Impact Factor:2.9
DOI number:10.3390/met13030611
Affiliation of Author(s):中南大学粉末冶金研究院
Teaching and Research Group:高温结构材料研究所
Journal:Metals
Funded by:国家科学技术大项目（J2019-IV-0003-0070）、中国自然科学基金（91860105、52074366）、中国湖南省自然科学基金（2021JJ40757）、湖南省科技创新计划（2021RC3131）
Key Words:Ni-based superalloy, Scandium, Grain, Gamma' precipitate, Tensile property
Abstract:In this work, a method concerning thermal consolidation is proposed to simulate the traditional powder metallurgy process and accomplish the composition screening of powder metallurgy Ni-based superalloys U720Li and RR1000 with rare metal scandium, and superalloys with zero scandium addition, medium scandium addition and high scandium addition are selected. Then effects of scandium on the microstructure and mechanical properties of superalloys are further investigated through fast hot pressed sintering. The results indicate that scandium doping can effectively refine the grain through modifying the size and volume fraction of primary ?' precipitates at the grain boundary. Meanwhile, scandium can promote the growth and precipitation of secondary ?' precipitates to some extent. Due to the comprehensive effects of ?' precipitate modification and grain boundary strengthening, as-sintered U720Li with 0.043 wt.% scandium presents an excellent combination of tensile strength and ductility at ambient and elevated temperature while as-sintered RR1000 with 0.064 wt.% scandium has a good performance at elevated temperature.
Co-author:Feng Liu, Heng Dong, Xiaoqiong Ouyang, Xiangyou Xiao, Lan Huang
First Author:Lin Ye
Indexed by:Article
Correspondence Author:Liming Tan, Lan Huang
Document Code:611
Discipline:Engineering
First-Level Discipline:冶金
Volume:13
Issue:3
ISSN No.:2075-4701
Translation or Not:no