Nanostructure stabilization in electrodeposited Al–Mg dendrites

Abstract

Electrodeposited Al−Mg dendrites with globular morphology exhibited core−shell (coarse−fine) type microstructure with grain sizes ~100 and ~16 nm, respectively. The grain boundary and grain compositions of core are ~10 and ~6 at.% Mg, respectively. Those of shell are ~36 and ~20 at.% Mg, respectively. The excess Mg ratio at boundaries of shell and core (Mg,fine/Mg,coarse) is 1.17:1. This relative grain boundaries segregation of Mg decreases the grain boundary energy from coarse to fine region and can result in nanostructure stabilization of fine shell at ~16 nm.

Thermodynamic Stability of Nano-grained Alloys Against Grain Coarsening and Precipitation of Macroscopic Phases

“…[20][21][22][23][24][25][26][27][28] That is why the purpose of this paper is to develop a model for thermodynamic stability of such NG alloys. Although there is plenty of previous literature on both the synthesis [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] and on modeling the stabilization of NG alloys ) (see also reviews [89][90][91][92][93] ), the present paper is novel as it puts this question into a wider framework of the nano-Calphad method, [94,95] i.e., into the thermodynamic framework originally developed by Gibbs. [96] All previous models on GB stability apply the simplest Langmuir-McLean model [97,98] (see also Reference 99) for modeling grain boundary (GB) energy.…”

Effect of alloying elements on magnesium alloy damping capacities at room temperature

“…However, elements such as Al, Zn, Ca, etc. can be used as alloying elements in magnesium alloys, where they are known to enhance the mechanical properties of the resulting alloys [8][9][10][11][12][13][14]. For example, Al can improve the strength and plasticity of the alloy and improve the structure of its oxide film [8][9]; the solid solubility of zinc in magnesium is high and decreases dramatically with decreasing temperature, which can cause solid-solution strengthening and aging strengthening of the alloy [10][11].…”