HIGH-TEMPERATURE STRENGTH OF NI-DOPED IRAL WITH THE B2 TYPE ORDERED CRYSTAL-STRUCTURE

Constant-velocity and constant-load compression tests have been conduc ted to examine the mechanical behavior of polycrystalline Ir1-xNixAl i ntermetallic compounds with x=0 to 1.0 at elevated temperatures. Ducti lity of Ir1-xNixAl is improved with increasing x, while the strength d ecreases with increasing x in the intermediate temperature range. The specific strength of Ir1-xNixAl is almost independent of x at temperat ures higher than approximately 1473 K. Secondary creep of IrAl and Ir0 .2Ni0.8Al (i.e. modified NiAl) exhibits class II and class I behavior, respectively. Creep strength of Ir1-xNixAl is about a magnitude of fo ur higher than that of single-phase and multi-phase NiAl at a given ap plied stress. The Ir1-xNixAl intermetallic compound is superior to bin ary IrAl as a high-temperature structural material from the viewpoint of the specific strength, ductility and resistance to oxidation, espec ially at temperatures higher than 1473 K. Published by Elsevier Scienc e Limited. All rights reserved.