Synthesis of dispersion-strengthened alloys by the activated reactive evaporation process from a single rod-fed electron beam source

Abstract

Oxide-dispersion-strengthened alloys have better high-temperature properties but poorer low-temperature strength compared to Ni-base super alloys. Relative to these alloys, dispersion-strengthened alloys of titanium carbide dispersed in a Ni-base alloy matrix have been found to have good low- as well as high-temperature strength. This investigation was concerned with the synthesis of dispersion-strengthened alloys of TiC particles in a Ni matrix using the activated reactive evaporation (ARE) process. A Ni–Ti alloy rod was evaporated from an electron beam source in the presence of C2H2, all of the vapor species being activated or partially ionized using the ARE process. The deposits were characterized by x-ray diffraction, electron microprobe analysis, microhardness, and transmission electron miscroscopy of carbon replicas. It was established that Ni–TiC dispersion-strengthened alloys were produced by ARE process. The microhardness of the alloys decreased when annealed at high temperatures due to particle coarsening.