Effect of Laser Surface Melting on Atmospheric Plasma Sprayed High-Entropy Alloy Coatings

Laser surface melting (LSM) is the most helpful technique to improve the surface properties of the high-entropy alloy (HEA). LSM reduces the pores, voids, cracks, and other surface defects at the sample's surface. LSM utilized high-power fiber laser to partially or fully melt the surface to enhance the various properties such as wear, corrosion, and fatigue resistance without impacting the bulk material properties. LSM of HEA enhances the microhardness and wear properties by reducing the pores and surface defects. It facilitates flexibility such as control over laser spot diameter, penetration depth, mode of operation, and higher cooling rate, which increase its applicability in various applications such as automobile, medical, and aerospace. The relevance of LSM in wear-resistant applications is increasing among multiple sectors. The application domain of LSM ranges from cladding to repairing components. The LSM gained popularity over time due to its ability to improve the surface properties of specimens in a lower lead time. The HEA is a novel class of material used for wear and high-temperature applications due to its high configurational entropy and superior wear, oxidation, and corrosion resistance. Many researchers are working on the LSM of various HEAs to be applied in wear resistance applications. This chapter introduces the different types of laser-based surface modification techniques and their application in detail. This chapter also describes the effect of LSM on the microstructure and microhardness of atmospheric plasma sprayed HEA and compares it with the as-deposited alloy. This chapter will serve as a quick start for researchers to appreciate the improvement with laser-based surface modification techniques.