Product Code: ICA11_N304

Fiber Laser Processing of Amorphous Rare Earth NeFeB Magnetic Materials
Authors:
David Hopkinson, The University of Cambridge; Cambridge Great Britain
Andrew Cockburn, The University of Cambridge; Cambridge Great Britain
William O\'Neill, The University of Cambridge; Cambridge Great Britain
Presented at ICALEO 2011

Since the exchange coupling theory was proposed by Kneller and Hawig in 1991 there has been a significant effort within the magnetic materials community to enhance the performance of rare earth magnets by utilising nanocomposite metamaterials. Inclusions of magnetically soft iron smaller than approximately 10 nm in diameter are exchange coupled to a surrounding magnetically hard Nd2Fe14B matrix and provide an enhanced saturisation magnetisation without reducing coercivity. For such a fine nanostructure to be produced, close control over the thermal history of the material is needed. A processing route which provides this is laser annealing from an amorphous alloy precursor. In the current work, relationships between laser parameters, thermal histories of laser processed amorphous NdFeB ribbons and the grain sizes in the resulting nanocrystalline products have been determined.