Thermal spray applications in powertrain contribute to the saving of energy and material resources

Thermal spray technology has found its way into the automotive industry and is widely used for an expanding range of applications. A variety of thermal spray processes are available for coating applications on parts of the piston group, the clutch, the gearbox and the valve train. han six years ago a leading European manufacturer of passenger cars has put a thermal spray process into series production, to coat cylinder bore surfaces of aluminium engine blocks from high power diesel engines. The coating, with its particular surface topography, decreases the friction of the piston group significantly, leading to a reduction of fuel consumption of 2–4%. In addition to fuel savings the oil consumption can be reduced by a factor of 2–3 and therefore help to achieve lower emission values. Based on this cylinder bore coating technology Sulzer Metco has developed a range of materials to provide optimum solutions for the different types of engines with their specific requirements. These materials cover the needs for high corrosion resistance in marine engines or engines run on biofuels, abrasion resistance in heavy duty truck engines or very low friction in racing engines. This paper will focus on plasma spray coating of cylinder liners for heavy duty diesel (HDD) truck engines and highlight the technical feasibility for the measure of cost reduction in series production.