Advances in Surface Engineering

*Engineering Steels and High Entropy-Alloys*

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**239**

**Chapter 13**

**Abstract**

with substrates have been developed.

**1. Introduction**

Laser Surface Treatment

*Anas Ahmad Siddiqui and Avanish Kumar Dubey*

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

**Keywords:** laser surface modification, laser surface alloying, laser cladding

development of materials and surface properties has become essential.

Most of the advanced applications require superior surface properties such as high hardness, strength, wear resistance, corrosion resistance, high temperature oxidation resistance, and improved magnetic and chemical behavior. All these properties can be incorporated and developed by modifying the surface of the

Metals and their alloys are one of the means to fulfill our imagination. With change in necessity, their utility is also changing. Today industries require materials that can meet the demands of challenging markets. In this age of miniaturization, we require materials that can form the framework for new technologies. Advanced biomaterials for bones and dentures with critical surface properties have been developed [1, 2]. These materials have shown to perform better than the available materials. Artificial bones of Mg and their alloys have been researched [3]. These may restrict the requirement of recursive surgeries in case of implants. In the nuclear industry, materials which can restrict the harmful radiations while themselves remaining neutral have been proposed [4]. Such materials may be able to improve the working conditions of nuclear industry workers and may restrict the radiation leakages in prolonged use. Chromium has been used for decades as a surface hardening and corrosion-resisting agent. In recent years there are some articles that discuss the effect of chromium on health [5, 6]. It has been found that few states of chromium may be the probable cause of cancer. Hence, alternate materials possessing properties similar to chromium coatings have been reported [7]. In an attempt to improve the efficiency of power plants, turbine blades which can handle high stresses have been tested [8]. These materials may help boost the limits of power plants, aircrafts, and other propulsion systems. The thrust of ever-expanding horizons of knowledge
