Pr/Nd based biphase composite permanent magnetic material and block body preparing method thereof

Abstract

The invention relates to a Pr / Nd-based two-phase nano-composite permanent magnet material and a method for the preparation of the block body thereof. The invention comprises the composing general formula of the two-phase nano-composite permanent magnet material: a (Pr, Nd)-Fe-R-Ti-QB system, wherein Pr and Nd are main rare earth components in hard magnetic phase (Pr, Nd)2Fe14B base material; R is one or more than two of Nb, Dy, Tb and Ga; Q is one or more than two of V, Mo, Zr, W and Au; the molar fraction is as follows: x is more than or equal to 4 and less than or equal to 11, y is more than or equal to 0.1 and less than or equal to 3, z is more than or equal to 0.1 and less than or equal to 4, m is more than or equal to 0 and less than or equal to 2, n is more than or equal to 6 and less than or equal to 10, w is more than or equal to 20 and less than or equal to 80, and the balance being Fe. The preparation of the block body (Pr, Nd) 2Fe14B / Alpha-Fe comprises the following steps of (1) smelting master alloy; (2) fast quenching of thin strips; (3) preparing the block body by ultra-high heat pressing, in which the thin strip alloy is put in a graphite mold and then is placed in an ultra-high pressure device, and is sintered for 1 to 30min when the temperature is heated to between 500 and 1000 DEG C at 10-50 DEG C / min, under the pressure intensity of between 1 and 12 GPa and Ar gas protective environment. The Pr / Nd-based two-phase nano-composite permanent magnet material has the advantages of low-content rare earth, low cost, good anti-saturation effect, and the like; the magnetic energy is more than 180 kJ / m3, and the density is more than 74.5 g / cm3.

Description

technical field [0001] The invention relates to a magnetic functional material, in particular to a dual-phase nanocomposite permanent magnet material with low cost and good corrosion resistance and a preparation method thereof. Background technique [0002] Nano-composite permanent magnet alloys utilize the advantages of high magnetic crystal anisotropy of the hard magnetic phase and high saturation magnetization of the soft magnetic phase, and obtain excellent magnetic properties through the ferromagnetic exchange coupling between the two-phase grains at the nanoscale , the theoretical magnetic energy product can be as high as 10 6 J / m 3 , known as the "megajoule permanent magnet". Due to its low rare earth content, low price and good corrosion resistance, it is expected to develop into a new generation of high-performance permanent magnet materials. At present, the hard magnetic phase in nanocrystalline composite permanent magnet materials is mainly Nd 2 Fe 14 B or Sm...

AI Technical Summary

Problems solved by technology

[0008] The present invention aims at the bulk Nd produced by crystallization annealing and bonding method after direct rapid quenching of the melt 2 Fe 14 In the B / α-Fe nano-two-phase permanent magnet material, the problem of low magnetic performance due to the deficiency of the preparation process is to provide a Pr / Nd-based two-phase nano-composite permanent magnet with low rare earth content, low cost, and good corrosion resistance. Magnetic material formula and method for preparing high-density block by ultra-high pressure

This method effectively solves the problems of large grain size deviation between soft and hard magnetic phases, insufficient contact between soft and hard magnetic phases leading to decoupling, and low density due to doping with organic binders. The bulk sample is close to the ideal exchange coupling model requirements of soft and hard magnetic phases, thus greatly improving the magnetic properties of this type of material, and providing a new way to realize the preparation of nanocomposite magnets with ideal microstructure

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