Thermal Spray is a directed spray process, in which material, generally in molten form, is accelerated to high velocities, impinging upon a substrate, where a dense and strongly adhered deposit is rapidly built. In the case of ceramic deposits, it is necessary to bring the particles to well above the melting point, which is achieved by either a combustion flame or a thermal plasma arc. The deposit microstructure and, thus, properties, aside from being dependent on the spray material, rely on the processing parameters, which are numerous and complex. In recent years, through concerted, integrated efforts of the Center for Thermal Spray Research at the State University of New York at Stony Brook and others, significant fundamental understanding of the process has been achieved, allowing for an enhanced control of the process.