Praseodymium-Ferrum-Boron permanent magnet and preparation method thereof

Abstract

The invention provides a Praseodymium-Ferrum-Boron permanent magnet and a preparation method of the Praseodymium-Ferrum-Boron permanent magnet. The permanent magnet is made from an alloy with a mass percent represented by Pr<30.3+a+b>Fe<67.16-x-y-z>Cu<x>Nb<y>Al<z>B<1.04>, wherein a+b represents the lost mass percent of praseodymium in oxidization and melting processes; a+b is not larger than 1.5, x is not smaller than 0.15 and not larger than 0.20, y is not smaller than 0.14 and not larger than 0.5, and z is not smaller than 0.4 and not larger than 0.55. The Praseodymium-Ferrum-Boron permanent magnet can achieve high Br and high Hci simultaneously at normal temperature and is excellent in magnetic performance, low in preparation cost, and good in magnetic field stability, magnetic field homogeneity and plating airtightness; the Praseodymium-Ferrum-Boron permanent magnet can realize practical application in the engineering of high-precision low-temperature permanent magnet devices such as cryogenic permanent magnet undulators (CPMU) as well as in the fields of space instruments and meters.

Description

technical field [0001] The invention relates to a PrFeB permanent magnet and a preparation method thereof. The PrFeB permanent magnet prepared by the method can be used in various high-precision low-temperature permanent magnet devices such as low-temperature undulator (CPMU) inserts of synchrotron radiation sources, etc. It can also be used in fields such as space instrumentation. Background technique [0002] After nearly 30 years of research and development of sintered neodymium iron boron (NdFeB) permanent magnets, the remanence Br of commercial NdFeB at room temperature has reached 1.5T, which is close to 93.8% of the theoretical value, and there is little room for further improvement; the intrinsic coercivity The force Hci has also been greatly improved, and the highest has reached more than 3000KA / m, which is close to 53.5% of the theoretical value. In addition, NdFeB exhibits spin reorientation (SRT) at 130-150K, which limits the further improvement and application ...

AI Technical Summary

Problems solved by technology

Generally, the coating used for ordinary sintered NdFeB or PrFeB is Ni / Cu / Ni coating. The disadvantage is that it has the effect of increasing the corner size, which makes the dimensional accuracy poor and the vacuum tightness poor.

Images