How to pretreat non-metallic surfaces?

       When non-metallic materials such as ceramics, glass, plastic, and wood need to be thermally sprayed, the surface pretreatment method is different from that of ordinary metal materials. For non-metallic materials such as ceramics, since the thermophysical properties such as melting point, expansion coefficient, thermal conductivity, etc. are different from ordinary metals, and they are resistant to oxidation, they can generally be uniformly heated to a red-hot state, that is, using high matrix preheating. hot temperature, and then spray directly (but should prevent the matrix from bursting due to rapid heating or local overheating); for organic materials such as wood and plastic, due to their soft, flammable, low softening temperature, etc., generally mild sandblasting pretreatment , and then spray a layer of low melting point metal such as tin, zinc as the base coat, and then spray the top coat.