Creep behavior of near-stoichiometric polycrystalline binary NiAl

New and published constant load creep and constant engineering strain rate data on near-stoichiometric binary NiAl in the intermediate temperature range 700 to 1300 K are reviewed. Both normal and inverse primary creep curves are observed depending on stress and temperature. Other characteristics relating to creep of NiAl involving grain size, stress and temperature dependence are critically examined and discussed. At stresses below 25 MPa and temperatures above 1000 K, a new grain boundary sliding mechanism was observed with n similar to 2, Q(c) similar to 100 kJ mol(-1) and a grain size exponent of about 2. It is demonstrated that Coble and current accommodated grain boundary sliding models fail to predict the experimental creep rates by several orders of magnitude.