|About this Abstract
||Materials Science & Technology 2020
||High Entropy Materials: Concentrated Solid Solution, Intermetallics, Ceramics, Functional Materials and Beyond
||Effect of Milling Parameters on Microstructure and Mechanical Properties of Mechanically Alloyed, Refractory High Entropy Alloy
||Joshua A. Smeltzer, Christopher J. Marvel, B. Chad Hornbuckle, Anit Giri, Kristopher A. Darling, Martin P. Harmer
|On-Site Speaker (Planned)
||Joshua A. Smeltzer
Mechanical alloying is an effective method to synthesize high strength, nano-structured HEAs. However, contamination is still an obstacle as it is difficult to predict properties based purely on thermodynamic considerations. Herein, four derivatives of a refractory MoNbTaW HEA, which is predicted as a single phase, were synthesized by altering milling media (tool steel and WC) and cryogenic liquid (N2 and Ar) to elucidate the effect of milling parameters on phase formation and mechanical properties. Light element contamination was measured using combustion gas techniques and microstructures of annealed alloys were characterized using aberration-corrected scanning transmission electron microscopy. Initial results show impurity concentrations vary up to 1 at.% under different milling conditions, thereby stabilizing distinct, multi-phase microstructures, and producing hardnesses that range 5 GPa. Overall, it is critical to understand and potentially control the effect of milling parameters (i.e. contamination) towards microstructural evolution and mechanical behavior of mechanically alloyed HEAs.