METHOD FOR OBTAINING NANOSTRUCTURED METAL BILLET BY LASER TREATMENT Russian patent published in 2021 - IPC B82B3/00 B23K26/354 B23K26/12 B23K20/24 

FIELD: metallurgy.

SUBSTANCE: invention relates to a method for obtaining a nanostructured surface of a metal billet by laser treatment before diffusion welding of metal workpieces. The method involves placing the processed metal billet in a sealed chamber filled with an inert gas to a pressure of 151-203 kPa, acting on the processed surface to form molten metal with a laser beam moving along the processed surface with a laser spot power density on the surface of the part, providing the formation of near-surface plasma in the vapors of the molten metal. Nanostructuring of the treated surface is carried out by a laser beam of a nanosecond pulsed laser with an energy power density in the range from 1.0 to 5 J/cm² before the formation of relief structures on the nanostructured surface in the form of riblets, micropores, curved channels, microconuses with transverse dimensions from 1 to 5 microns, as well as spherical structures with a diameter of about 500 nm on cylindrical stands-legs with a width of about 300 nm. The number of laser pulses per unit irradiation spot is determined by the formula N=D²⋅ν/(u⋅b), where N is the number of laser pulses per unit irradiation spot, D is the diameter of the irradiation spot, ν is the frequency of laser pulses, u is the speed of scanning the laser beam over the surface of the workpiece to be processed, b is the vertical movement step of the laser beam. After nanostructuring, diffusion welding of metal workpieces on the nanostructured surface is carried out in the second sealed chamber by pressure and heating of the welded metal workpieces in an atmosphere of inert gases. Dissimilar metals or their alloys are used as the material of the welded metal blanks.

EFFECT: increased quality of the connection of dissimilar metal workpieces during diffusion welding.

11 cl, 4 dwg, 1 ex, 1 tbl