TY - JOUR
T1 - Precipitation behavior and chemical composition of secondary γ‛ precipitates in a Re-containing Ni-based single crystal superalloy
AU - Qu, Pengfei
AU - Yang, Wenchao
AU - Qin, Jiarun
AU - Liu, Chen
AU - Cao, Kaili
AU - Zhang, Jun
AU - Liu, Lin
N1 - Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2020/4
Y1 - 2020/4
N2 - Three-dimensional atom-probe tomography and scanning electron microscopy were utilized for an in-depth examination of the formation of secondary γ′ precipitates and the composition difference between secondary γ′ precipitates and primary γ′ precipitates in a Re-containing Ni-based single crystal superalloy. It was found that the secondary γ′ precipitates was formed during the air cooling after primary aging of 1180 °C/4h and would grow up during the secondary aging at 870 °C. Al and Ta were mainly distributed in γ′ precipitates (including the primary and the secondary γ′ precipitates) and Mo, Cr, Co and Re were more distributed in γ matrix. Compared with the primary γ′ precipitates, the secondary γ′ precipitates contained more γ-forming elements, such as Re, Cr, W and Mo, while the content of Ta was less. The distribution of W in the secondary γ′ precipitates was much higher than that in the primary γ′ precipitates and was equal to that in γ matrix. Based on the diffusion constant of alloying elements in Ni, the diffusion distance of various elements was as followed during the air cooling after primary aging: Re < W < Co < Mo < Ni < Ta < Cr < Al. The insufficient diffusion distance of γ-forming elements was an important factor leading to their enrichment in the secondary γ′ precipitates. And the Re element might hinder the diffusion of other γ-forming elements, such as Cr and Mo.
AB - Three-dimensional atom-probe tomography and scanning electron microscopy were utilized for an in-depth examination of the formation of secondary γ′ precipitates and the composition difference between secondary γ′ precipitates and primary γ′ precipitates in a Re-containing Ni-based single crystal superalloy. It was found that the secondary γ′ precipitates was formed during the air cooling after primary aging of 1180 °C/4h and would grow up during the secondary aging at 870 °C. Al and Ta were mainly distributed in γ′ precipitates (including the primary and the secondary γ′ precipitates) and Mo, Cr, Co and Re were more distributed in γ matrix. Compared with the primary γ′ precipitates, the secondary γ′ precipitates contained more γ-forming elements, such as Re, Cr, W and Mo, while the content of Ta was less. The distribution of W in the secondary γ′ precipitates was much higher than that in the primary γ′ precipitates and was equal to that in γ matrix. Based on the diffusion constant of alloying elements in Ni, the diffusion distance of various elements was as followed during the air cooling after primary aging: Re < W < Co < Mo < Ni < Ta < Cr < Al. The insufficient diffusion distance of γ-forming elements was an important factor leading to their enrichment in the secondary γ′ precipitates. And the Re element might hinder the diffusion of other γ-forming elements, such as Cr and Mo.
KW - Composition
KW - Elemental distribution
KW - Ni-based single crystal superalloy
KW - Precipitation
KW - Secondary γ′ precipitates
KW - Three-dimensional atom probe tomography
UR - http://www.scopus.com/inward/record.url?scp=85078944777&partnerID=8YFLogxK
U2 - 10.1016/j.intermet.2020.106725
DO - 10.1016/j.intermet.2020.106725
M3 - 文章
AN - SCOPUS:85078944777
SN - 0966-9795
VL - 119
JO - Intermetallics
JF - Intermetallics
M1 - 106725
ER -