JPS58358A - Production of thin amorphous alloy strip of superior soft magnetic characteristic and less fluctuation in characteristic - Google Patents

Abstract

PURPOSE:To obtain a thin amorphous strip of superior soft magnetic characteristics, uniform quality and good surface characteristics in the stage of producing the thin amorphous alloy strip by holding the surface temp. of cooling rolls within the range of the specific equation. CONSTITUTION:The crystallization temp. Tx of an amorphous alloy to be produced is beforehand determined with a differential thermal analyzer (DTA) or the like and the temp. TR deg.C of the surface of cooling rolls is maintained within the range of the following equation according to the amt. of the metolloid of the alloy (X at.%) and the temp. Tx. 12x-150<TR<TX-500+15X0. The molten alloy is flowed out onto the rotating rolls held in this specified temp. range and thin strip solidified to have a prescribed thickness is the thin amorphous strip of uniform quality and good surface characteristics which exhibits superior magnetic characteristics uniform over the entire length.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides excellent soft magnetic properties such as high magnetic flux density, low iron loss, and reduced longitudinal magnetic fluctuations when producing an amorphous alloy ribbon by a single roll method, a twin roll method, etc. The present invention relates to a manufacturing method for obtaining an amorphous alloy ribbon.

When producing amorphous magnetic alloy ribbon, the single roll method involves pouring the molten alloy onto the surface of a rotating roll and rapidly solidifying it, and the twin roll method involves pouring the molten metal onto the contact area of rotating rolls that are in contact with each other and rapidly solidifying it. However, in the conventional method, if the roll temperature is too low, wetting between the roll surface and the molten metal is poor, resulting in a ribbon with uneven cooling ability, and if the roll temperature is too high, The cooling capacity is insufficient, making it difficult to turn into amorphous, and in any case, there are some places where amorphization is insufficient, resulting in deterioration of magnetic properties or a tendency for the properties in the longitudinal direction to become uneven. Undesirable situations may occur. The present invention solves these problems and relates to a method for obtaining an amorphous alloy ribbon with excellent soft magnetic properties.

That is, the present inventor obtained the knowledge that there is an optimum roll surface temperature for magnetism depending on the alloy composition when manufacturing an amorphous alloy ribbon, and as a result of further detailed study, the optimum roll surface temperature was found to be the first. As shown in the figure, the crystallization m W (Tx ) of the alloy and the amount of the semimetal contained in the alloy (
We found that there is a correlation with fc.

That is, it was estimated that the upper limit of the Ik roll narrow surface WAIf could be expressed as tYTz-500+15z (°C) as a function of Tx and X, and that the lower limit temperature could be expressed as 12z-150 (C).

Amorphous alloys related to the present invention C, Fs, Co.

At least one kind of ferromagnetic transition metal of Ni 70-85
at- and B, 81. It is a so-called metalloid alloy consisting of 15 to 30 pieces of at least one of the semimetals C, P, and G. In addition, some of the ferromagnetic transition metals among the above alloy components are Cr*Mn+Mo*
Nb + Mut.

Tt+V*8E112! kl CI may be substituted with one or more types (total not more than l
The surface of the cooling roll is 12m-150 (C
) is higher than Tx -500+ 15 z E) By maintaining the i1 degree lower than E), uniform magnetic properties are obtained over the entire length of the ribbon.

That is, in the present invention, the crystallization temperature (Tx) of the amorphous alloy to be manufactured is determined in advance using a differential thermal analyzer (
DTA ), etc., and the iron surface impregnation of the roll is higher than 12 x -150 ('C) depending on the half-metal paulownia content (z itlg ) of the alloy and the crystallization temperature (Tx), and Tx
5 o, o-t-t 5 g (°C) lower i! Try to keep it in the degree range. Methods for maintaining the roll surface within a predetermined temperature range include circulating cooling water at an appropriate temperature within the roll depending on the desired temperature, or bringing the roll surface into contact with another medium. There is.

In this way, the molten alloy is flowed onto a rotating roll whose surface is maintained within the temperature range defined by the invention;
The ribbon solidified to a predetermined thickness is a homogeneous amorphous ribbon with good surface properties; it is uniform over its entire length and exhibits excellent magnetic properties.

The reason why the lower limit of the appropriate roll surface temperature depends on the amount of metalloid is presumed to be that the amount of metalloid weave is related to the wettability between the metal roll and the molten alloy. In other words, it is believed that if the amount of metalloids is large and the wettability with the roll is poor, this can be improved by increasing the temperature of the roll surface.

Moreover, the reason why the upper limit of the appropriate roll surface atto is related to the crystallization temperature is presumed to provide the critical cooling rate necessary for amorphization.

Example 1 An alloy having a composition of F.IB"4B14 (atomic mass) was made into a thin strip having a thickness of 25 to 35 μm using an iron hanger.

The temperature of the roll surface measured by a radiation thermometer and the corresponding iron loss of the ribbon W1,2475g (50Hz, 1.
The relationship between the iron loss at 28T@I1M) and the magnetic flux density Bl (magnetic flux cylinder at 1) is 9 as shown in the JR2 diagram. If the roll II surface 11 [is in the range of 40°C to 200°C, Wl, 24150 is 0.11 watt/~ or less, B1 is 1.4T or more, which is the crystallization start temperature of the zero alloy that shows excellent magnetic properties. (measured at a heating rate of 10 Vrntn) is 446°C, so according to calculations, the upper limit is 186°C.
°C, the lower limit was 66 °C, proving the oil properties (5) of the present invention.

Furthermore, as seen in this example, the temperature range where magnetic flux density is good is generally shifted to the higher temperature side than the temperature range where iron loss is good. Therefore, when placing importance on the magnetic flux tube 1, it is better to select the high temperature side within the range specified by the present invention.

Example 2 F @ 78 S l < 2 B. An alloy having the composition (atomic parts) was made into an amorphous ribbon in the same manner as in Example 1. Iron loss and magnetic flux density of this alloy ribbon and roll surface S
The relationship with degree is as shown in Figure 3. The thin strip spans the entire length. It can be seen that in order to obtain a low iron loss of 9 or less when 2w is 0.10 watt/1.26750, the roll surface temperature should be in the range of 120 to 360°C. The crystallization temperature of this alloy is measured to be 524°C, so the upper limit is calculated to be 354°C.
, the lower limit is 114°C, proving the validity of the present invention.

[Brief explanation of drawings]

Figure 1 shows F・84-2B16-□st2. Figure 2 shows the composition dependence of the appropriate roll surface temperature and crystallization start temperature Tx of the alloy. Figure 3 is “78”1
FIG. 2 is a diagram showing the influence of the a-ru surface temperature on the iron loss of the 2B1° alloy. In Figure 1, 'Wl, 2615°◎ <0.
1wmtt/kl? 0 0.1-0.12 Δ 0.12-0.15 C) No.
3 times 07 234

Claims (1)

[Claims] In a method for producing an amorphous alloy ribbon by a liquid quenching method using a roll, the temperature of the surface of the cooling roll (
Tm (°C)) is determined by the following formula (
1) A method for producing an amorphous alloy ribbon having excellent soft magnetic properties and having little variation in properties. 12g-150 (Tm<Tx-500+15g ・=(
1) Here, 2 indicates the total amount of semimetal ([child'4), Tx indicates the crystallization start temperature CC of the alloy.