Development of NdFeB Magnet through Hydrogen Decrepitation
Neodymium based magnets are the powerful permanent magnet of today.\nThis paper will discuss iron based rare earth magnets. NdFeB sintered\nmagnet material has been developed. The magnets are produced by powder\nmetallurgy route involving hydrogen decrepitation technique for making\nfine powder. After melting and casting, the NdFeB alloy is subject to\nhydrogen atmosphere. Hydrogen slowly absorbs into the solid alloy and\nmakes it brittle, which upon milling becomes fine powder. Hydrogen is\nthen removed by placing the powder at temperature around 800 degrees C\nunder vacuum. Then the powders are pressed under isostatic conditions\nand sintered at temperature range of 1020-1050 degrees C. Post\nsintering is done at 800 degrees C and 580 degrees C followed by\nquenching. Energy product in the range of 8 MGOe is achieved.