JPH01184907A - Manufacture of fe-ni magnetic alloy thin plate - Google Patents

Abstract

PURPOSE:To obtain the material having an excellent DC magnetic characteristics and a small high frequency loss by a method wherein, after an Fe-Ni alloy has been cold rolled into a specific plate thickness, a magnetic annealing is conducted thereon, the coldrolled material is maintained at the specific state in a nitrogen or nitrogen-hydrogen atmosphere, and an annealing treatment is conducted thereon. CONSTITUTION:After an Fe-Ni alloy (permalloy) has been fused, it is founded into an ingot, and after it has been forged and hot rolled, an acid pickling operation is conducted, cold rolling and annealing operations are conducted, and said material is rolled into the desired thickness and size of a plate. The target plate thickness of the above-mentioned cold rolling is to be 100mum or less. After a magnetic annealing work has been conducted on the abovementioned plate in the non-oxidizing atmosphere such as dried hydrogen and the like, for example, at 1000 deg.C or above for 10 minutes or more, the plate is cooled to the room temperature at a suitable cooling speed. Then, the plate is maintained in a nitrogen or nitrogen- hydrogen atmosphere at 500 deg.C or above for five minutes, and it is cooled to the room temperature at a suitable cooling speed. As a result, a nitride is generated on the surface of the material, the hardness of the surface of the material is increased, and a suitable hardness is given to the thin plate. Also, the effective thickness as a magnetic material is made thin, and DC magnetic characteristics can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a method for producing a high frequency nickel (Fe-Ni) based magnetic alloy thin plate particularly suitable for use under a high frequency magnetic field.

[Technical background and problems of the invention]

Permalloy is a typical magnetic alloy of Fe-Ni alloys. Permalloy is A grade (70-80% Ni, balance Fe)
), B class (40-50% Ni, remainder Fe), C class (
70-80% N1 and special components, balance Fe),
D class (35~40% Ni, balance Fe), E class (45~40% Ni, balance Fe)
There are various types such as 55% Ni, balance Fe), and these are used in relays, magnetic pole pieces, transformers, transformers, etc. depending on their characteristics.

Since permalloy as described above has a regular lattice transformation, its magnetism changes very sensitively by heat treatment. Among such Fe-Ni based magnetic materials, the magnetic material used under a high frequency magnetic field is required to have high effective magnetic permeability and low core loss. In particular, recent electronic devices are strongly required to be smaller in size, higher in performance, and higher in reliability, and one possible solution to these demands is to increase the frequency of magnetic materials used in inductors and transformers.

Recently, research and development has been carried out on amorphous metals manufactured by the molten metal quenching method. There are problems with the

For this reason, rolled magnetic thin plates have traditionally been used as magnetic cores used in high-frequency magnetic fields.
In order to reduce the eddy current loss of this magnetic thin plate, measures have been taken to reduce the thickness of the magnetic thin plate as much as possible. However, the thinner the plate is, the more it is affected by distortion that occurs when it is assembled into parts, causing problems such as the tendency for magnetic properties to deteriorate.

[Structure of the invention]

The present inventors have arrived at the present invention in view of this point. That is, in the present invention, Fe-Ni alloy is
After cold rolling to a thickness of 00 μm or less, magnetic annealing is performed, and then annealing treatment is performed in which the sheet is held at a temperature of 500° C. or more for 5 minutes or more in a nitrogen, nitrogen, or hydrogen atmosphere.
A method for manufacturing an e-Ni magnetic alloy thin plate is provided.

[Detailed description of the invention]

Next, the reasons for limiting the conditions in the present invention will be described in detail below.

