JPS5818423B2 - semi-hard magnetic alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an alloy containing Fe, Mn and Ti as main components (F e -M containing a composite of CO and Mo).
The present invention relates to an n-Ti semi-hard magnetic alloy.

Semi-hard magnets that have been commonly used include Fe.
, Co, and ■ Picaloy magnet, F
KS magnet whose main components are e, Co, and C, Fe, C
There are Cunifue magnets whose main components are u and Ni, and all of them have been put into practical use to some extent.

However, since these magnetic alloys contain large amounts of expensive alloying elements such as Co, Ni, or V, the material cost accounts for a large proportion of the manufacturing cost, making them extremely disadvantageous economically.

The alloy of the present invention was newly developed to eliminate the above drawbacks, and is the result of research aimed at improving the magnetic properties of an inexpensive Fe-Mn-Ti alloy and making it possible to put it into practical use. This is what was obtained.

□ The biggest use of semi-hard magnets is in the rotors of rotating machines called hysteresis motors, which are relatively small and have low output but have excellent rotational characteristics, and the magnets used in these motors are often ring-shaped.

Therefore, possible manufacturing methods include casting, hot forging, machining from a rolled material, hot extrusion, and press forming.

However, in general, forming a magnet material into a ring shape at room temperature is quite difficult because the plastic deformation resistance is large except for cutting out.

However, it is well known that conventional Fs-MnTi alloys require considerable strength processing at room temperature in order to maximize their properties. It is extremely difficult to use it as a rotor material for hysteresis motors.

Therefore, when improving Fe-Mn-Ti alloys, we tried to obtain materials that do not require cold rolling to obtain good magnetic properties, that is, to obtain the necessary magnetic properties only by casting or heat treatment of hot-worked materials. Recently, research has been conducted on Fe-'Mn-Ti alloys other than the alloys of the present invention.
There are also a few alloys containing small amounts of u, etc.

Currently, the magnetic properties required for hysteresis smoke are generally coercive force (Hc) of about 50 to 1800 s,
The residual magnetic flux density is 7500G or more, and the quantity is 14
Most of the materials require a coercive force of about 0 to 1800e, whereas the above-mentioned Si.

Fe-Mn- whose magnetic properties have been improved by adding Cu, etc.
Ti-based alloys often have a maximum coercive force of about 1400e, and therefore cannot currently meet all the demands of hysteresis motors.

The alloy of the present invention was invented for the purpose of scaling semi-hard magnetic materials with a coercive force of 140 to 1800e, and is Fe-M
By simultaneously containing Co and Mo as new additive elements in the n-Ti alloy (thus, it can exhibit various excellent magnetic properties, and in addition to the hysteresis motor, it can also be used in automobile meters, hysteresis brakes,
It can be expected to have a wide range of applications such as hysteresis launch.

The alloy of the present invention improves the residual magnetic flux density when an Fe alloy containing a weight ratio of M n I Q ~ 14 and Ti 1.5 ~ 4 is subjected to aging treatment to increase the residual magnetic flux density and increase the coercive force. In order to prevent the decrease, 1 to 10 Co is added, and in order to further increase the coercive force, Mo or 0.
After this alloy is obtained by ordinary melting methods such as air, atmosphere, or vacuum melting, it is formed by casting [forming by molding or by applying appropriate force processing at high temperatures]. After that, excellent magnetic properties are obtained by aging treatment at a temperature of 400 to 600°C.

Furthermore, prior to aging, the magnetic properties can be further improved by performing solution treatment such as cooling in air from a temperature of 950 to 1200°C or rapid HF in water.

The range of components of the alloy of the present invention is limited as follows.

Mn is one of the basic elements forming the alloy of the present invention, and its composition range must be determined quite strictly.

If the Mn value is lower than 10%, it is difficult to obtain the necessary coercive force, and if the Mn value exceeds 14, a large amount of non-magnetic γ phase will remain at room temperature, and as a result, the coercive force will increase, but The residual magnetic flux density decreases rapidly.

Therefore, the composition range of Mn is set to be 10 to 14.

Ti is also one of the main components, and cold rolling can be made unnecessary by adding Ti, so it is particularly important as a rotor material for hysteresis motors.

This effect is exhibited when the Ti content is 1 or more, but
In particular, 1.5% or more of iron is required to improve magnetic properties.

Moreover, when Ti exceeds the 4th factor, the value of saturation magnetization decreases,
As a result, the residual magnetic flux density also decreases, making it impossible to expect good magnetic properties.

Therefore, the optimum component range for Ti is 1.5 to 4.

Co is a characteristic feature of the alloy of the present invention, and by including Co, an increase in residual magnetic flux density, which was insufficient with Ti alone, can be achieved.

Increasing the coercive force can be achieved simply by increasing the amount of Mn or increasing the aging temperature, but in this case,
It is not possible to prevent a large drop in residual magnetic flux density.

