Ultrafine-grained Al-Mg-Zr alloy processed by shear-assisted extrusion with high thermal stability. (September 2020)

• Record Type: Journal Article
• Authors: Croteau, Joseph R.; Jung, Jae-Gil; Whalen, Scott A.; Darsell, Jens; Mello, Austin; Holstine, Dallas; Lay, Kylee; Hansen, Michael; Dunand, David C.; Vo, Nhon Q.
• Is Part Of: Scripta materialia. Number 186(2020)
• Page Start: 326
• Page End: 330
• Publication Date: 2020-09
• Subjects: Friction extrusion -- High-strength aluminum powder -- Ultra-fine grain -- Thermal stability; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2020.05.051
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: 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 °C. The ultra-fine grain size in the gas-atomized powders – created and stabilized by primary L12 -Al3 Zr submicron precipitates - is maintained after consolidation and subsequent exposure at 400 °C, contributing twice as much to strength as Mg in solid-solution. Electron microscopy reveals the microstructure of the L12 -Al3 Zr precipitates, and other precipitates (Mg2 Si and Al3 Fe) and dispersoids (oxides). Graphical abstract: Image, graphical abstract