Alloy flake for rare earth magnet, production method thereof, alloy powder for rare earth sintered magnet, rare earth sintered magnet, alloy powder for bonded magnet and bonded magnet

摘要

Disclosed is a rare earth magnet in the R—T—B (rare earth element-transition metal-boron) system that is made from an improved composition and properties of main phase alloy in the R—T—B system containing Pr and a boundary alloy. Disclosed also is a manufacturing method of the rare earth magnet alloy flake by a strip casting method with improved rotating rollers such that the alloy flake has a specified fine surface roughness and has a small and regulated amount of fine R-rich phase regions. Consequently, the alloy flake for the rare earth magnet does not containing α-Fe and has a homogeneous morphology so that the rare earth magnet formed by sintering or bonding the alloy flakes exhibits excellent magnetic properties.