1. School of Electromechanism Engineering, Hunan University of Science and Technology, Xiangtan 411201, Hunan, China; 2. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, Liaoning, China
Superplasticity of Directionally Solidified NiAl-15Cr Alloy at High Temperature
1. School of Electromechanism Engineering, Hunan University of Science and Technology, Xiangtan 411201, Hunan, China; 2. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, Liaoning, China
ժҪ Ni-25Al-15Cr (atomic percent, %) alloy was directionally solidified (DS) under argon atmosphere in an Al2O3-SiO2 ceramic mold by standard Bridgman method. The microstructure of the as-fabricated alloy was studied using optical microscope, X-ray diffractometer, and scanning electron microscope. The alloy consisting of dendritic -NiAl phase, interdendritic  phase, and transient layer  phase, has been investigated. This alloy exhibits superplastic deformation behavior at 1 273−1 373 K over an initial strain rate range of 8.35��10-4−1.67��10-2 s-1. The maximum elongation of 280% with strain rate sensitivity index m=0.22 was obtained at the temperature of 1 323 K and an initial strain rate of 8.35��10-3 s-1. Transmission electron microscopy (TEM) observations indicate that the superplastic deformation stems from the balance between high resistance (by dislocation sliding) and strain softening (by dynamic recovery and recrystallization).
Abstract��Ni-25Al-15Cr (atomic percent, %) alloy was directionally solidified (DS) under argon atmosphere in an Al2O3-SiO2 ceramic mold by standard Bridgman method. The microstructure of the as-fabricated alloy was studied using optical microscope, X-ray diffractometer, and scanning electron microscope. The alloy consisting of dendritic -NiAl phase, interdendritic  phase, and transient layer  phase, has been investigated. This alloy exhibits superplastic deformation behavior at 1 273−1 373 K over an initial strain rate range of 8.35��10-4−1.67��10-2 s-1. The maximum elongation of 280% with strain rate sensitivity index m=0.22 was obtained at the temperature of 1 323 K and an initial strain rate of 8.35��10-3 s-1. Transmission electron microscopy (TEM) observations indicate that the superplastic deformation stems from the balance between high resistance (by dislocation sliding) and strain softening (by dynamic recovery and recrystallization).
ZHANG Guang-ye;;ZHANG Hua;ZHANG Hou-an;WU Xian-ming;GUO Jian-ting. Superplasticity of Directionally Solidified NiAl-15Cr Alloy at High Temperature[J]. �й������ڿ���, 2006, 1(4): 0-0.
ZHANG Guang-ye;;ZHANG Hua;ZHANG Hou-an;WU Xian-ming;GUO Jian-ting. Superplasticity of Directionally Solidified NiAl-15Cr Alloy at High Temperature. Chinese Journal of Iron and Steel, 2006, 1(4): 0-0.
2006, Vol. 1 