Singh, N. and Shyam, R. and Upadhyay, N. K. and Dhar, A. (2015) Development of Rare-Earth Free Mn-Al Permanent Magnet Employing Powder Metallurgy Route. In: INTERNATIONAL CONFERENCE ON MATERIALS SCIENCE AND TECHNOLOGY (ICMST 2012) , JUN 10-14, 2012, Kerala, INDIA .

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Abstract

Most widely used high-performance permanent magnets are currently based on intermetallics of rare-earths in combination with Fe and Co. Rare-earth elements required for these magnets are getting expensive by the day. Consequently, there is a thrust worldwide to develop economical rare-earth free permanent magnets. It is acknowledged that the phase in Mn-Al alloys possesses magnetic properties without the presence of ferromagnetic elements such as Fe, Co, and Ni. In the present study, we report the synthesis of magnetic phase of Mn54Al46 alloy synthesized using mechanical alloying followed by solutionizing and annealing to obtain the desired magnetic phase. It is well known that Al dissolves partially in Mn matrix hence supersaturated solid solution of Mn54Al46 alloy powder was obtained by mechanical alloying using a planetary high-energy ball mill. For this purpose elemental Mn and Al powders were ball-milled in Argon atmosphere at 400 rpm using stainless steel bowl with ball to powder ratio of 15:1. These mechanically alloyed Mn54Al46 powders were then consolidated using spark plasma sintering at 550 degrees C for 20 min. followed by solution treatment at 1050 degrees C for 5 hrs and then water quenched to retain high temperature phase. Subsequently, the Mn54Al46 samples were annealed in the temperature range 450 degrees C-650 degrees C to obtain the magnetic phase. These samples were characterized by XRD and SEM and the magnetic properties were measured using a vibrating sample magnetometer (VSM). It was observed that the magnetization and coercivity of MnAl magnets exhibited strong dependence on annealing temperature and annealing

Item Type:	Conference or Workshop Item (Paper)
Subjects:	Materials Science
Divisions:	UNSPECIFIED
Depositing User:	Dr. Rajpal Walke
Date Deposited:	21 Sep 2016 10:56
Last Modified:	21 Sep 2016 10:56
URI:	http://npl.csircentral.net/id/eprint/1764

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