Nd-Fe-B magnetic materials yield many different compounds in solidification process. For this reason, conventional mold-casting method used for Sm-Co magnetic materials was not suitable for quality and productivity. To solve their problem, rapid solidification was required. To rapidly solidify the alloy melt, thin mold gap in conventional mold-casting method was tried, but it was not suitable for productivity. New production method was developed; it was mold-free and able to rapidly and uniformly solidify the alloy melt. It was devised as the method between continuous casting and single roll casting based on melt-spinning. Several conditions were tried and followed effects were acquired. Milling and sintering were improved due to microscopic and uniform constitutions. We call the method as "Strip-casting method".
In this paper, constitution characteristics of alloys produced by Strip-casting and conventional mold-casting method, and the influence for production of magnet using those alloys are summarized. Transition of production and development for other products are also reported.