A manufacturing method of a grain-oriented electrical steel sheet according to an embodiment of the present invention includes: manufacturing a cold-rolled sheet; forming a groove in the cold-rolled sheet; removing an Fe—O oxide formed on a surface of the cold-rolled sheet; primary recrystallization annealing the cold-rolled sheet; and applying an annealing separating agent to the primary recrystallized cold-rolled sheet, and secondary recrystallization annealing it, wherein a close contacting property coefficient calculated by Formula 1 below is 0.016 to 1.13.

close contacting property coefficient (S.sub.ad)=(0.8×R)/H.sub.hill-up  [Formula 1] (In Formula 1, R represents the average roughness (μm) of the surface of the cold-rolled sheet after the removing of the oxide, and H.sub.hill-up represents the average height (μm) of the hill-up present on the surface of the cold-rolled sheet after the removing of the oxide.)

A manufacturing method of a grain-oriented electrical steel sheet according to an embodiment of the present invention, includes: manufacturing a cold-rolled sheet; forming a groove by irradiating a laser beam on the cold-rolled sheet; and partially removing an oxide layer formed on a surface of the cold-rolled sheet so that a thickness of the oxide layer remains at 1 to 5 nm, wherein the grain-oriented electrical steel sheet has islands of 0.25 or less having sphericity of 0.5 to 0.9 under the oxide layer under the groove.

The present invention relates to a device as well as a method for the additive manufacture of components by deposition of material layers by layer-by-layer joining of powder particles to one another and/or to an already produced pre-product or substrate, via selective interaction of the powder particles with a high-energy beam, wherein, for smoothing a surface of the component being produced running crosswise to the deposited material layers in between the deposition of two layers of the component, the complete edge region of the last layer that is applied and that runs along a surface of the component being produced is compacted in a direction of action that has a directional component parallel to the build-up direction of the layers, and/or at least one edge region (19) of a surface of the component (3′) is also compacted.

Disclosed is a surface modification technique for permanent magnetic materials. First, a sintered Nd—Fe—B magnet is immersed in a chlorine-containing solution to corrode its surface after the sintered Nd—Fe—B magnet is ground, polished and cleaned, so that atomic vacancies or gaps are produced at the grain boundaries in the surface layer of the corroded sintered Nd—Fe—B magnet; then, compound nanopowders coated on the surface of the sintered Nd—Fe—B magnet are implanted into the grain boundaries by laser shock peening to obtain a gradient nanostructure layer along the depth direction; at the same time, the surface nanocrystallization of the sintered Nd—Fe—B magnet and a residual compressive stress layer are induced by laser shock peening which remarkably improves the corrosion resistance of the sintered Nd—Fe—B magnet.

A laser shock peening apparatus for the surface of a workpiece, said apparatus comprising a resonant cavity. When said apparatus is used to conduct laser shock peening, because of the presence of the resonant cavity, shock waves that would typically escape outward may instead be utilized, and composite shock waves may be formed as a result of the wave reflection and convergence effects of the resonant cavity. Said waves can then be used on the surface of a workpiece twice or multiple times, thereby greatly increasing energy utilization rates. In addition, a fluid-based confinement layer is limited to the inside of the resonant cavity and has a fixed shape, thereby effectively solving the problems of the poor stability of a fluid-based confinement layer and the difficulty with controlling the thickness of such a confinement layer.

The present invention relates to the technical field of material surface peening, and more particularly to an energy compensated equipower density oblique laser shock method. The method includes: acquiring a radius of curvature of a peening region of a part to be processed, and judging a range of a laser incident angle; determining laser parameters, such as laser pulse width, a spot diameter, and required laser energy under a vertical incidence condition; calculating the required laser energy at the minimum incident angle, and judging whether the energy falls within the technical indexes of a laser; and performing laser shock peening on the part by pulse laser beams with different energies. According to the present invention, the laser power or energy is compensated according to changes in the incident angle and the radius of curvature of the part to be processed.

A laser shock and supersonic vibration extrusion co-strengthening device and method. The device comprises a laser assembly, a vibration assembly, a hydraulic assembly and a connecting assembly. The method strengthens a hole (7) formed in a metal sheet (5) simultaneously by laser shock strengthening and supersonic vibration extrusion strengthening; a mandrel (1) is in clearance fit with the hole to constrain the hole, so as to avoid distortion of the hole and a hole angle when the laser shock is performed on an outer surface of a workpiece and to improve the strengthening effect of a hole wall; when the laser shock is performed on the outer surface of the metal sheet, supersonic vibration is applied by the mandrel in the hole; and a three-dimensional pressure stress distribution nearby the hole wall at a certain depth is formed under an interaction produced by power ultrasound and laser shock waves having a certain frequency, amplitude and modality, so that an inner surface having higher anti-fatigue performance and being smoother is provided to the hole. Defects of a traditional strengthening process are overcome, and the problem in strengthening the hole separately through the laser shock or supersonic vibration extrusion is solved.

A method for imparting a predetermined surface contour to a part is provided, the method comprising: identifying a compressive residual stress profile for providing the part with the predetermined surface contour; and laser peening a surface of the part in a treatment mode predetermined with reference to the identified compressive residual stress profile, thereby inducing plastic deformation in the part and thereby imparting a predetermined surface contour to the part that is a different surface contour than the part had prior to the laser peening.

Disclosed is a surface modification technique for permanent magnetic materials. First, a sintered Nd—Fe—B magnet is immersed in a chlorine-containing solution to corrode its surface after the sintered Nd—Fe—B magnet is ground, polished and cleaned, so that atomic vacancies or gaps are produced at the grain boundaries in the surface layer of the corroded sintered Nd—Fe—B magnet; then, compound nanopowders coated on the surface of the sintered Nd—Fe—B magnet are implanted into the grain boundaries by laser shock peening to obtain a gradient nanostructure layer along the depth direction; at the same time, the surface nanocrystallization of the sintered Nd—Fe—B magnet and a residual compressive stress layer are induced by laser shock peening which remarkably improves the corrosion resistance of the sintered Nd—Fe—B magnet.

A laser processing device according an embodiment is a laser processing device that irradiates a processing region of a workpiece with pulsed laser light through a liquid to subject the processing region to a laser peening process or a laser forming process. The laser processing device includes: a laser irradiation unit including a laser oscillator that outputs the pulsed laser light; and an accommodation unit that includes an injection port through which the liquid is injected to the processing region, and accommodates the laser irradiation unit. A pulse width of the pulsed laser light is 200 ps to 2 ns, and the pulsed laser light output from the laser oscillator is emitted to the processing region through a liquid that is injected from the injection port.