JPS5931848A - Amorphous alloy having superior forming capacity - Google Patents

Abstract

PURPOSE:To obtain an amorphous alloy having superior forming capacity by adding a specified element to an alloy for a magnetic material consisting of Fe, B, Si and C so that the atomic percentages of the elements satisfy specified relational equations. CONSTITUTION:This amorphous alloy has a composition represented by formula I (where Q is As, Mo, Nb, W, Ta, Ti or Sb, and the atomic percentages V-Z of the elements satisfy equations II-V). By adding the element Q, the amorphous state forming capacity can be increased remarkably without deteriorating the magnetic characteristics.

Description

[Detailed description of the invention] The present invention relates to an amorphous alloy with excellent formability.

Amorphous alloys are materials in which crystallization is prevented by injecting a molten alloy through a nozzle and rapidly solidifying it on a moving cooling body at a speed of 10' to 106° C./approx. For production on a normal industrial scale, a single roll method is most suitable as a cooling body. A method for manufacturing an amorphous alloy using a single roll method will be explained. Figure 1 shows a case where amorphous alloys are produced in small quantities on a laboratory scale, and the central axis of the nozzle 2 does not have to pass through the central axis of the roll 4, and the gap between the tip of the nozzle 2 and the surface of the roll 4 is arbitrary. can be taken. That is, it is sufficient if the molten gold [6] can be injected onto the surface of the roll 4.

However, when manufacturing several hundred ko on an industrial scale, it is difficult to simply tilt the nozzle 2 because the weight of the molten metal 6 is large. Therefore, as shown in FIGS. 2 and 3, the easiest method is to have the center axis of the nozzle 2 be vertical and pass through the center axis of the roll 4. However, in this case, it is important to set the gap between the nozzle 2 and the roll 4 to a constant small value. If the gap distance is too long, an amorphous alloy will be produced that is non-uniform and has many hole-like defects. The gap between the nozzle 2 and the roll 4 changes depending on the eccentricity of the roll when it rotates.

Now, on an industrial manufacturing scale, amorphous alloys must be easy to make. That is, it is important to find alloy compositions and manufacturing conditions that facilitate the formation of amorphous alloys.

Up until now, there has been a misconception regarding the ease of manufacturing amorphous alloys. That is, the manufacturing conditions for amorphous alloys and the ability to form amorphous alloys have rarely been considered separately.

The manufacturing conditions for amorphous alloys include the amount of molten metal injected from the nozzle, the temperature at the time of molten metal injection, the shape of the nozzle slit,
The problem lies in appropriately selecting the circumferential speed of the cooling roll, forced cooling conditions for the cooling roll, and in the case of a single roll method, the size of the gap between the nozzle and the roll.

The ability to form an amorphous alloy is due to differences in inherent physical properties such as surface tension, kinematic viscosity, and vitrification temperature of alloys exhibiting a specific composition range under the same manufacturing conditions. This shows how difficult it is to

Therefore, it can be said that the factor responsible for the ability to form an amorphous alloy is the composition of the alloy, that is, the atomic composition of the alloy. When judging the ability to form an amorphous alloy from the results, it should be judged separately from the factors of manufacturing conditions.

When amorphous alloys are manufactured under constant manufacturing conditions, alloys with excellent formation ability should behave differently from other alloys. That is, one of the important things regarding the formation of an amorphous alloy is the stability of the puddle formed by the molten metal between the nozzle and the cooling roll. It is known that the stability of this paddle is related to the surface tension and kinematic viscosity of the molten metal, and can vary greatly depending on the type of added element, even if it is in a small amount.

Amorphous alloys used as conventional magnetic materials have poor formability and are not easy to manufacture.

An object of the present invention is to provide an amorphous alloy with excellent formability by adding specific elements to a conventional alloy composition for magnetic materials.

The gist of the present invention is as follows.

That is, it has a composition represented by FevBwSixCyQz, and the fifth element represented by Q is As, Mo, and Nb.
, W%Ta%Ti, Sb.
species element, and each of the above atomic % V, W, X
It is an amorphous alloy with excellent formability, characterized in that %Y%Z satisfies the following relational expression.

V='l 00- (W+X+Y+Z)2W+X+Y
+Z=22~44 In particular, the present invention has been completed by discovering an alloy composition range that can significantly enhance the ability to form an amorphous state without deteriorating the magnetic properties.

