Effect of Process on Microstructure and Elevated Temperature Mechanical Behavior of Multi-Phase NiAl-Fe(Nb) Alloy
The microstructure and elevated temperature mechanical behavior of as-cast, HIPed and directionally solidified NiAl-Fe(Nb) Alloys have been investigated. The results show that the microstructure of as-cast NiAl-Fe(Nb) alloy consists of dendritic regions (b) and interdendritic regions (g/g¢) with non-continuous NbNiAl(Laves) phase segregating at the interfaces of b and g/g¢ phases. The HIP processing does not alter the microstructure of as-cast alloy. The longitudinal dendritic microstructure of the DS NiAl-Fe(Nb) alloy is regular. Room temperature elongations of as-cast and HIPed NiAl-Fe(Nb) alloys are all zero, however, 0.4% for the DS alloy. The strength and elongation of the HIPed alloy are higher than that of as-cast alloy. The yield strength and ultimate strength of the DS alloy are equivalent to that of as-cast alloy, but elongation of the DS alloy is higher than that of as-cast alloy, the elongation exceed 100% at 1273K, which indicates that the DS alloy can be deformed superplastically.
Jianzhong Wang and Jingang Qi
P. Han and J. T. Guo, "Effect of Process on Microstructure and Elevated Temperature Mechanical Behavior of Multi-Phase NiAl-Fe(Nb) Alloy", Advanced Materials Research, Vols. 299-300, pp. 163-166, 2011