摘要
本文系统地研究了凝固速度对一种新研制的抗热腐蚀镍基单晶高温合金凝固组织与溶质再分配的影响。结果表明,随着凝固速度的增加,枝晶间距显著降低,显微疏松大大减少,溶质元素偏析程度明显减轻,γ/γ′共晶尺寸减小,共晶形态从几乎全由粗大初生γ′团块组成的大板团或长条板状逐渐向内部组织极其精细均匀的层片状或筛网状转化。最后指出,要获得枝晶细小、组织致密、元素偏析小且易于均匀化的单晶高温合金凝固组织,应尽可能加快凝固速度。
The effect of solidification rate on the microstructure and solute redistribution of a newly developed hot corrosion-resistant single-crystal Ni-base superalloy was studied under commercial production conditions. Results show that solidification rate has strong effect on the solidified structure and solute segregation. As solidification rate increases, the primary and secondary dendrite arm spacings decrease markedly, the volume fraction and average dimension of interdendritic microporosity reduce considerably, the solute segregation improves effectively, and the morphology of interdendritic γ/γ′ eutectic varies gradually from large packets which are actually the aggregates of coarse primary γ′ blocks to nodules of superfine lamellar or screen-like structure of γ and γ′ phases. It is concluded that a solidification rate as high as possible should be used in order to obtain the solidified structure with fine dendrite arm spacing, low microporosity and uniform chemical homogeneity.
出处
《航空材料学报》
EI
CAS
CSCD
1991年第1期12-18,共7页
Journal of Aeronautical Materials
基金
国家自然科学基金
