High-Performance MnBi Alloy Prepared Using Profiled Heat Treatment

Journal Article · Mon Dec 01 04:00:00 EST 2014 · IEEE Transactions on Magnetics

DOI:https://doi.org/10.1109/tmag.2014.2341659· OSTI ID:1225170

Nguyen, Van V.; Poudyal, Narayan; Liu, Xubo; Liu, J. Ping; Sun, Kewei; Kramer, Matthew J.; Cui, Jun

The profiled heat treatment (PHT) method has been used to synthesize MnBi alloys with high-purity low-temperature phase (LTP). In the PHT method, the arc-melted MnBi alloy was remelted then slowly cooled by a pseudo-equilibrium solidification process to promote the formation of LTP phase. The PHT-treated MnBi alloys had an LTP phase up to 94 wt.% and a magnetization of 73 emu/g under a field of 9 T. Scanning electron microscopy showed that there exist some micrometer-sized Mn-rich inclusions in the LTP matrix of the PHT MnBi alloy. The PHT MnBi alloys were crushed into powders with an average size of ~3 μm by low-energy ball milling. These MnBi powders were aligned in an 18 kOe field and warm compacted into a bulk magnet at 300 °C for 30 min. The magnet had a density of 8.2 g/cm3 and magnetic properties of Ms = 6.7 kG, Mr = 5.3 kGs, i Hc = 5 kOe, and (BH)max = 6.1 MGOe

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1225170
• Report Number(s): PNNL-SA-110266; CJ0100000
• Journal Information: IEEE Transactions on Magnetics, Journal Name: IEEE Transactions on Magnetics Journal Issue: 12 Vol. 50; ISSN 0018-9464
• Publisher: Institute of Electrical and Electronics Engineers. Magnetics Group
• Country of Publication: United States
• Language: English

Related Subjects

MnBi
PHT
permanent magnet
profiled heat treatment