| abstract |
A light weight and high strength aluminum alloy and a process for producing such an alloy, which alloy is suitable for forming automotive engine components, including pistons. In a preferred embodiment, 80 to 99.5% by volume of an aluminum alloy powder or a mixed powder composed of pure metal powders or master alloy powders is blended with 0.5 to 20% by volume of at least one of carbon or graphite powder, an oxide powder, a carbide powder and a nitride powder. The blend is then mechanically alloyed, following which the thereby-obtained powder is subjected to working such as by compaction and hot forging, hot pressing, cold isostatic pressing and hot forging, or cold isostatic pressing and hot extrusion. By the use of mechanical alloying, the advantages of a rapidly solidified powder having a supersaturated solid solution and uniform fine crystal grains are attained, and the effect of dispersion-strengthening is brought about by the addition of dispersion particles to the micro structure of the rapidly solidified powder. |