The synthesis of composite powder precursors via chemical processes for the sintering of oxide dispersion-strengthened alloys
Oxide dispersion-strengthened (ODS) alloys are an important class of materials that are generally used in extreme working environments due to their outstanding high-temperature strength and creep resistance. The properties of ODS alloys greatly depend on the microstructure, such as the grain size of the alloy matrix, the morphology, size and distribution of the oxide second phase particles. Most ODS alloys are prepared by sintering, and the composite powder precursor consisting of metal and oxide is the primary factor for determining their microstructure and properties. Through chemical processes, these composite powder precursors with controllable size, shape and composition can be synthesized. Combined with proper sintering processes, it is possible to fabricate high-performance ODS alloys. In this review, several major chemical methods for preparing composite powder precursors for the sintering of ODS alloys are highlighted and their recent advances are expounded. Besides, the advantages and disadvantages of these methods are critically discussed to point out the feasible approach for the scalable production of high-performance ODS alloys.