Elevated temperature tensile behaviour of 5183 aluminium alloy made by electrospark deposition additive manufacturing

This study focuses on the microstructure and tensile behaviour of the as-deposited 5183 Al–Mg alloy fabricated by electrospark deposition (ESD) additive manufacturing. Tensile tests were carried out at temperatures from 293K to 773K with strain rates from 1 × 10⁻⁴/s to 1 × 10⁻¹/s, and the microstructure of the specimens was characterised by XRD, SEM, EBSD and TEM. The results showed that the initial microstructure consists of equiaxed grains of about 60 μm diameter with no oriented texture. As the deformation temperature increased from 293K to 773K, the alloy's UTS dropped from 292 MPa to 57 MPa, and elongation rose from 37% to 61%. The strain rate sensitivity was relatively low (less than 0.034) in the intermediate temperature region (293K–473K) and stepped up to 0.111 ± 0.003 when the experimental condition turned to elevated temperatures (573K–773K). The microstructure of specimens deformed at intermediate temperatures (293K–473K) revealed typical dislocation entanglement and dynamic recovery characteristics. Recrystallisation occurred at higher temperatures (573K–773K), and texture intensity fell to a minimum level. The deformation of the as-deposited 5183 aluminium alloy at elevated temperatures is a diffusion mechanism controlled by thermal activation, and the thermal activation energy is about 162 kJ/mol.