第一性原理设计和筛选高性能钴基高温合金

项目名称： 第一性原理设计和筛选高性能钴基高温合金

项目编号： No.51301126

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： 张华磊

作者单位： 西安交通大学

项目金额： 25万元

中文摘要： 钴基高温合金是新兴的高性能工程材料，它具有比常规的镍基高温合金更好的抗腐蚀、抗氧化和抗疲劳等性能，实验表明γ/γ'双相硬化机制的发现使其具有比镍合金更高的高温强度和融化温度，有望用于高精尖设备如航空发动机和发电系统等。优化合金组元及其配比是得到高性能材料的关键。实验方法耗资巨大且低效。分子模拟方法和传统的第一性原理方法都不适于筛选合金，前者精度不高，无法建立电子结构与宏观性能的关系；后者处理多元体系时非常耗时。而先进的第一性原理合金理论EMTO-CPA方法，能够精确地描述组元成分连续变化的合金，是设计和筛选复杂合金的理想工具。本项目拟采用EMTO-CPA方法，阐明18种掺杂元素对钴基高温合金的电子结构的影响，以此为出发点研究合金的弹性性能、机械性能和电子结构的成分和温度依赖性，从而在电子层面上揭示钴基高温合金的性能的微观机制，为合理设计和筛选高性能的新型钴基高温合金提供科学的理论依据。

中文关键词： 钴基高温合金；合金设计；弹性性能；机械性能；第一性原理计算

英文摘要： Cobalt-based superalloys are newly developed high-temperature engineering materials. They exhibit superior hot corrosion, oxidation, and wear resistance compared to conventional Ni-based superalloys. Experimental studies have shown that discovery of the γ/γ' high-temperature strengthening offered novel Co-based superalloy higher strength and higher melting temperature corresponding to Ni-based superalloys. Such excellent high-temperature properties and mechanical properties make Co-based superalloys having huge potential applications in high-performance equipments such as aircraft engines and power-generation systems, etc. To achieve excellent structural materials, it is vital to optimize alloy components and their ratios. It is rather expensive and inefficient to design alloys using traditional trial-and-error tools. The molecular dynamics methods and traditional first-principles methods are not suitable to screen the alloys. The former cannot build a connection between electronical structures and macroscopic properties due to its low accuracy, whereas the latter becomes very time-consuming in the case of multicomponent systems. However, the advanced ab initio alloy theory as formulated within the EMTO-CPA method become the ideal choice when designing and screening complex alloys. The EMTO-CPA approach can acc

英文关键词： Co-based superalloy；alloy design；elastic properties；mechanical properties；first-principles calculation