ABSTRACT
Among the conventionally used additive manufacturing surface repair and modification thermal techniques, such as thermal spraying, plasma nitriding, arc welding, laser shot peening, laser surface melting, and hardening, laser cladding is the most efficient and extensively used process for high-value components in military, aerospace, automobile parts, and biomedical applications to improve fatigue life, biocompatibility, and wear and corrosion resistance. Laser cladding is the deposition of a hard and wear-resistant protective layer over a substrate using high-power laser beam as heat source in alloys. It is in fact a kind of directed energy deposition technology, specifically used for repair, modification, remanufacturing, and design of new tools. With the advent of modern integrated tooling of forming manufacturing, die molding is a rising technology toward high machine accuracy in finishing and manufacturing of tools. For a single coating, the layer thickness is usually up to 2 mm, and current laser models are presented with compact size wobble head and can quickly switch between beam shapes and processes. Coating layers produced by laser cladding combined with machining in hybrid processes shows minimal dilution and good metallurgical bond, and the process is of crucial importance as it prolongs the life span of alloys by addressing low hardness and poor wear characteristics. In laser cladding, the powder injection method is useful over pre-placed powder and wire feeding methods. This chapter discusses the various parameters of laser cladding, such as laser power, laser beam velocity, beam radius, powder feed rate, and clad dimensions, and their effect on the microstructure, microhardness, cracking, phase formation, and mechanical and triboelectric properties of coating materials.
