Grain refinement in laser remelted Mg-3Nd-1Gd-0.5Zr alloy. (1st July 2020)

• Record Type: Journal Article
• Authors: Zhang, Duyao; Qiu, Dong; Zhu, Suming; Dargusch, Matthew; StJohn, David; Easton, Mark
• Is Part Of: Scripta materialia. Number 183(2020)
• Page Start: 12
• Page End: 16
• Publication Date: 2020-07-01
• Subjects: Magnesium alloys -- Rapid solidification -- Solidification microstructure -- Grain refining -- Laser treatment; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2020.03.006
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Columnar grains are normally favoured with the high cooling rate and steep thermal gradient in laser-based additive manufacturing. Here, we demonstrate that fine, fully equiaxed grains can be achieved in Mg-3Nd-1Gd-0.5Zr (EV31) alloy by laser surface remelting. The grains in the melt pool are remarkably refined from 74 µm to 3.5 µm, which can be attributed to the growth restriction effect, i.e. the constitutional supercooling formed by Zr solute during solidification in combination with the high cooling rate imposed by laser surface remelting. This novel finding could be applied for the control of grain morphology and alloy design for additive manufacturing applications. Graphical abstract: Image, graphical abstract