Advanced Ceramic / Metal Polymer Multilayered Coatings for Industrial Applications

Abstract

For the reduction or complete compensation of grease and lubricants in mechanical engineering, special combined coatings for machine components with extended tribological and chemical properties have been developed. Ceramic or metal polymer coating systems are a combination of thermally sprayed hard materials with polymers containing solid lubricants of inorganic and fluorpolymeric origin (i.e. lubricant lacquers). The thermally sprayed hard material guarantees hardness and wear resistance and the lubricant lacquer causes low friction coefficients and smooth gliding performance. In this paper, results of different polymer and multicoating systems on steel substrates are presented. Molybdenum, a cermet based on tungsten carbide, a copper based alloy and chromia were used as wear resistant materials and deposited by means of High Velocity Flame Spraying (HVOF/HVLF). On these surfaces, lubricant lacquers of some μm thickness were deposited by air spraying. The life-time and the friction coefficient of the resulting layers depending on surface texture of the hard material or substrate and lacquer composition were determined using a twin disc tester under dry sliding conditions.