A kind of method for preparing permanent-magnetic material of Sm-Fe-C compound
The present invention relates to a kind of method for preparing rare-earth transition metal carbide permanent magnet material.
Although the Nd-Fe-B permanent magnet has good magnetic performance such as high saturated magnetic energy product, the weakness that its Curie temperature is low has limited the range of application of this material.The clear 62-170455 of patent JP of for example relevant Nd-Fe-B, the clear 62-151541 of JP, the clear 62-152108 of JP, the clear 62-149108 of JP, the clear 62-151542 of JP, the clear 62-158854 of JP, the clear 62-156248 of JP, the clear 62-124702 of JP, the clear 62-177149 of JP, the clear 62-174905 of JP etc.In recent years, the progress of exploring the novel permanent magnetic material in the world wide is rapid, but relevant work mainly concentrates on 2: 17,2: 14: 1 type ternary compounds, wherein the new way of exploring novel cpd has been opened up in the discovery of Sm-Fe-C (N) type compound, discover that carbon enters Curie temperature and the magnetocrystalline anisotropy that 2: 17 lattices can greatly improve compound as interstitial atom, owing to contain carboritride at pyrolytic decomposition, and special nitriding carbon process limited the application of Sm-Fe-C, and the research work of this respect remains a new breakthrough.
The object of the present invention is to provide a kind of method for preparing permanent-magnetic material of Sm-Fe-C compound, this method technology is simple, and the prepared Sm that goes out
2Fe
17C has good intrinsic magnetic properties and higher thermostability.
The invention provides a kind of method for preparing permanent-magnetic material of Sm-Fe-C compound, related permanent magnet material is Sm
y(FeCoTi)
100-1.5yC
0.5y, 8≤y≤20 wherein; The primary process of its preparation is that pure rare earth, pure iron, pure transition metal, graphite are prepared burden by the compound composition; mode with ball milling is carried out mechanical alloying; 3~20 hours ball milling time; thermal treatment is 0.1~10 hour under 650~950 ℃ of vacuum conditions; it is characterized in that: adopting above-mentioned mechanical alloying method to make powder diameter is 1~3 micron; it is carried out after the above-mentioned thermal treatment ball milling 0.3~4 hour under argon shield again, 300~650 ℃ of vacuum heat treatment 0.3~30 hour.
Because Sm
2Fe
14The direction of magnetization of C is easy face, Sm
2Fe
17Direction of magnetization also be easy face, when adopting common preparation method to prepare Sm
yFe
100-1.5yC
0.5y, during (8≤y≤20) alloy, formation be 2: 14: 1 phase Sm
2Fe
14C and Sm
2Fe
17, and the few Sm of content
2Fe
17So C is the permanent magnetism performance that alloy does not have.The reason that causes this consequence is that annealing temperature is too high among the common preparation method, studies show that, carbon just might enter 2: 17 interstitial sites in mutually and form the Sm with magnetic easy axis direction only when being lower than 650 ℃
2Fe
17C
x(0≤x≤3), this has just formed contradiction, and annealing temperature is crossed the low crystallization that is unfavorable for alloy again, can not prepare the alloy with good permanent magnetism performance equally.Method provided by the invention is by twice ball milling, and twice annealed technology has solved an above-mentioned difficult problem well.In a word, the present invention has overcome the weakness of carburization process, directly prepares the rare-earth transition metal carbide by the mechanical alloying method, and Zhi Bei rare-earth transition metal carbide not only has good intrinsic magnetic properties in this way, and has higher thermostability.
Below by embodiment in detail the present invention is described in detail.
Embodiment 1
Press standard component Sm with the powder of pure samarium, pure iron and graphite
14Fe
79C
7(atomic percent) batching is placed in the ball grinder, ratio of grinding media to material 23: 1, and 12 millimeters of spherical diameter, rotating speed 15 meter per seconds, 54 millimeters of jar diameters, 100 millimeters of jar rotating diameters, ball milling be after 5 hours, 1~3 micron of particle diameter; 800 ℃ of vacuum annealings, placed ball grinder again in 30 minutes, ground 1 hour, 550 ℃ of vacuum annealings 30 minutes, get final product to such an extent that principal phase is Sm
2Fe
17The permanent-magnet powder of C, its permanent magnetism performance is (BH)
Max=87.5KJ/m
3(11MGOe), M
e=11.8kGs, M
r=9.35kGs.
iH
c=215kA/m (2.7kOe) can prepare magnet by the powder bonded method, without secondary ball milling and annealed Sm
14Fe
79C
7Maximum magnetic energy product (BH)
Max=0.01MGOe, HCJ
iH
c=0.17kOe, (annealing 35 minutes for 800 ℃).
Embodiment 2
Powder with pure samarium, pure iron, pure titanium and graphite is pressed standard component Sm
14Fe
77Ti
2C
7(atomic percent) batching is placed in the ball grinder, grinds 5 hours, 850 ℃ of vacuum annealings, places ball grinder again in 30 minutes, grinds 1 hour, 600 ℃ of vacuum annealings 30 minutes, gets final product to such an extent that principal phase is Sm
2(Fe
17-zTi
z) C
xPermanent-magnet powder, its permanent magnetism performance is (BH)
Max=65.0kJ/m
3(8.17MGOe), M
e=1.02T, M
r=0.81T,
iH
c=207kA/m (2.60kOe) can prepare magnet by the powder bonded method.
Embodiment 3
Powder with pure samarium, pure iron, pure cobalt and graphite is pressed standard component Sm
14Fe
75Co
4C
7(atomic percent) batching is placed in the ball grinder, grinds 5 hours, 850 ℃ of vacuum annealings, places ball grinder again in 30 minutes, grinds 1 hour, 600 ℃ of vacuum annealings 30 minutes, gets final product to such an extent that principal phase is Sm
2(Fe
17-uCo
u) permanent-magnet powder of Cx, its permanent magnetism performance is (BH)
Max=51.6kJ/m
3(6.48MGOe) .M
e=1.14T, M
r=0.86T,
iH
c=135.3kA/m (1.70kOe) can prepare magnet by the powder bonded method.