JPH0239082B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a ferromagnetic wire in which the surface of a magnetically relatively soft ferromagnetic metal wire is coated with a glass layer containing a magnetically relatively hard ferromagnetic oxide, and a method for manufacturing the same. Manufacture permanent magnets, magnetic sensors, magnetic memory elements, switching elements, various elements with self-recovery functions, etc. by increasing the coercive force of magnetic thin metal wires, or by changing or shifting the B-H loop. The purpose of this invention is to provide a thin magnetic metal wire useful for. The ferromagnetic metal referred to in the present invention includes at least one element selected from the well-known group consisting of iron, cobalt, and nickel, and optionally includes titanium, vanadium, chromium, manganese,
A metal composition containing at least one element selected from the group consisting of copper, zinc, aluminum, zirconium, niobium, molybdenum, tungsten, silicon, carbon, boron, phosphorus, etc., and exhibiting ferromagnetic properties at room temperature. This is what we are doing. in particular,
Iron/nickel alloys such as permalloy and invar alloys; iron/cobalt alloys such as high cobalt alloys and permendure; iron/nickel/cobalt alloys such as perminvar; iron and iron/iron alloys such as so-called electric iron plates
Silicon alloys; iron/aluminum alloys such as Alperm; iron/silicon/aluminum alloys such as Sendust; iron/cobalt/vanadium alloys such as Vicaloy; iron/nickel/nickel alloys such as Kiunihue and Kiyunico.
Copper and cobalt/nickel/copper alloys; iron/chromium/cobalt alloys; iron/nickel/cobalt/aluminum alloys such as alnico; iron/carbon alloys; at least one selected from the group consisting of iron, cobalt, and nickel. A ferromagnetic material described in ordinary magnetism-related literature such as a so-called amorphous alloy containing one type of element and at least one element selected from the group consisting of boron, silicon, phosphorus, carbon, aluminum, etc. are doing. Furthermore, the glass referred to in the present invention refers to an oxide containing at least one element selected from the group consisting of barium, strontium, and lead, and iron, and B ₂ O ₃ .
Vitrified mixture of so-called glass-forming oxides such as S ₁ O ₂ , P ₂ O ₅ , GeO ₂ , As ₂ O ₃ , TeO ₂ , Sb ₂ O ₃ , and additives added as necessary. By heat treatment after glass formation, ferromagnetic phase microcrystals having a magnetoplumbite structure represented by so-called barium ferrite are precipitated. The temperature of the heat treatment for vitrification depends on the glass composition, but is preferably 300°C to 1000°C. In addition, the microcrystal referred to in the present invention is about 100 mm in diameter.
Crystal grains with a size equivalent to approximately 1 μm are intended; below approximately 100 Å, superparamagnetic behavior becomes noticeable, and above approximately 1 μm, grains have a multi-domain structure, both of which are important in terms of magnetic properties. Undesirable. The proportion of microcrystalline phase in the glass (space factor) is 0.1~
A value of 0.8, more preferably 0.4 to 0.7 is desirable, but unlike Alnico etc., it is not very sensitive. The thickness of the glass coating layer is preferably 0.05 to 0.4 times, more preferably 0.1 to 0.3 times, the diameter of the thin metal wire. If the glass coating layer is too thin, it will have less effect on the internal ferromagnetic metal of the coating layer,
If the glass coating layer is too thick, the effect of the internal ferromagnetic metal will not be significant. The magnetic material of the present invention can be produced by simultaneously extruding or drawing out a melted or sufficiently softened glass material and a melted metal composition using the so-called melt spinning method, Taylor method, etc., at a cooling rate of about 10 ² °C/second or more. A fine wire with a ferromagnetic metal surface coated with glass obtained by quenching at 300°C to 1000°C for a sufficient time to precipitate magnetoplumbite-type microcrystals as described above.
It can also be obtained by heat treatment for 0.5 to 50 hours,
In addition, a thin metal wire obtained by ordinary wire drawing is immersed in the melted glass composition and pulled up to obtain a glass-coated ferromagnetic thin metal wire, which is then subjected to the above-mentioned heat treatment to form a magnetoplumbite. It can be manufactured by an easily conceivable method such as precipitation of type microcrystals. In addition, the thin wire referred to in the present invention does not have a specified thickness or shape as can be seen from the fact that there are various manufacturing methods, but when manufacturing by melt spinning method, Taylor method, etc., it is preferably 0.1 μm to 100 μm. is 1μm~
It is desirable to have a wire diameter equivalent to 50 μm. Also,
If necessary, the thin wire of the present invention can be further coated with a conventional glass material. This will be explained below using examples. Example 1 Glass obtained by melting 12 g of B ₂ O ₃ , 53 g of BaCO ₃ , and 35 g of Fe ₂ O ₃ at 1350°C in a platinum crucible and rapidly cooling it on a copper plate, and 90 g of Fe and 10 g of Si were melted in a high frequency furnace in a vacuum and then rapidly cooled. The Fe-Si alloy obtained by
of Materials Scievce 13 (1978) 786, etc.) to obtain glass-coated ferromagnetic metal thin wires. The cross section of the wire is approximately circular and the diameter is approximately 20 μm.
The thickness of the glass layer was approximately 2 μm. to this thin line
Heat treatment was performed at 500°C to 1000°C for 20 hours, and measurements were taken. According to the results of X-ray diffraction, from about 600℃
It can be seen that the BaO・6Fe ₂ O ₃ phase is precipitated.
In addition, Table 1 shows the magnetic flux density of the sample measured in a magnetic field of 20 KOe and the coercive force when shaken with an amplitude of 20 KOe.

