Mg-Zn-RE(Ce,Nd)系镁合金强化相析出过程与强化机制的研究

项目名称： Mg-Zn-RE(Ce,Nd)系镁合金强化相析出过程与强化机制的研究

项目编号： No.51301032

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 黄明丽

作者单位： 东北大学

项目金额： 25万元

中文摘要： Mg-Zn-Ce与Mg-Zn-Nd镁合金系具有丰富的强化相，Ce与Nd能够有效提高合金塑变形能力，是非常具有应用潜力的合金系。本项目拟以相平衡及其析出转变为基础，以合金元素固溶度特征为依据，明确这两种镁合金系强化相的析出过程及强化机理。本项目将研究这两个镁合金系的凝固过程及凝固相，确定凝固过程出现的合金相的晶体结构特征（晶格参数、空间群及晶胞原子占位）；利用热力学计算与第一原理计算的方法研究平衡相、凝固相的热力学参数与力学性质参数，确定具有较好强化效果的合金相；研究Mg-Zn-RE（Ce, Nd）系镁合金析出转变动力学与成分的关系；研究这两种合金系合金的时效析出过程，明确时效析出相的形成特征；研究第二相种类（初生相、沉淀相）、状态（共格－半共格－非共格）、形貌（球状、杆状等）与分布（晶粒内部、晶界）对合金强韧性能的影响机制。从而为高性能稀土镁合金的合金设计及热处理等工艺的制定提供可靠依据。

中文关键词： Mg-Zn-RE合金；析出相；力学性能；时效处理；热轧

英文摘要： Mg-Zn-Ce system and Mg-Zn-Nd system have abundant strengthening phases, and the toughening of the alloys can be improved by the addition of Ce and Nd. So, the application potential of the alloys of the two systems are promising. The project will identify the precipitation process and strengthening mechanisms of strenghening phases in the two ternary magnesium alloy systems. The solidification process and the solidifying phases of the Mg-Zn-Ce system and Mg-Zn-Nd system in the Mg-rich corner will be studied, and the crystal structure of the phases (lattice parameters, space group and atom sites in crystal lattice) should be identified. In order to accertain the reasonable strengthening phases, the project will study the thermodynamic data and mechanical property data of the intermetallic phases by using methods of thermodynamic calculation and first-principles calculation. Further more, the relationships between the precipitation kinetics and the components of Mg-Zn-RE(Ce, Nd) alloys will be studied . This project will investigate the ageing process of the two ternary systems' alloys, and identify the character of the precipitation phases during the ageing process. Then,the impact of types (primary phases, precipitates), the stage(coherence-semi coherence-incoherence), the morphology (disc shaped, rod shaped et a

英文关键词： Mg-Zn-RE alloy；Precipitation phase；Mechanical properties；Aging treatment；Hot rolling