Shear-assisted processing and extrusion (ShAPE) is used to consolidate Al-4.2Mg-1.6Zr-0.25Si-0.1Fe (wt.%) powders. The extruded alloy exhibits: (i) near-zero porosity; (ii) an attractive combination of tensile yield strength (~220 MPa), ultimate strength (330 MPa) and elongation (>20%); and (iii) excellent thermal stability at 400 ºC. The ultra-fine grain size in the gas-atomized powders – created and stabilized by primary L12-Al3Zr submicron precipitates - is maintained after consolidation and subsequent exposure at 400 ºC, contributing twice as much to strength as Mg in solid-solution. Electron microscopy reveals the microstructure of the L12-Al3Zr precipitates, and other precipitates (Mg2Si and Al3Fe) and dispersoids (oxides).
Revised: July 21, 2020 |
Published: September 1, 2020
Citation
Croteau J.R., J. Jung, S.A. Whalen, J.T. Darsell, A. Mello, D. Holstine, and K. Lay, et al. 2020.Ultrafine-grained Al-Mg-Zr Alloy Processed by Shear-Assisted Extrusion with High Thermal Stability.Scripta Materialia 186.PNNL-SA-151920.doi:10.1016/j.scriptamat.2020.05.051