New Approaches in the Hypersonic Flame Spray Coating for Cylinder Liners in Aluminum Crankcases

Actual trends with regard to light weight design in the automotive industry, in order to reduce fuel consumption and pollution emissions as well as improve the engine efficiency lead to the increasing use of light weight engine components. Due to the harsh operation conditions, the aluminum cylinder surface must be reinforced, and new techniques have been developed and applied. A very promising technological alternative is the use of HVOF (high velocity oxygen fuel) deposited internal coatings, showing improved coating quality results compared to APS (atmospheric plasma spray) coatings.

Several HVOF (High Velocity Oxygen Fuels) coating processes (with different fuel gases/fluids) were compared and studied, with a complete mechanical characterization and evaluation of the coatings. Also an economical comparison for the different coating systems is shown.