[Table] Example 2 Using the same glass and alloy materials as in Example 1 and using the same equipment, a thin wire with a diameter of about 21 μm and a glass layer thickness of about 3 μm was obtained. 850℃ for this thin wire
After heat treatment was performed for 20 hours, measurements were taken.
The results of measurements in a magnetic field of 20KOe showed that the magnetic flux density of the sample was approximately 10KG and the coercive force was 700Oe. Example 3 Glass with the same composition as Example 1 and Fe21.2g,
Ni78.5g, Mn0.3g (composition of so-called 78 permalloy)
Fe-
Using a Ni-based alloy and using the same equipment as in Example 1, a thin wire with a diameter of 25 μm and a glass layer thickness of about 1 μm was obtained. This thin wire was heat-treated at 700°C for 20 hours, rapidly cooled to room temperature, and then measured. The magnetic flux density of the sample at 20KOe was approximately 9KG, and the coercive force was approximately 80Oe. Furthermore, after applying a magnetic field of 20 KOe in the positive direction, the magnetic field was set to 0 Oe, and then a magnetic field of 200 Oe was applied in the negative direction to reverse the magnetization. After that, when the magnetic field was returned to 0Oe, the magnetization reversed again and pointed in the positive direction. This is-
Since the barium ferrite in the coated glass does not reverse in a magnetic field of 200Oe, even if -200Oe → 0Oe,
The magnetic field applied to the internal permalloy layer is 20KOe→
This is thought to be because it is almost the same as in the case of 0O ₂ , and if this phenomenon is used, it is possible to apply it to an element with a self-healing function.

Claims (1)

[Scope of Claims] 1. A ferromagnetic metal wire characterized in that the surface of the ferromagnetic metal wire is coated with glass in which ferromagnetic microcrystalline grains having a magnetoplumbite structure are precipitated. 2 A thin wire whose ferromagnetic metal surface is coated with glass obtained by simultaneously extruding or drawing a melted or sufficiently softened glass material and a melted metal composition and rapidly cooling at a cooling rate of 10 ² °C/sec or more.
A method for producing a ferromagnetic metal thin wire, characterized by heat treatment at 600°C to 1000°C for a sufficient time to precipitate magnetoplumbite type microcrystals.