Boron-free hard magnetic comprising a magnetic tetragonal phase

摘要

A boron-free hard magnetic material on the basis of neodymium, iron and carbon which comprises a hard magnetic, finely crystalline tetragonal phase having a grain size equal to or smaller than 0.2 µm, and which has the Nd₂Fe₁₄C structure. The material can be obtained by spraying a molten alloy onto a rapidly moving chill surface, while forming flakes having a thickness of 30 µm or less. The material thus obtained is subsequently annealed at a temperature between 685 and 730°C, such that the desired structure is formed.