MECHANICAL AND OXIDATION PROPERTIES OF Ni3Al-BASED ALLOYS

• Published in: Materials and manufacturing processes 2001-01, Vol.16 (1), p.127-140
• Main Authors: Tsipas, D. N., Lefakis, H., Rawlings, R. D., Staton-Bevan, A., Tsipas, S. A.
• Format: Article
• Language: English
• ISSN: 1042-6914; 1532-2475
• DOI: 10.1081/AMP-100103702

The effects of Hf and Co alloying additions on the mechanical properties of Ni 3 Al in the temperature range −197°C-1000°C, and on the hot cyclic oxidation resistance of this alloy are presented. Shown also are the effects of Al and Hf-containing surface coatings on the hot cyclic corrosion resistance of two Ni-based commercial alloys, RENÉ 80 and INC 718. The combined presence of Hf and Co additions to Ni 3 Al seems to effect a definite improvement in the yield strength throughout the above temperature range. Hf, on the other hand, turns out to be the single most important addition, whether present in the bulk of the Ni 3 Al alloy or in the protective surface coating of the Ni-based alloys. Significant improvements are imparted in both cases, i.e., hot cyclic oxidation resistance and hot cyclic corrosion resistance, respectively. The positive effects of the above additions are discussed in relation to the various known mechanisms.