New Aluminum Piston Alloy with Increased Fatigue Strength at High Temperatures

A new piston alloy was developed by combining the chemical compositions of copper and silicon rich aluminum alloys. Copper increases fatigue strength at low and intermediate temperatures of up to 250 °C whereas the increased amount of intermetallics raises fatigue strength at high temperature of 340 °C or beyond.

Casting difficulties can be handled by grain refinement of the α-aluminum. Engine tests show an increase of the lifetime of the thermally and mechanically highly loaded bowl rims of DI-Diesel pistons by a factor of four.