ABSTRACT
Oxide dispersion-strengthened (ODS) alloys have long been known to have oxidation resistance that is, in general, superior to that of conventional alloys developed for high-temperature applications. This gave rise to the expectation that ODS materials could be used at elevated temperatures without a protective coating to prevent excessive oxidation. Such a belief was based on the early oxidation data on thoria dispersion-strengthened nickel (TD-Ni)• and thoria dispersion-strengthened nichrome (TD-NiCr) measured in isothermal and cyclic, static air tests. Both alloys were developed by DuPont and later Fansteel during the 1960s. This work seemed to indicate that alloys such as TD-NiCr and DSNiCr (the Sherrit Gordon Incorporated version of the Sl\flle alloy) had potential for use uncoated at temperatures as high as 1473 K. TD-Ni, on the other hand, even though exhibiting an oxidation rate slightly lower than that of pure nickel (Wlodek, 1962; Jones and Westerman, 1963; Pettit and Felten, 1964; Lowell et al., 1972), still oxidized at a rate which was inadequate for use without a protective coating. Much of this early work has been summarized by Wright (1972).
