摘要
通过对镍基合金的组织形貌观察和X射线衍射分析,研究元素W及组织状态对镍基合金晶格常数及错配度的影响。结果表明,7.5%W镍基合金经完全热处理后,立方γ′相以共格方式嵌镶并均匀分布在γ基体相中。随元素W含量增加,合金中γ′和γ两相的合成衍射峰值略有左移,使γ′和γ两相的晶格常数增加,其中γ′相晶格常数增加幅度较大的原因是元素W较大比例地分布在γ′相中,并由此使合金中两相的晶格错配度由负值转变为正值。经完全热处理后,合金中γ和γ′两相有较小的晶格错配度,在高温拉伸蠕变期间外加应力的作用下,γ基体相的晶格常数值增加幅度较大,致使合金中γ′和γ两相晶格错配度的绝对值增加。
By means of microstructure observation and XRD diffraction analysis, the influence of element W and microstructure evolution on the lattice parameter and misfit of the nickel based superalloys was investigated. Results show that, after full heat treatment, the γ′ phase in the 7.5% W nickel based superalloy is coherently embedded and homogenously distributed in the γ, matrix phase. The diffraction peaks of the γ′, phases in the nickel based superalloy move towards left side with the increase of the element W, which results in the increase of the lattice parameters of γ′/γ phases. The reasons of the parameter increase of γ′ phase in the large extent is attributed to the more element W distributed in γ′ phase, which causes the misfit of γ′/γ phases to transform into the positive value from the negative value. After full heat treatment, a lower misfit value of γ′/γ, phases is displayed in the superalloy, and the parameter of phases increases in the large extent at the role of the applied stress during tensile creep, therefore increases the absolute value of the misfit of γ′/γ phases.
出处
《航空材料学报》
EI
CAS
CSCD
2008年第4期12-16,共5页
Journal of Aeronautical Materials
基金
国家自然科学基金资助项目(项目编号:50571070)