By including Co, it is possible to prevent a decrease in the residual magnetic flux density caused by an increase in coercive force, and it is also possible to increase the residual magnetic flux density as a whole.

This is a new fact that has not been considered at all in the past.

This effect varies depending on the amount of Co added, but if it is less than 1%, this effect is not noticeable, and if it exceeds a factor of 10, the rate of increase in residual magnetic flux density is Since it is small and disadvantageous in terms of material cost, the range of Co is 1 to 10.

'Mo has particularly good results when added in combination with CO, and it makes no sense to add it alone to the Fe-Mn Ti alloy.

That is, the meaning of Mo inclusion is that when Mo is added to the Fe-Mn-Ti-Co system, the coercive force is increased without significantly reducing the residual magnetic flux density.

This content is limited to the 5th factor, and if the amount of Mo is increased beyond this, the residual magnetic flux density will drop sharply.

Further, if the content is less than 0.5%, the coercive force cannot be increased.

Therefore, the content of Mo is set to 0.5 to 5.

□ In addition to the above components, Si and AI are elements that are mixed during melting or added in trace amounts as deoxidizing agents.

There are Mg+CyCa+Cu, etc., but these impurity elements do not exhibit much harmful effects as long as the total amount does not exceed 1 part.

However, it is desirable that the content of either AI or Si used as a deoxidizer does not exceed 0.5%.

Further, C tends to chemically combine with Ti and reduce the effect of Ti.

It is desirable to suppress it to 0.05% or less.

Next, examples of the alloy of the present invention will be shown.

1 Example 1 Melting in vacuum (13.1% Mn thus obtained, 2.88%
After hot working an iron alloy containing Ti, 4.9% Co and 1.89% MO at 1,15.0°C, it was
The magnetic properties of the material aged at 50°C were a residual magnetic flux density of 8,200G and a coercive force of 1,520e.

The same material aged at 550° C. for 2 hours showed a residual magnetic flux density of 7.700 G and a coercive force of 1,680 e.

Example 2 1 obtained by dissolution in air 1. , 5%M n, 3.
When an iron alloy containing 67% Ti, 7.8% Co and 4.15% Mo was aged at 500°C for 30 hours after hot working, the residual magnetic flux density was 7,600B and the coercive force was 160.
The magnetic properties of Ce were obtained.

Example 3 1 3.6% M n, 2.7 obtained by dissolution in vacuum
When an iron alloy containing 5% Ti and 4.98% Co was hot-worked and then aged at 500°C for 20 hours, magnetic properties with a residual magnetic flux density of 8,300G and a coercive force of 1320e were obtained.

On the other hand, 13.5% Mn obtained by melting in vacuum, 2.7 s
After hot working an iron alloy containing %sri, so%co, and 0.5%Mo at 1,150°C,
When this was aged at 500° C. for 20 hours, magnetic properties with a residual magnetic flux density of 8,300 G and a coercive force of 1400 e were obtained.

Example 4 10.8% M n obtained by dissolution in air, 3.8
When an iron alloy containing 5%'ri, 9.2% CO11, and 0% MO was hot-worked and then aged at 500°C for 10 hours, magnetic properties of 9.0OOG and coercive force of 1550e were obtained.

In order to explain the effects of the present alloy in more detail, the results of comparison with a conventional Fe-Mn-Ti alloy are shown in the figure.

Curve A in the figure is a correlation diagram showing the relationship between residual magnetic flux density and coercive force obtained by performing various heat treatments on a conventional alloy consisting of 13.5% Mn, 3.10 Ti, and the balance Fe. Curve B is a correlation diagram showing the relationship between residual magnetic flux density and coercive force obtained by performing various heat treatments. 13.3% Mn, 2.61% Ti, 3 of the invention alloy
．． A correlation diagram of total gold consisting of 8% Co, 3.5% Mo, 0.28L:fbSi, and the balance Fe is shown, respectively.

From this figure, Co and Mo in the Fe-Mn-Ti alloy
It can be seen that the effect of containing the composite addition of is extremely large.

Since this alloy is a precipitation type alloy that utilizes the precipitation of Ti, it requires aging treatment, and if aging is not performed, it will not be able to maintain its excellent magnetic properties.

As described above, the alloy of the present invention is industrially easy to manufacture, and the forming methods include the above-mentioned hot processing,
This alloy can be manufactured by any method such as hot pressing, hot extrusion, etc., and this alloy can also be cold worked to some extent before aging, and cold working improves its magnetic properties to a certain extent. It is also known to improve

[Brief explanation of the drawing]

The figure is a diagram showing a comparison between the alloy of the present invention and a conventional Fe-Mn-Ti alloy.

Claims (1)

[Claims] 1 Mn 10-14'%, Ti 1.5-4% by weight,
A semi-hard magnetic alloy characterized by containing 1 to 10% of Co, 0.5 to 5% of Mo, and impurity elements mixed in from the manufacturing process in a total amount of 1 coefficient or less, and the balance being Fe.