Kinetic modeling of high-temperature oxidation of pure Mg

作     者：Sa Ma Fangzhou Xing Na Ta Lijun Zhang Sa Ma;Fangzhou Xing;Na Ta;Lijun Zhang

作者机构：State Key Laboratory of Powder MetallurgyCentral South UniversityChangshaHunan 410083P.R.China Max-Planck-Institut fiir Eisenforschung GmbHMax-Planck-Straβe 140237DusseldorfGermany 

出 版 物：《Journal of Magnesium and Alloys》 (镁合金学报（英文）)

年 卷 期：2020年第8卷第3期

页      面：819-831页

核心收录：

学科分类：08[工学] 0806[工学-冶金工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：Hunan Provincial Science and Technology Program of China, (2017RS3002) Huxiang Youth Talent Plan Central South University, CSU, (2282019SYLB026) National Key Research and Development Program of China, NKRDPC, (2016YFB0301101) Fundamental Research Funds for Central Universities of the Central South University, (2019zzts485) Huxiang Youth Talent Support Program 

主　　题：MgO Diffusion Oxidation Atomic mobility CALPHAD Wagner's model 

摘      要：A variety of experimental tracer diffusivities of Mg and O in magnesium oxide available in the literature were first assessed.Atomic mobilities including bulk and short-circuit diffusion of Mg and O were then obtained by means of the CALPHAD(Calculation of Phase Diagram)approach.Afterwards,the diffusion-controlled kinetic model of oxidation in a gas-MgO-Mg environment was developed based on the moving boundary model and Fick s law,coupling with the modified thermodynamic description of MgO.A mathematical expression for parabolic rate constant kp of the oxide scale was derived for magnesia and correlated with the thermodynamic and diffusion kinetic information.The evaluated kp results were in line with the experimental data.Finally,the oxidation process of pure magnesium at 673 K was model-predicted,and the predicted evolution of the oxide thicknesses agreed very well with the experimental data.It was indicated that the grain boundaries diffusion of magnesium cations predominated the high temperature oxidation process.