|About this Abstract
||MS&T23: Materials Science & Technology
||Interface-mediated Phenomena in Structural Materials
||Experimental Constraints on the Grain Growth Kinetics of Rhenium
||Christopher Thom, Todd Leonhardt
|On-Site Speaker (Planned)
We performed grain growth experiments on pure rhenium metal in a hydrogen atmosphere at temperatures from 1450°C to 1750°C. Our results suggest a fundamental change in the kinetics of grain growth between sintered and cold worked rhenium. With our currently available data, we estimate the grain growth exponent p in both sets of data to be approximately 10, which is markedly different from the canonical theoretical values of 2-4. This large value of p likely originates from an additional drag force imparted by porosity on the grain boundaries, which is not accounted for in most theoretical derivations of grain growth kinetics. These results indicate that the driving force for grain growth in sintered and cold worked rhenium is different at the range of conditions tested. However, without further experiments and detailed microstructural analyses, we cannot definitively identify the driving microphysics or rule out the possibility of a two-stage mechanism.