Phenomenology and Application of Low Temperature and High Strain Rate Superplasticity in Aluminium Alloy 1420

摘要

The superplastic behaviour of the commercial alloy 1420 (Al-Mg-Li-Zr) with coarsecrystalline (CC) (grain size, d～50μm) and microcrystalline (MC) (d～5μm) structure was analysed at tension in the temperature range of 320-450°C and strain rates of 10~(-4)-10~0s~(-1). The alloy revealed features of low temperature superplasticity independently of grain size and high strain rate superplasticity in the MC condition. The parameters of superplastic die forging of CC and MC alloy in the above temperature-rate range and mechanical properties of components were compared. The data obtained are discussed in terms of potential application of low temperature and high strain rate superplasticity for processing of components from the alloy billets with initially coarse-, micro- and submicrocrystalline structure.