which hits as a projectile the surface of the workpiece. The plasma is generated by the electric current pulse, in addition to the expansion pressure, is also accelerated by the electromagnetic Lorentz force caused by the passage of electric current, through this plasma in the generated magnetic field.

A peening device for treating a component includes a shot media propulsion source configured to propel a quantity of shot media. The device also includes a plurality of treatment enclosures each selectively coupleable to the shot media propulsion source. Each of the treatment enclosures has a shape complementary to a corresponding one of a plurality of portions of the component, such that each treatment enclosure and the corresponding portion cooperate to enclose the shot media.

A peening device for treating a component includes a shot media propulsion source configured to propel a quantity of shot media. The device also includes a plurality of treatment enclosures each selectively coupleable to the shot media propulsion source. Each of the treatment enclosures has a shape complementary to a corresponding one of a plurality of portions of the component, such that each treatment enclosure and the corresponding portion cooperate to enclose the shot media.

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.

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.

A method of preparing an engine valve is provided. The method includes hot forging a heat resistant steel at 1,150 to 1,250° C. to mold a valve, aging the molded valve and hollowed-out processing the aging valve. Additionally, the method includes nitride-heating the hollow valve and grinding a surface of a neck of the nitride-heated valve to remove a nitride layer.

A method of preparing an engine valve is provided. The method includes hot forging a heat resistant steel at 1,150 to 1,250° C. to mold a valve, aging the molded valve and hollowed-out processing the aging valve. Additionally, the method includes nitride-heating the hollow valve and grinding a surface of a neck of the nitride-heated valve to remove a nitride layer.