Abstract

Laser processing is often used in many technological processes for welding, cutting, marking, etc. However, it has been gaining popularity for several years as a surface modification process, including cleaning, polishing, surfacing, and hardening. These methods are used to modify the physicochemical properties to enhance hardness, wear resistance, corrosion resistance, and the propagation of microcracks on the metal surface. It has been found that the effectiveness of laser radiation (short pulses of laser light) depends on the thermal properties of the alloy being treated and the process parameters. Also significant is optical absorption, which determines the coupling of laser radiation energy to the workpiece during the melting of its surface. The study, considered preliminary, was conducted on flat sparrows of AlSi11 alloy under argon shielding. It was possible to fragment the microstructure components of the studied alloy at depths of several micrometers, depending on the laser power density, spot size, and travel speed. The fragmented α(Al) dendrites in the melted laser zone are oriented toward the temperature gradient. At the very surface, they gradually lose their secondary arms, assuming the morphology of compact cells. This method can harden large or local areas that are inaccessible to other surface treatment methods, such as piston ring gaps in internal combustion engines, specifically the part of the piston shell that operates under extreme thermo-mechanical and tribological stresses.