K.Y.Cheng
,
D.H.Kim
,
Y.S.Yoo
,
C.Y.Jo
,
T.Jin
,
Z.Q.Hu
材料科学技术（英文）
Microstructural stability of a nickel base single crystal alloy DD8 has been investigated. Standard heat treated specimen showed good microstructural stability at 950℃. While under the as-cast condition, a kind of rod-like phase precipitated in the interdendritic region of as-cast specimen during thermal exposure. The phase, which has bcc structure, was enriched with Cr. Thermo-calc also predicted precipitation of a bcc phase at around 950℃. The Cr-rich bcc phase was considered as α-Cr and formed due to the segregation of Cr under the as-cast condition.
关键词:
DD-8
,
null
,
null
,
null
F.M.Yang
,
X.F.Sun
,
H.R.Guan
,
Z.Q.Hu
金属学报(英文版)
The dynamic strain aging behavior during tensile tests of K40S alloy has been investigated in the temperature range of 25-1100℃ with the strain rate range from 10^-4 to 10^-3s^-1. The results show that four different types of serration, identified as A,B, C and E type serration were observed in the temperature range of 300-500℃. The strain exponents for onset of the serrated flow were calculated as 1.21, 2. 79 and 1.61,and the activation energies as 121, 40 and 67kJ/mol for E, B and C type serration respectively. The main mechanism for dynamic strain aging discussed in light of the strain exponent and the activation energy.
关键词:
dynamic strain aging
,
null
,
null
