JPS58136757A - Manufacture of permanent magnet alloy - Google Patents

Abstract

PURPOSE:To obtain a permanent magnet alloy with enhanced magnetic characteristics by sintering an intermetallic compound alloy having a specified composition consisting of a rare earth metal and transition metals and by subjecting the sintered body to soln. heat treatment under specified conditions and aging. CONSTITUTION:An intermetallic compound alloy having a composition represented by the general formula (where R is one or more among Y, Ce, Pr, Nd, Sm and misch metal, M is one or more among Ti, Zr, Hf, Nb and Ta, 0.2<= alpha<=0.4, 0.3<=beta<=0.06, 0.005<=gamma<=0.05 and 7.5<=z<=8.4) is pulverized, molded and sintered. The sintered body is held at 1,100-1,200 deg.C for >=1hr and rapidly cooled at once to <=900 deg.C at >=1 deg.C/sec cooling rate to form Th2Ni17 type single phase crystals by soln. heat treatment, and aging is carried out. By this method a permanent magnet alloy with superior coercive force and high performance can be manufactured stably.

Description

[Detailed Description of the Invention] The present invention focuses on rare earth metals R (wherein R consists of one or more of Y, Ce, Pr, Nd, Sn+, M, and M), Go, and Fe. The present invention relates to a method for producing a permanent magnet alloy mainly containing an R2'rTi type compound among intermetallic compounds with a transition metal (T). Among permanent magnet alloys mainly composed of R2T type compounds, RT
In the T-type composition, the cage energy product (B H) tnax
"t 30MGOe, residual magnetic flux density Br &IIKG
Permanent magnetic alloys that reach up to However, since the above RT7 type composition magnet has only about 6 KOe per tlc, the demagnetization curve includes a break point, so it cannot be used for applications with a small permeance coefficient. It was only applied to devices that mainly utilized the generated magnetic field, and the original high energy product could not be fully utilized. In Japanese Patent Application No. 56-120841, the present inventors disclosed that the IIT・? New R2 that improves the shortcomings of molded bottom magnets
Although the Tr1 type permanent magnet alloy was invented, subsequent research showed that the solution treatment time was carried out for a long time, and the alloy crystal structure was completely transformed into a high-temperature stable phase, Th2 Nii? By converting the hexagonal hexagonal crystal into a single phase, rapidly cooling the state to room temperature (below 900 degrees Celsius), and transferring it to the next aging process while it is stored, it has high coercive force and good magnetic properties with squareness. It was found that it was possible to obtain The crystal 1J' state is finally transformed into 1'b 27. by the aging treatment in the next step. Although it has an n+7 type trigonal rhombohedral structure, it becomes a uniform Th2Ni17 type hexagonal structure at the end of solution treatment, which leads to uniform precipitation at the aging stage and increases coercivity. Although the effect of the present invention was hardly seen with the conventional RT7 type magnet,
-a-s-rFe, Cus M/ ) z in the general formula 0.2≦7≦0.4゜0.03≦β≦0.06.0.
Remarkable improvements in magnetic properties were obtained for alloys with compositions of 005≦, ≦0.05, and 7.5≦2≦8.4. (However, R is Y, Ce, Pr, Nd. Sm, M, M, combination (, M is Ti, Zr, IIf, N
It consists of a combination of b and Ta. ) The features and effects of the present invention will be described in detail below with reference to Examples. Example, Y[), 25m0.8 (f: oO, 650
1'eO, 285Cu1), 045ZrO, 020)
An alloy represented by the general formula 7.85 was melted in an induction heating furnace to obtain an ingot in a water-cooled mold. The ingot was made into fine powder with an average particle size of 4 μm by a vibration mill method. Next, the fine powder is 51/c+++ without applying a magnetic field of about 20 KOe.
A raw material was obtained by compression molding using a mold at a pressure of . After evacuating the raw material for a long enough time (approximately 10 hours) to completely exhaust any gases such as air remaining inside, it is heated to approximately to” Torr.
1200℃ in vacuum. After sintering for 2 hours, a sample for solution treatment experiment was prepared. Five types of solution treatment were performed under the conditions shown in Table 1 (solution temperature 1170°
C) experimented. The crystal structure was investigated by X-ray diffraction using a powder method after solution treatment, and the diffraction lines shown in FIG. 1 were obtained. Figure 1 fil, +21. +31 is the solution temperature and the solution time at 170°C is 0.5. 1. 1
The X-ray diffraction pattern for 2 hours is shown. Samples prepared under each condition were then heated to 900°C. After heating for 3 hours, the mixture was slowly cooled to room temperature at a cooling rate of 1° C./sec. When the magnetic properties of the obtained sintered body were measured, it showed demagnetization properties, which are not shown in FIG. Figure 2 (41, +51.
(6+, +71. (81 is sample No.,
1. 2゜3,. 4.5 demagnetization curve is shown. Table 1 Comparison of Figures 1 and 2 shows that the crystal structure after the solution treatment is much more Th2Niil hexagonal than in Figure 1, but as the solution treatment time increases -1゛( , the peak becomes a sharp diffraction pattern and the crystal structure transitions to a complete state. This change corresponds to an increase in coercive force and a direction in squareness in Figure 2. In other words, an increase in solution time causes magnetic It is clear that this is a factor that significantly improves the properties.The effect can be seen after processing for more than 1 hour.As detailed above, the method for producing a permanent magnet alloy according to the present invention has a high performance. The present invention provides a solution treatment method for stably manufacturing R2T1? magnets.

[Brief explanation of the drawing]

Figure 1 shows the X-ray diffraction pattern of a permanent magnet alloy. FIG. 2 shows a demagnetization curve of a permanent magnet alloy, where the horizontal axis represents magnetic field strength (kilo-Oersted) and the vertical axis represents magnetization (kilo-Gauss). Patent applicant Namiki Precision Jewel Co., Ltd.

Claims (1)

[Claims] RCCo+-n-s-rFea, cusMr>z-
General formula (where R is Y, Ce, Pr, Nd, Sm, M,
One or more of M, M is Ti, Zr, lI
It consists of one or more of t', Nb, and Ta. )in. , #2. ．． The range of z is 0.2≦0≦0. 4. 03≦β≦0.06 (1,005≦, ≦0.05 7.5≦2≦8.4) Grinding, forming, sintering, and solution treatment 1
In the manufacturing method of magnetizing from each step of aging, the solution treatment is held at a temperature range of 1100°C to 1200°C for at least 1 hour, and immediately heated to 900°C or less at 1'C/s
A method for producing a permanent magnet alloy, characterized in that it is rapidly cooled at a cooling rate of ec or more to form a Th2 Ni17 type single phase crystal, and then aged.