Precipitation behavior of a novel cobalt-based superalloy subjected to prior plastic deformations

Abstract

The precipitation behavior of a novel cobalt-based superalloy subjected to prior plastic deformations was investigated in details by using field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), etc. The precipitation of a μ-phase, which appeared at temperatures of 1073–1373K, was confirmed, while MC-type carbide was observed at the temperatures >1173K. The prior plastic deformations promoted the precipitation of the μ-phase during subsequent aging. Further, the precipitation of the μ-phase at temperatures lower than 1173K was confirmed to occur predominantly along the {111} slip bands; this was the dominant deformation mechanism of this alloy during plastic deformation. In contrast, there was no evidence that the precipitation of the MC-type carbide was affected by the prior plastic deformations in the case of the specimens exposed at 1273 and 1373K.