Mechanical properties and applications of aluminum scandium alloys at elevated temperatures

Abstract

The mechanical properties of a unique, dispersion-strengthened aluminum alloy, which contains scandium (Sc) are described. The alloy, named Pandalloy® Gen2, is produced by vacuum hot pressing atomized powders that are rapidly solidified at cooling rates of 103–105 °C per second. Rapid solidification creates fine, intermetallic particles that are dispersed throughout the aluminum matrix. The particles are composed of combinations of Al, Gd, Ni, Sc, and Zr, which solidify as finely dispersed intermetallic phases that are resistant to coarsening. The thermally stable intermetallic dispersoids impart superior elevated temperature strength at temperatures up to 371 °C (700 °F) compared to conventional heat treated aluminum alloys such as AA2618-T61. Initial application of Pandalloy® Gen2 is focused on race car pistons where advantages of high tensile strength, high cycle fatigue strength, excellent thermal stability and resistance to cracking, can be used to achieve higher combustion cylinder temperatures, greater horsepower and increased durability of pistons.