LASER Cladding—A Post Processing Technique for Coating, Repair and Re-manufacturing

Abstract

LASER cladding technology has a strong applicability in the surface coating sector, mainly in metallic surfaces, although, it has been arousing, more and more, the interest in the components repair and rapid prototyping sector. The reason for its creation was to improve the quality of component surfaces, overcoming the already known disadvantages in traditional processes as TIG—Tungsten Inert Gas welding also known as GTAW—Gas Tungsten Arc Welding, plasma spray or HVOF—High Velocity Oxy Fuel, being these disadvantages the high dilution of the substrate material into the coating/cladding, the large increase of temperature imposed by the process resulting in distortions in the parts, the low precision in material deposition, porosities, micro-cracks, bond defects and problems in the adherence to the substrate. The application of LASER technology for material addition/deposition processes come, for example, to improve the precision of the material deposition, to reduce the dilution of the substrate and the temperature increase of the component to be coated and also, the utilization of a LASER beam, does not cause unfavourable alterations in the mechanical properties of the melt pool. LASER cladding technology can be considered interdisciplinary, in so far as it includes various technological areas, namely the LASER technology, drawing area and computer assisted production, the robotic and control area and also the area of powder metallurgy. The majority of the scientific publications about LASER cladded coatings refer mainly its use in materials from aerospace, medical and automotive industries. Therefore, this chapter will attempt to focus on the LASER Cladding growing applications of this recent technology and advantages and limitations of this process. This chapter will begin with a historic description of the LASER Cladding technology, followed by the principles of the process operation, the applicability of the process, the state of art of materials utilized in the Cladding process, and the advantages and limitations of the process. At the end of the chapter will be present the recent developments in LASER Cladding process.