HIGH DUCTILITY CAST ALUMINUM BERYLLIUM ALLOYS

摘要

Cast aluminum beryllium alloys have recently been introduced in the market for high performance aerospace applications where high stiffness and low density are critical properties. During solidification of cast aluminum beryllium alloys, a two phase composite microstructure develops in which the primary beryllium phase forms within an aluminum matrix. These alloys typically contain more than 60 weight percent beryllium and are approximately 20% lighter and 3 times stiffer than conventional aluminum alloys. However, these high beryllium alloys are limited by low ductility and the high cost of beryllium. New alloys with lower beryllium content have now been developed, which optimize mechanical properties such as strength and ductility while still providing high specific stiffness. This paper will describe how alloy composition can be tailored to provide different combinations of properties based on application requirements. Results will be discussed in the context of property development in metal matrix composites.