Microstructure and Magnetic Properties of Bulk Nanocrystalline MnAl

Metals

Anurag Chaturvedi¹  Rumana Yaqub¹ 

[1] Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA;

关键词: permanent magnet;    equal channel angular extrusion;    mechanical milling;    magnetic properties;    high coercivity;   

DOI  :  10.3390/met4010020

来源: mdpi

【 摘 要 】

MnAl is a promising rare-earth free permanent magnet for technological use. We have examined the effects of consolidation by back-pressure, assisted equal channel angular extrusion processing on mechanically-milled, gas-atomized Mn-46% at. Al powder. X-ray diffraction showed both that the extruded rod consisted mostly of metastable τ phase, with some of the equilibrium γ₂ and β phases, and that it largely retained the as-milled nanostructure. Magnetic measurements show a coercivity of ≤4.4 kOe and a magnetization at 10 kOe of ≤40 emu/g. In addition, extrusions exhibit greater than 95% of the theoretical density. This study opens a new window in the area of bulk MnAl magnets with improved magnetic properties for technological use.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.