Processing of Aluminum alloy 2090 for superplasticity

Abstract

Existing superplastic forming techniques for Al alloys rely on deformation at temperatures of 500°C to achieve the desired ductilities . The Al alloy 2090 (Al-Li-Cu- Zr) has been successfully fabricated by such techniques, but at temperatures where cavitation during forming may significantly reduce the mechanical properties of the final product. It has been previously shown that cavitation can be effectively suppressed by forming at lower temperatures. The purpose of this research is to investigate the applicability of thermomechanical processing methods (developed at NPS for Al­ Mg-X alloys) to produce a refined microstructure capable of supporting superplasticity at lower temperatures in Al 2090.