Mg-Dy-Ho合金的稀土作用机制及基于高通量计算合金组分优化研究

稀土金属作为镁的合金元素，能够细化晶粒，改善加工和力学性能。但生物相容性各异的稀土金属对可降解镁合金性能的作用机制尚不明确。本项目提出选用具有良好生物相容性的镝和钬采用合金化和压力铸造，结合材料特征库的建立，高通量计算，材料试验和预测不同组分稀土镁合金性能的研究思路。探讨在压力铸造过程中，合金元素镝和钬对二元和三元稀土镁合金结晶过程的影响；分析稀土金属镝和钬对镁合金微观结构，力学性能，耐腐蚀性和生物相容性的作用机制；结合热力学知识绘制三元镁镝钬合金的相图；探讨二元和三元稀土镁合金的组分优化方法。主要创新有：一是制备新型稀土镁镝钬合金；二是提出建立镁镝和镁钬合金材料性能特征数据库，为材料计算工程提供理论基础；三是结合材料试验-计算模型优化稀土合金组分，缩短稀土合金试制周期；四是在高通量计算预测合金物相及性能基础上，结合热力学知识绘制镁镝钬合金热力学特征图谱及物相，建立三元相图。

Rare earth metals (REs), as the alloying elements of magnesium, can refine grain size and improve processing and mechanical properties. Duo to their various biocompatibilities and physical chemistry, the effects on the properties of biodegradable Mg-REs is still unclear. This project proposes a novel method that fabricating Mg-REs alloys by pressure casting using the biocompatible alloying elements Dy and Ho with the aims to predict the properties of the Mg-REs alloying tightly coupled with the establishment of the material characteristics database, high-throughput calculation and experiment; Explore the influence on alloying crystallization, and analyze the mechanisms of the REs on the microstructure, mechanical properties, corrosion resistance and biocompatibility of Mg-REs based alloys; Propose the phase diagram of ternary Mg-Dy-Ho alloy; Establish the theoretical basis of composition optimization for Mg-REs alloy. The main innovations are as follows: 1) the preparation of novel biocompatible Mg-Dy-Ho alloys; 2) the establishment of a database of the material characteristics for Mg-REs alloys; 3) to shorten the trial production cycles of the Mg-REs alloys combined with the experiment-computational models, providing theoretical basis for materials composition optimization; 4) to establish the ternary phase diagram of Mg-Dy-Ho alloy coupled with the thermodynamic features of the metals based on the high-throughput calculations and the newly formed intermetallics.