Morphology and properties of non-ferrous alloys in the zones of laser thermal deformation processing

It was established that laser processing of aluminum alloys is possible only with surface fusing. The obtained zone has a homogeneous dispersed structure; dendrites have a size of 2–9 nm. It was shown that the increase in the hardness of aluminum alloys during laser fusing is due to the structure dispersion, increase in the defect density in the crystal structure, and the possible liquation of alloying element atoms having strengthening effect. Structural transformations in the laser-treated zones in copper and nickel alloys are considered, taking into account the local plastic deformation that occurs due to dynamic and thermal shear stresses in the irradiated alloys. The main parameters of the local deformation process are determined by calculation. It was established that the shear stresses in the laser-treated zone are 200–250 MPa. It is shown that the level of emerging stresses is sufficient for plastic deformation and, as a consequence, for dynamic polygonization and recrystallization of the metal in the laser-treated zones. It was established that the residual deformation reaches values of 6–9%. By using the copper alloy L62 as an example, the degree of influence of local plastic deformation on structure formation and the properties of the metal surface layers was shown. This is expressed in dynamic polygonization and recrystallization of local irradiated zones in the non-ferrous alloy. This contributes to the structure formation with a grain size of 4.5–5.0 µm, with an initial grain size of 25 µm.