Kinetic spray: a new coating process

Abstract

A relatively new coating process that uses high velocity gas to accelerate powder particles to velocities on the order of 500 m/s is being used to produce low porosity, low oxide, and low residual stress coatings. The powder particles are not melted or thermally softened prior to impact with the substrate. The coating process depends primarily on the conversion of the particle's kinetic energy to thermal energy (heat) and strain energy when the incident powder particles impact the substrate surface at high velocity. The time scale for the particle deformation and subsequent bonding to the substrate is on the order of 100 to 400 nsec. An overview of the kinetic spray process, the history, description of the equipment, as well as a model for the coating formation process will be presented.