Hydrogen Decrepitation Press-Less Process recycling of NdFeB sintered magnets

A Hydrogen Decrepitation Press-Less Process (HD-PLP) recycling method for recycling of anisotropic NdFeB magnets is demonstrated. The method combines hydrogen decrepitation (HD) disintegration of the initial magnet, powder sieving and the Press-Less Process (PLP), where hydride powder is sintered in a graphite mold. Coercivities up to 534 kA/m were obtained in porous samples based on powder size d <  100 µm. Adding a ball milling step resulted in full density isotropic magnets for d >  100 µm. The coercivity reached Hci =  957 kA/m being 86% of the original N48M material without addition of rare earth elements.