摘要
采用电子束物理气相沉积技术制备一种新型镍基高温合金薄板。并通过显微硬度计和透射电镜研究该合金在不同时效温度下室温显微硬度的变化以及γ′相粗化行为和形貌演化。结果表明,随着时效温度升高,γ′相的形貌按“台阶机制”由最初的近似球形颗粒逐渐粗化成规则排列的立方体形貌,符合体扩散控制的“Ostwald”熟化规律,粗化激活能为266.18kJ.mol-1。同时由于合金中γ′相的粗化,室温显微硬度不断降低,合金被软化。
The sheet metal of a new Ni-based superalloy was prepared by Electron Beam Physical Vapor Deposition （EBPVD） technology. Microhardness tester and transmission electron microscope were used to study the change of room temperature microhardness, coarsening behavior and morphological change of γ′ precipitates. Results show that γ′ precipitates coarsened by the step growth mechanism change from approximately round shape to regular order cubic one with the increase of aging temperature. Growth of γ′ precipitates proceeds by Ostwald ripening controlled by volume diffusion of solute atoms. The activation energy for growth are evaluated as 266.18kJ· mol^-1 for this alloy. The decrease in room temperature microhardness and the softening of alloy can be attributed to the growth of γ′ precipitates in the alloy.
出处
《航空材料学报》
EI
CAS
CSCD
2006年第6期38-41,共4页
Journal of Aeronautical Materials
基金
国家自然科学基金项目(9020503490405016)
关键词
电子束物理气相沉积
镍基高温合金
γ′相
粗化
Ostwald熟化
electron beam physical vapor deposition
nickel-based superalloy
gamma prime precipitate
coarsening
Ostwald ripening
