|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Materials Science for High-Performance Permanent Magnets
||Microstructural Characterization of Magnetic MnAl Alloys
||Merve Genc, Ozgun Acar, Ilkay Kalay,
|On-Site Speaker (Planned)
Rare-earth free Mn-Al permanent magnet alloys exhibit an attractive combination of magnetic properties for several technological applications. Its magnetism arises from a metastable tetragonal tau-phase originated from a hexagonal close-packed epsilon-phase. Even though there are many theories postulated on the transformation mechanism from epsilon-to-tau phase, the answer is still unclear. At a given composition one can favor one mode over the other by choosing the appropriate composition and annealing temperature. It was observed that transformation sequence and the corresponding magnetic properties has been profoundly affected by the existence of an intermediate ε prime phase. We found that epsilon prime can be retained upon quenching for a narrow range of composition which yields to direct formation of ferromagnetic tau. The predominant phase transformation mode of ferromagnetic tau from retained epsilon prime phase will be discussed in details based on in-situ, conventional and high-resolution TEM analyses.