Laser Surface Treatment

Abstract

Laser surface treatment (LST) utilizes intense thermal energy of laser beam for modification, alloying, and cladding surface of substrate materials. In LST very high cooling rates of 104-106°C/s can be achieved. Such high cooling rate arrests the possibilities of segregation in the case of multicomponent systems. Moreover, very narrow heat-affected zone (HAZ) and easy automation make it suitable for large-scale industrial production. LST depends on many process parameters such as laser power, scan speed, focal length, spot size, substrate temperature, and type of material. Selection of proper range of process parameters for good surface quality is essential. Pores and cracks may arise due to improper selection of parameters. Multilayered, high-entropy, thermal barrier coatings using LST with good bonding with substrates have been developed.

Determination of Preliminary Operating Intervals of the Power Density for Laser Technological Processes on Copper Samples

“…it is the design maximum density of the power of the laser radiation. The maximum power density qsmax for the laser system is determined by formula (5), which is required for the preliminary operating intervals of the power density of evaporation qscv. Calculations of the critical melting power density for different speeds for the two lasers (fibre laser and CuBr laser) are performed using expressions (1) and ( 2).…”

“…To determine the preliminary operating intervals of the power density, it is necessary to determine the maximum power density of the two lasers. According to formula (5), the following values are obtained: qsmax = 10.1×10 10 W/m 2 for the fibre laser and qsmax = 6.37×10 10 W/m 2 for the CuBr laser. The preliminary operating intervals of the power density for oxidation, melting and vaporization at different rates for fibre laser and CuBr laser, respectively, are given in Tables 1 and 2.…”

“…Laser surface treatment technologies offer a broad spectrum of opportunities to achieve innovative surface properties. The modification of the surface layer is dictated by laser processing parameters and the optical and thermal properties of materials [4] [5].These factors collectively influence the resulting temperature profile within the processing zone, thereby instigating alterations in the material's properties (including mechanical, corrosion resistance, tribological, antibacterial, etc.) in both depth and radial directions [6] [7] [8].…”