Mechanical and oxidation properties of Ni sub 3 Al-based alloys

• Published in: Materials and manufacturing processes Vol. 16; no. 1; pp. 127 - 140
• Main Authors: Tsipas, D N, Lefakis, H, Rawlings, R D, Staton-Bevan, A, Tsipas, S A
• Format: Journal Article
• Language: English
• Published: 01.01.2001
• ISSN: 1042-6914

The effects of Hf and Co alloying additions on the mechanical properties of Ni sub 3 Al in the temperature range -197 deg C-1000 deg 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, RENE 80 and INC 718. The combined presence of Hf and Co additions to Ni sub 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 sub 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.