In the present invention, first, the material Fe-Ni alloy (
Permalloy) is melted and cast into an ingot, which is then forged, hot rolled, pickled, and then cold rolled and annealed as necessary to form the required thickness. To go. The target plate thickness in this cold rolling is 100 μm or less. After this, magnetic annealing is performed. In magnetic annealing, the material is held at a temperature of 1000'C or more for 10 minutes or more in a non-oxidizing atmosphere such as dry hydrogen, and then cooled to room temperature at an appropriate cooling rate. Next, it is held at a temperature of 500° C. or higher for 5 minutes in a nitrogen, nitrogen, or hydrogen atmosphere, and then cooled to room temperature at an appropriate cooling rate. As a result, nitrides are formed on the surface of the material, increasing the hardness of the material surface and giving the thin plate appropriate strength. Furthermore, the effective thickness of the magnetic material becomes thinner, resulting in improved AC magnetic properties. This heat treatment can be performed at the same temperature as the magnetic annealing, if necessary, and can also serve as complementary magnetic annealing. By performing the above heat treatment, it is possible to obtain an ultrathin sheet (foil) of Fe-Ni alloy (permalloy) that has low AC loss, is not easily affected by distortion, and has high wear resistance when used as a magnetic head. Can be done. In this way, an ultra-thin sheet (foil) magnetic material with significantly improved AC magnetic properties can be produced.

The Fe-Ni alloy of the present invention includes permalloy as described above, but in order to improve magnetic properties, corrosion resistance, and wear resistance, alloy components (for example, Cr, Mo, W, C
o, Ca, Mn, Cu, V.

Nb, Ta, Ti, A1. Si, Mg, rare earth elements, etc.)
Of course, alloys containing 10% or less of the above Fe-Ni
It is included in the alloys.

In addition, in the present invention, what is described as a thin plate or an extremely thin plate includes foil, and the plate thickness also means the thickness of the foil. This is obvious from the description that the plate thickness is 100 μm or less.

〔Effect of the invention〕

The present invention makes it possible to obtain a material with excellent DC magnetic properties and low high-frequency loss, which cannot be obtained through the normal manufacturing process of magnetically annealing cold-rolled material as it is. It can make a significant contribution to the improvement of optimization and performance.

〔Example〕

Next, examples of the present invention will be described.

Fe-Ni plate thickness reduced to 100 μm or less by cold rolling
After magnetic annealing is applied to permalloy alloy.

It was kept at temperatures of 500°C, 900°C, and 1100°C for 15 minutes or more in an atmosphere of 100% nitrogen or 75% nitrogen and 25% hydrogen, and then cooled in a furnace. The magnetic annealing conditions were heating at 1100° C. for 1 hour in a dry hydrogen atmosphere, followed by furnace cooling. From the material produced in this way, 10
A φ-6φ ring sample was prepared by photoetching. The Fe-Ni alloy used in this example was 8ONi-
5Mo-Fe permalloy C-based alloy.

Table 1 shows the chemical composition and f of the ultrathin permalloy according to the present invention.
f! 5 shows the construction process. Also, their excitation frequency is 1kHz
Table 1 also lists the measurement results of the core loss per cycle at 1 kHz and 100 kHz, the core loss per cycle at an excitation frequency of 1 kHz after resin molding, and the Vickers hardness of the sample surface after heat treatment.

As is clear from Table 1, the inventive examples (1) to (2) have lower AC core loss and greater Vickers hardness than comparative examples (2) to (0). Furthermore, the greater the hardness, the less the increase in AC core loss after molding. The reason why the hardness of Comparative Example (2) is large is because the heat treatment temperature was low and the processing strain was not released, and its magnetic properties were significantly inferior to those of the Inventive Example. Examples (2) and (2) of the present invention are the results when a cold-rolled material was magnetically annealed and then heat-treated at 1° 100°C, and when the cold-rolled material was directly heat-treated at 1100°C.

There is no difference in magnetic properties and hardness between the two, indicating that this heat treatment can also serve as complementary magnetic annealing. In Comparative Example (2), the heat treatment temperature was as low as 200°C, so no effect of the heat treatment was observed. As shown in the examples of the present invention, by changing the heat treatment conditions of the present invention, it is possible to control the magnetic properties and hardness of the material.

Below margin

Claims (1)

[Claims] 1) After cold rolling the Fe-Ni alloy to a thickness of 100 μm or less, magnetic annealing is performed, and then annealing treatment is performed in which the alloy is held at a temperature of 500°C or higher for 5 minutes or more in a nitrogen, nitrogen, or hydrogen atmosphere. A method for producing a Fe-Ni magnetic alloy thin plate, characterized in that: