Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing
The ordered intermetallic compound β-NiAl and its pseudo-binary off-eutectic alloys with 1 at.% tungsten and 9.7 at.% chromium were directionally solidified (DS) in the ‘floating-zone’ mode, and tested for compressive strength and fracture behavior in the temperature range 300–800 K. The dual-phase structures created by the DS of ternary NiAl alloys led to improvements in both the compressive strength and the ductility. The room-temperature (300 K) 0.2% compressive yield strength (CYS) of DS NiAl(W) (623 MPa) is larger than the CYS of DS NiAl(Cr) (565 MPa) and DS NiAl (435 MPa). The CYS of the three alloys dropped with increasing test temperature, and at 800 K, the CYS values for the three materials were comparable (356, 315 and 344 MPa for NiAl, NiAl(W) and NiAl(Cr), respectively). All the DS alloys exhibited greater than near-zero ductility of polycrystalline β-NiAl at room-temperature, with the fracture strain being the largest for the DS NiAl(Cr) (16.6%), followed by DS NiAl(W) (9.8%) and DS NiAl (7.33%). The strength and ductility data and fractography of test specimens suggest that ductile-phase toughening and second-phase strengthening are responsible for the observed improvements in the ductility and strength of NiAl. Limited tensile tests on the DS NiAl and DS NiAl(Cr) indicate that the CYS is greater than the tensile yield strength.
Asthana, R.; Tiwari, R.; and Tewari, Surendra N., "Compressive Properties of Zone-Directionally Solidified β-NiAl and Its Off-Eutectic Alloys With Chromium and Tungsten" (2002). Chemical & Biomedical Engineering Faculty Publications. 63.
Asthana, R., Tiwari, R., , & Tewari, S. (2002). Compressive properties of zone-directionally solidified β-NiAl and its off-eutectic alloys with chromium and tungsten. Materials Science and Engineering: A, 336(1-2), 99 - 109.
NOTICE: this is the author’s version of a work that was accepted for publication in Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, [336, 1-2, (October, 25, 2002)] DOI 10.1016/S0921-5093(01)01919-0