Microstructure and Magnetic Properties of Bulk Nanocrystalline MnAl

作者：Chaturvedi Anurag; Yaqub Rumana; Baker Ian^*

来源：Metals, 2014, 4(1): 20-27.

DOI：10.3390/met4010020

• permanent magnet
• equal channel angular extrusion
• mechanical milling
• magnetic properties
• high coercivity

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 tau phase, with some of the equilibrium gamma(2) and beta 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.

• 出版日期2014-3