JPS6323243B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for improving the core loss of an amorphous magnetic alloy ribbon.

Recently, a method has been proposed in which a magnetic material is ultra-rapidly cooled from a high-temperature molten state to produce a thin ribbon with a random (asynchronous) structure in which the atomic arrangement is similar to that of a liquid. This material has no anisotropy in principle,
High electrical resistance and 1/1 iron loss compared to silicon steel sheet
It has the advantage that it is extremely low, about 5, and can easily be obtained with a thin thickness. Therefore, it is expected to be used as an iron core for power transformers. However, the core loss value of this amorphous magnetic alloy ribbon is worse than the theoretically predicted value. The cause is said to be large eddy current loss. Further, there are problems such as poor thermal stability.

On the other hand, it has been proposed to improve iron loss by applying strain to the surface of a silicon steel plate to subdivide the magnetic domains. Therefore, when the present inventors conducted an experiment in which this improvement method was applied to an amorphous magnetic alloy ribbon, it was not possible to obtain the same effect as when applied to a silicon steel plate. In addition, as a practical problem, in the case of power transformers, it is necessary to perform strain relief annealing after forming into a wound core, but this annealing completely eliminates the effect of subdividing the magnetic domains due to the introduction of strain. I end up. Furthermore, if annealing is performed at a temperature that does not eliminate this effect, the effect of annealing will not be sufficiently achieved. Under these circumstances, the inventors conducted further studies and found that when a linear heat-affected zone is partially introduced into an amorphous magnetic alloy ribbon, the iron loss temporarily deteriorates, but after annealing, the iron loss decreases. found that the iron loss was improved compared to one that did not introduce heat.

Based on this knowledge, the present invention solves the problems when a wound core such as a wound core for a power transformer is constructed from an amorphous magnetic alloy ribbon.

That is, the present invention provides a Fe-Si-B amorphous magnetic alloy thin strip with a width of 0.5 mm or less, a depth of 1/2 or less of the plate thickness, and a spacing of 1 A heat-affected zone of ~10 mm filaments is introduced, and then annealed for 1 to 60 minutes in the temperature range expressed by the formula, where Ta = annealing temperature Tx = crystallization temperature. The present invention relates to a method for improving iron loss of an Fe-Si-B amorphous magnetic alloy ribbon.

The gist of the present invention will be explained below.

In the present invention, first, an amorphous alloy having a composition of, for example, Fe--Si--B is melted and a ribbon is manufactured by an appropriate method such as a rolling method. Next, the ribbon is intermittently heated in the widthwise direction (width direction) at an angle to the longitudinal direction of the ribbon by an appropriate means such as an electron beam, a laser boom, an arc, a spark, or contact with a high-temperature object. Grant. In this case the width of the heat affected zone is 0.5
The depth is preferably 1/2 or less of the plate thickness, and the distance between adjacent heat affected zones is preferably about 1 to 10 mm. Also, the appropriate angle to the longitudinal direction is 60 to 90 degrees. After winding the amorphous magnetic alloy ribbon into which the heat-affected zone has been introduced (in this case, it is effective to wind the side to which heat has been introduced outward to obtain a tension effect) and constructing the wound core, it is placed in a magnetic field. Perform strain relief annealing. The annealing temperature (Ta) at this time is desirably within the range of Tx-100°C<Ta<Tx+50°C for about 1 to 60 minutes, where Tx is the crystallization temperature of the alloy.

When annealing is performed under these conditions, the heat-affected zone, where heat has been introduced in advance, crystallizes faster than other parts, and as a result, the 180° magnetic domain in that part is subdivided, significantly improving iron loss. .

Examples of the present invention will be shown below.

Example 1 Composition of Fe ₇₈ Si ₁₂ B ₁₀ (atomic %), thickness
40μm, width 20mm amorphous magnetic alloy ribbon
Electrons with a beam diameter of 0.2 mmφ were irradiated with a current of 0.2 milliamperes accelerated at 40 kV at a scan speed of 2 m/min parallel to a direction at an angle of 80° to the longitudinal direction of the ribbon. The irradiated width was 0.3mm and the depth was
They were 15 μm (less than 1/2 of the board thickness) and 4 mm apart. When the irradiated area was examined by X-ray diffraction, it remained amorphous. This thin ribbon of about 3 m was wound into a toroidal shape with an inner diameter of 50 mm, and heated to 50°C x 10 m
Annealing for minutes was carried out in argon.

Note that the crystallization initiation temperature of Fe ₇₈ Si ₁₂ B ₁₀ was 505° C. as measured by a scanning calorimeter (DSC).

The magnetic properties of this sample measured at 50Hz were as follows.

B ₁ = 1.50T (Tesla) W _1.3/50 = 0.086watt/Kg However, B ₁ is the magnetic flux density at 1Oe, W _1.3/50 is 50
Shows iron loss at Hz and 1.3T.

Also, the iron loss W _0.6/3000 at 3000Hz and 0.6T is
It was 4.1watt/Kg.

As a comparison, a ribbon of the same composition and size that was not affected by heat was annealed under the same conditions, and its magnetic properties were as follows.

B ₁ = 1.51T (50Hz) W _1.3/50 = 0.094watt/Kg W _0.6/3000 = 6.3watt/Kg Example 2 Using a YAG laser, an amorphous magnetic alloy ribbon with the same composition and size as Example 1 was used. , beam diameter 0.1mmφ, irradiation density 10J/cm ² , width 0.4mm, depth
A linear heat-affected zone was introduced by irradiating parallel to a direction at a 70° angle to the longitudinal direction of the ribbon under the conditions of 15 μm (less than 1/2 of the plate thickness) and a spacing of 2 mm. X the irradiation area
When examined by line diffraction, it remained amorphous. Approximately 3 m of this ribbon was wound into a toroidal shape with an inner diameter of 50 mm, and annealed in hydrogen at 450°C for 10 minutes while applying a magnetic field of 10 Oe.

The magnetic properties of this sample measured at 50Hz and 3kHz were as follows.

B ₁ = 1.50T (50Hz) W _1.3/50 = 0.079watt/Kg W _0.6/3000 = 3.8watt/Kg After annealing under the same conditions for a thin strip of the same composition and size that was not irradiated with a laser beam for comparison. The magnetic properties of were as follows.

B ₁ = 1.52T (50Hz) W _1.3/50 = 0.088watt/Kg W _0.6/3000 = 7.0watt/Kg We have explained the case of a thin strip, but it can also be applied to a thin strip that has been cut to a predetermined size. Of course, it falls within the scope of the present invention.

Claims (1)

[Claims] 1. Width in a direction at an angle of 60 to 90 degrees with respect to the longitudinal direction of the Fe-Si-B amorphous magnetic alloy ribbon.
0.5mm or less, depth less than 1/2 of the plate thickness, spacing 1 to 10mm
After that, annealing should be performed for 1 to 60 minutes in the temperature range expressed by the formula: Tx - 100℃ < Ta < Tx + 50℃, where Ta = annealing temperature Tx = crystallization temperature. A method for improving iron loss of an Fe-Si-B amorphous magnetic alloy ribbon, characterized by: