JPS58167760A - Preparation of manganese-aluminum alloy magnet - Google Patents

Abstract

PURPOSE:To obtain a ribbon shaped Mn-Al alloy magnet excellent in magnetic characteristics, by a method wherein the melt of an alloy having Mn and Al compounded therein within a specific range is molded into a ribbon shape by superquenching and the formed ribbon shaped object is annealed in a magnetic field within a proper temp. range. CONSTITUTION:The melt of an alloy comprising 65.3-67.3wt% Mn and 34.7- 32.7wt% Al is blown onto a steel rotary roll to be molded into a ribbon shape by super-quenching. This ribbon shaped material is annealed at 540-680 deg.C in a magnetic field within a heating furnace. By this method, a Mn-Al alloy magnet with BHmax of 0.8MG.Oe is obtained without adding other alloy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing permanent magnet materials, and more particularly to manganese-alunium (MnAt) alloy magnets.

Since MnAt compounds have a high magnetic anisotropy constant, they are expected to be used as permanent magnet materials and are being researched and developed. MnAt alloy subjected to appropriate heat treatment (quenching and tempering)
The magnetic property of nAt alloy magnet is 0.5M in BHmix.
G・0・, 2200G during BT.

It was about H.Kilo 000＠. Therefore, the rod-shaped Mm
Enclose an Aj alloy magnet in a metal magnet (non-magnetic stainless steel), etc., and apply swaging as it is to create an anisotropic permanent magnet of about 3.5 MG@O@ It is known that

However, due to the swaging process, the MnAt alloy is pulverized into a powder inside the metal mold, and the product shape is limited to a thin rod coated with a mother plate, and the manufacturing cost is extremely high. . M is made by adding cinnabar (C) to the alloy to improve magnetic properties and workability.
An m-mu t-C alloy magnet has been proposed (see, for example, Japanese Patent Publication No. 31448/1983), and this Mn-mu t-
The C-based alloy magnet has a composition of 68.0 to 73. Ovt.
Mn and 1 (to MB -6-6) ~ (s Mm
2 2.2) C of wtlG and remaining A
It consists of 530-830m? The material is subjected to warm plastic working at , and has a structure in which the (001) axis of the face-centered tetragonal crystal is preferentially aligned in a specific direction. And BHm□ is 4.
An anisotropic Mm-mt-C alloy magnet of 8 MG@O. or more can be obtained. However, the product shape is limited to rounding by warm extrusion molding.

The object of the present invention is to obtain an R4At @full magnet with a BHmhx of 0.8 MG·0· or more by changing the manufacturing process without adding alloys.

The purpose of the present invention is to produce a remen-shaped MnA1 alloy magnet.

The above purpose was to ultra-quench an alloy melt of 65.3 to 67.3 wt of Mt and 34.7 to 32.7 vtl of At, form it into a ring shape, and then heat it in a magnetic field at 540 to 680°C. MnAj consisting of medium annealing 4! This is achieved by a method for manufacturing r gold magnets.

Preferably, super-quenching is carried out by spraying the alloy melt onto rolls rotating at high speed.

M in MA1 alloy! If the amount is outside the range of 65.3 to 67.3 wt1, the maximum energy product "max" will be smaller than α8MG.Oe as a permanent magnet on the flank of a general rubber magnet.

Roughly speaking, if the annealing temperature is outside flQ'8 of 540 to 680°C, B%aK of the MnAt alloy magnet is 0.8 MG+
It becomes smaller than 10*.

The present invention will be explained below with reference to embodiment examples of the method of the present invention.

Various What alloys with varying Mn content between 65 wt and 75 vtl were prepared in an MIA4 alloy #alloy tube melting furnace (eg, high frequency furnace). This melt (1
Steel roll (diameter: 220cm, roll rotation speed: 40cm) rotating from a 100°C)'ft nozzle diameter: 1m)
00rpm) K spray (injection pressure crab 0.5k)/♂
), ultra-quenched or formed into a linear sample. ? 4? The resin-shaped sample had a diameter of about 2 cm and a thickness of 20 to 40 mm, and was annealed in a magnetic field at various temperatures in a heating furnace for 1 hour. In this annealing, the heating and cooling rate was 100°C/h, and the magnetic field was 104°C/h.
was applied in the axial direction. -1 was added to the magnetic properties of the seven-dimensional sample during annealing at room temperature. MnA from the obtained observation koji
1 alloy magnet M stoichiometry and coercive force He, residual magnetic flux density g B
r, magnetic flux density at 15 kO*1. , ko* and the maximum energy product "IIaK" are shown in Figures 1 and 2.As is clear from the BH,,x graph in Figure 2, there are two The mountain is Toshi, and the mountain on the right on the drawing is the special public official court of 1977-314.
This corresponds to Mn Jil in the Mn-At-C alloy magnet proposed in Publication No. 48.

The present invention deals with MnA at the Mnj11 node, which corresponds to the mountain on the left.
It is a t-alloy magnet, and as shown in the H@ graph in FIG.

0.8 Judging from the BHmax of MG・O・, Mn
The Mn content of the A4 alloy magnet is 65.3 vtl to 67.
It is in the range of 3vNl. Furthermore, from the graph of "HT, aX" in FIG. 2, it can be seen that the annealing temperatures of the curves showing the peak on the left for the Mn amount related to unexploded #JK and the peak for right 11i+, which is not, are reversed. That is, the annealing temperature is reversed. , 66wt in the present invention
The BH peak for Mn was obtained at an annealing temperature of 600 °C,
On the other hand, the BH peak for 70 wt4 Mn was obtained at an annealing temperature of 400°C.

@3 Figure shows 6 6 wt4 Mn 34 according to the present invention.
Annealing temperature and coercive force Ha% residual magnetic flux density Br, magnetic flux density B1. kO・
and the relationship with the maximum energy product BH, □8.

In the BH graph of Figure 3, BHr of 0.8 MG・0・
, the annealing temperature range to achieve x is 540°C to 680°C.
It can be seen that the temperature is ℃.

Therefore, a permanent magnet can be manufactured by forming a molten MnAt alloy into an in-line shape using an ultra-quenching method, and then performing an appropriate annealing treatment.

[Brief explanation of drawings]

Figure 1 shows the MvskL alloy magnet OM weight and I (e and B
Figure 2 shows the relationship between the Mn content of the MnA1 alloy magnet and B, , ko・
and l1flrnax, and is a diagram showing the relationship between the third
The figure shows the relationship between the annealing temperature of a 66 wt9G Mm 34 vt excellent Al @all magnet and H., Bra B, sko., and BH Ya, □. Patent Applicant: Fujitsu Limited Patent Attorney: Akira Minori, Patent Attorney: Kazuyuki Nishidate, Patent Attorney: 1) Yukio, Patent Attorney: Akira Yamaguchi Figure 1 Mn (at'10) Figure 2 Mn (ai@ 10)

Claims (1)

[Claims] An alloy melt of 1-r gun 65.3 vtl ~ 67.3 wtl and aluminum 34.7 vt % ~ 32.7 vt- is ultra-quenched and formed into a 54-r gun shape.
A method for producing an aluminum alloy magnet comprising annealing in a magnetic field at 0°C to 680°C.