Ti和Ta的协同作用对新型钴基单晶高温合金组织与蠕变行为的影响机理

项目名称： Ti和Ta的协同作用对新型钴基单晶高温合金组织与蠕变行为的影响机理

项目编号： No.51301014

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： 王美玲

作者单位： 北京科技大学

项目金额： 25万元

中文摘要： 钴基高温合金具有更为优异的抗热腐蚀和耐热疲劳性能，但由于缺乏γ'相强化机制，其高温强度和承温能力显著低于镍基合金，只能用于先进燃机的静子部件。近年来，Co-Al-W合金系中γ'高温稳定相的发现，为新型钴基高温合金的发展开辟了一条新道路，并迅速成为国际高温合金界的研究热点之一。 课题组前期研究结果发现Ti和Ta元素的协同作用能显著提高γ'相的稳定存在温度，有可能使合金比现有同类钴基合金的承温能力提高50℃。因此，本项目以Co-Al-W(-Ti-Ta)单晶高温合金为研究对象，从合金元素的成分分配比出发，系统研究Ti、Ta元素独立及协同作用对合金组织结构、高温组织稳定性、蠕变行为的影响规律，阐明Ti和Ta的协同作用显著提高γ'相高温稳定性的机理及其对合金蠕变行为的影响机制等两个关键科学问题，为发展更高承温能力、理想两相组织和优异蠕变性能的新一代钴基单晶高温合金提供理论基础和实验数据。

中文关键词： 钴基高温合金；蠕变行为；位错；；

英文摘要： Although Co-base superalloys exhibit superior hot corrosion and thermal fatigue resistance, they are only used for stationary components in advanced gas turbines due to their significant lower high-temperature strength and temperature capability than those of Ni-base superalloys with γ′ strengthening precipitates. Recently, similar γ′ phase with high-temperature stability have been reported in Co-Al-W system, which provides a pathway for the development of this new class of Co-base alloys. Our previous research showed that the synergetic effects of Ti and Ta pronouncedly increased γ′ solvus temperature, which might improve the temperature capability by 50℃ for this class of alloys. In the current study, both individual and synergetic effects of Ti and Ta on microstructure, phase stability and creep behavior will be investigated systematically in a series of Co-Al-W(-Ti-Ta) single crystal alloys, initiated from the analyses of elemental partitioning ratios. The synergetic effect of Ti and Ta on high temperature stability of γ′ phase and creep deformation mechanism will be clarified. This project will provide a fundamental understanding and experimental data accumulation for further developing this new generation Co-base single crystal superalloys with high temperature capability, desired γ/γ′ two-phase microstr

英文关键词： Co-base alloy；Creep behavior；Dislocation；；