02-04-2011, 11:04 AM
SYNOPSIS
Coating has always been a necessary job for protection of the object (substrate). Coating is a covering that is applied to the surface of an object, usually referred to as the substrate. In many cases coatings are applied to improve surface properties of the substrate, such as appearance, adhesion, wetability, corrosion resistance, wear resistance, and scratch resistance.
This project is directed to a system for making the use of metal powder for the purpose of making coating on substrate for purpose of improving its properties. This project deals with the deposition of metallic powder coatings using the kinetic spray process (also referred to as cold spray or cold gas dynamic spray). This coating process is a relatively new process. In the coating process, metallic particles (~50–150 Am) are injected into a De-Laval nozzle and propelled.
A De-Laval nozzle (convergent-divergent type) is used for spraying of the metal powder on the substrate which is done with the help of compressed pre-heated gas coming out from compressor and heater which passes through the nozzle and hits the substrate. Due to this hitting action, metal powder makes plastic deformation on the substrate and thus permanent coating is achieved.
Thus wear and corrosion test is done on the prepared specimens (magnesium and mild steel plates) and compared with other samples to show the enhanced corrosion and wear resistance property of the substrate which is formed by cold spray dynamic coating.