Characterization of precipitation in 2000 series aluminium alloys using neutron diffraction, sans and sem methods

Abstract

Combination of high-resolution time-of-flight (TOF) neutron diffraction, scanning electron microscopy (SEM) and small angle neutron scattering (SANS) have been used to study hardening precipitation in 2014Al and 2124Al alloys. Neutron diffraction experiment revealed presence of tetragonal CuAl2 phase (θ/θ¿ precipitates) in 2014Al alloy and orthorhombic CuMgAl2 phase (S-precipitates) in 2124Al alloy. SEM image analysis revealed that the θ/θ¿-precipitates have platelet morphology while the S-precipitates exhibit rod-like shapes. From SANS data analysis the characteristic dimensions of precipitate particles and their polydisperse distributions were estimated.