The microstructures of multiphase Ni-20Al-30Fe and its constituent phases
- Dartmouth Coll., Hanover, NH (United States). Thayer School of Engineering
The microstructures of the multiphase ({beta}{prime} + {gamma}/{gamma}{prime}) alloy Ni-20Al-30Fe (in at.%) and alloys similar to its constituent {beta}{prime} (Ni-30Al-20Fe) and {gamma}/{gamma}{prime} (Ni-12Al-40Fe) components, processed through a casting and hot-extrusion route, were studied after water quenching following annealing at 700 K, 900 K, and 1,100 K. The microstructures at 700 K and 900 K were similar to the room temperature microstructure, consisting of a {beta}{prime} pro-eutectic phase and a eutectic of {beta}{prime} and {gamma}/{gamma}{prime} phases (0.5{mu}m lamellae width). However, at 1,100 K, the {gamma}{prime} dissolved. The nominally Ni-12Al-40Fe alloy was determined, using energy dispersive x-ray spectroscopy, to be of composition Ni-15Al-37Fe. The alloy exhibited a {gamma}/{gamma}{prime} microstructure at all test temperatures that was consistent with the phase diagram for the latter composition; the {gamma}{prime} precipitates were observed to coarsen with increasing temperatures. The {beta}{prime} alloy, Ni-30Al-20Fe, exhibited an equiaxed microstructure at room temperature with a thin ({approximately} 10 nm), discontinuous iron-rich grain boundary film. At 900 K, the microstructure was three-phase, {beta}{prime} + {gamma}/{gamma}{prime}, instead of two-phase, {beta}{prime} + {gamma}, as predicted by the isotherms. At 1,100 K, however, the microstructure was two-phase {beta}{prime} + {gamma}, which was consistent with the isotherms.
- OSTI ID:
- 49178
- Journal Information:
- Materials Characterization, Journal Name: Materials Characterization Journal Issue: 3 Vol. 34; ISSN 1044-5803; ISSN MACHEX
- Country of Publication:
- United States
- Language:
- English
Similar Records
Deformation and fracture behavior of a directionally solidified {beta}/{gamma}{prime} Ni-30 at. pct. Al alloy
Microstructure investigation in B2-phased Ni-25Al-40Fe intermetallic compound