含Sc粉末高温合金的成分设计及其强化机理

One of the bottlenecks restricting the development of aircraft turbines was the P/M superalloy fabrication in our country. The features of multiple components, long preparation process, multiple processes and complex conditions brought great challenges to the alloy design and process development. Sc element was widely used in Al, Mg and other alloys due to its characteristics of large atomic radius and low density. In the preliminary work of the project team, it was found that the addition of Sc effectively improved the property of superalloy. Based on this, through machine-learning and iterative optimization, the project needs to determine the optimal composition range. Adopting powder-canning and hot extrusion technology, the short preparation process was designed to prepare the Sc addition P/M superalloy. And then, this work mainly present the APT, SANS, SR-HEXRD methods, and combined with the first principles calculations, to study the existence form and distribution characteristics of the Sc, and to clarify the effect mechanism of γ/γʹ interface interaction and stability of the γʹ under the influence of Sc addition. In order to reveal the high-temperature strengthening mechanism, the modification effect of solute atoms, grain refinement and the second phase after the Sc addition was considered and the unified strength prediction model was established. As a result, the independent composition of Sc addition P/M superalloy was obtained and the technical of short process preparation for P/M turbine disk was formed, which provides new ideas and theoretical support for the superalloy composition design and process development

涡轮盘用粉末高温合金仍然是制约我国航空发动机发展的瓶颈问题之一，其组成元素多、制备流程长、工艺环节控制复杂的特点，为其合金设计和工艺开发带来极大的挑战。Sc元素以其原子半径大、密度低的特点，被广泛应用于Al、Mg等合金，本项目团队前期工作发现，Sc的引入有效提高了高温合金性能。基于此，本项目拟通过机器学习迭代优化，确定Sc添加的最优选择，采用粉末包套直接热挤压技术，开展短流程制备工艺设计研究，运用APT、SANS、SR-HEXRD等表征手段，结合第一性原理计算，探明Sc的存在形式、分布特征，阐明Sc的存在形式对γ/γʹ相界面交互作用、γʹ相稳定性的影响机制，揭示其高温强化机理，并综合考虑Sc引入带来的溶质原子、晶粒细化、第二相改性作用，建立统一强度预测模型。由此，获得含Sc粉末高温合金的自主成分，形成粉末涡轮盘短流程制备的技术原型，为高温合金成分设计及工艺开发提供新的思路和理论支撑。

涡轮盘用粉末高温合金仍然是制约我国航空发动机发展的瓶颈问题之一，其组成元素多、制备流程长、工艺环节控制复杂的特点，为其合金设计和工艺开发带来极大的挑战。Sc元素以其原子半径大、密度低的特点，被广泛应用于Al、Mg等合金，本项目团队前期工作发现，Sc的引入有效提高了高温合金性能。基于此，本项目通过机器学习实现了含Sc粉末高温合金的成分优选；采用粉末包套直接热挤压技术，开展短流程制备工艺设计研究，运用APT、EBSD、TEM、EPMA等表征手段，探明了Sc的存在形式、分布特征，阐明了Sc的存在形式对γ/γʹ相界面交互作用、γʹ相稳定性的影响机制，揭示其高温强化机理，并综合考虑Sc引入带来的溶质原子、晶粒细化、第二相改性作用，建立统一强度预测模型。由此，获得含Sc粉末高温合金的自主成分，形成粉末涡轮盘短流程制备的技术原型，为高温合金成分设计及工艺开发提供新的思路和理论支撑。