真空碳热还原制备Mg-Li合金热力学分析  

Thermodynamic Analysis of Mg-Li Alloys Preparation by a Vacuum Carbothermic Reduction Method

作　　者：张玺[1] 张南夷 张劲松 黄鹏[1] 彭晓东[1,3] 谢卫东[1,3] 

机构地区：[1]重庆大学,重庆400045 [2]重庆长安汽车股份有限公司,重庆400060 [3]国家镁合金材料工程技术研究中心,重庆400044

出　　处：《稀有金属材料与工程》2016年第1期127-131,共5页Rare Metal Materials and Engineering

基　　金：科技部国际科技合作计划(2010DFR50010)

摘　　要：提出了真空碳热还原制备Mg-Li合金的新思路,并对还原反应进行了热力学分析,研究了还原反应的反应式、吉布斯自由能及临界还原温度。结果表明:真空碳热还原制备Mg-Li合金具备热力学可行性,且其吉布斯自由能随真空度和反应温度的升高而降低;相同真空度下,该反应的临界反应温度低于真空碳热还原制备金属Mg、金属Li的临界温度,反应更容易进行;当真空度为10 Pa,Li_2O的相对比例为0.1时,真空碳热还原制备Mg-Li合金的临界反应温度为1345 K;在常规皮江法(真空硅热还原法)制镁的反应条件下,不论反应物料中Mg O、Li_2O相对比例为多少,真空碳热还原制备Mg-Li合金均具有热力学可行性。A new preparation method of Mg-Li alloys by vacuum carbothermic reduction was proposed. The thermodynamics of the reduction reactions were analyzed and the equations of the reduction reactions, the Gibbs free energy and critical temperature of reactions have also been studied. The results show that vacuum carbothermic reduction producing Mg-Li alloys is thermodynamically feasible. Under the condition of other factors unchanged, with the increase of vacuum degree and reaction temperature, the Gibbs free energy of reduction reaction declines. Under the same vacuum degree condition, the critical temperature of the vacuum carbothermic reduction producing Mg-Li alloys is lower than that of producing metallic Mg or metallic Li, and the reaction is easier. When the vacuum degree is 10 Pa and the relative proportion of Li2 O is 0.1, the critical temperature of the vacuum carbothermic reduction producing Mg-Li alloys is 1345 K. Under the reaction temperature（about 1473 K） and vacuum degree（about 13.3 Pa） of conventional Pidgeon process（producing metallic magnesium by vacuum silicothermic reduction） conditions, no matter what the relative proportions of magnesium oxide and lithium oxide in the hybrid system, the vacuum carbothermic reduction producing Mg-Li alloys is thermodynamically feasible.

关 键 词：MG-LI合金 真空碳还原 热力学分析 

分 类 号：TG146.22[一般工业技术—材料科学与工程]