First, the formation of an amorphous alloy will be explained. As shown in FIG. 4, the amorphous alloy is a molten alloy 6 injected from a nozzle 2.
is produced by forming puddles 8 on cooling body rolls 4. That is, the paddle 8 begins to solidify from the contact surface of the roll 4, and solidifies as it spreads to the opposite surface of the roll 4, that is, the free surface. The stability of this paddle 8 depends on the viscosity and surface tension of the molten metal. As shown in FIG. 4, surface tension regulates the bulge of the paddle 8 between the nozzle 2 and the roll 4, and the conditions for the shear force at the boundary line 10 between the liquid and solid of the molten alloy in the paddle 8 are What gives is viscosity.

In FIG. 1, if the injection speed of the molten alloy at the molten alloy injection point 12 is Vy, and the roll circumferential speed of the roll 4 surface is Vx, then these represent the component of the speed (2) of the molten alloy in the paddle 8. In this case, the amount of the molten alloy flowing into the nozzle 8 and the amount of the ribbon of alloy flowing out are equal, and the divergence is considered to be O, so the following relationship holds true.

The kinetic energy of the paddle is 1/2ρV! Therefore, this gradient becomes the force FE. This force must be balanced with the frictional force and shearing force Fs inside the nozzle, so ρ: density η: viscosity S: cross-sectional area of molten alloy (2) = (3), so η/ρ is It is generally referred to as kinematic viscosity. It can be said that the balance of shearing force inside the paddle is determined by the relationship between the kinematic viscosity, the injection speed of the molten alloy, and the peripheral speed of the roll.

On the other hand, the stability of the paddle shape can be considered as follows.

The surface tension F on the paddle liquid outer surface 14 in Figure 4 is expressed as R1, the maximum radius of curvature of the paddle, and R1, the minimum radius of curvature of the paddle.However, since the surface tension (2) and (5) are balanced where they are equal, the following formula holds true. do.

That is, the stability of the paddle is determined by the balance between the surface tension, the injection speed, and the peripheral speed of the roll, and in equation (6), if the left side is larger than the right side, the stability is good.

When looking at the elements added to Fe in alloys from the above perspective, several characteristics can be seen. Examples of elements that reduce surface tension include O%S%8e. These are nonmetallic elements that are easily dissolved in iron in a solid state. On the other hand A
s%Mo%Nb, W%Ta.

Ti, 8b, etc. tend to increase surface tension.

Next, the additive elements that increase viscosity include As%MO1Nb,
W, Ta, Tj, Sb, etc. are recognized, and the elements to be reduced are P, S, 0. These are components such as At that deteriorate the ability to form an amorphous state.

In the present invention, As is used to improve both surface tension and viscosity and to improve the ability to form an amorphous state.

One selected from Mo, Nb, W, Ta, Ti, and Nb was added.

Next, the reason for limiting the atomic percent relational expression of the amorphous alloy of the present invention will be explained.

Since this alloy is a quinary alloy and does not contain anything other than inevitable impurities, the sum of each atomic percent is 100.

V-4-W-4-X+Y+Z= 100 Therefore ■= 1
0'0- (W+X y+z) next KZW+X+Y+Z
The reason for limiting it to =22-44 is as follows. That is, the above-mentioned metalloid component has excellent ability to form an amorphous state within the range of 22 to 44 at. Can not.

Next, the reason why we limited the content of Si to the range of 2 to 19 at% was because the ability to form an amorphous state decreases in both cases when it is less than 2 at% and exceeds 19 at%. X=
It was limited to a range of 2 to 19.

Next, F 87g , 36 Bg-1g SIg ~1
A large number of amorphous alloys were manufactured by changing the contents of C and As in the quinary system of g Cy ASZ, and the plate thicknesses of the formed amorphous alloys were investigated, and C,! Figure 5 shows the uniform line of plate thickness with the content of :AS on both axes. In Fig. 5, an amorphous alloy is easily formed within the specific component range of C and As, and the range of C and As in which a plate thickness of 40 μm or more can be obtained is in the range of 0.01 to 1.0 at%. . That is, the atomic percent of each is as follows.

Y = 0.01 ~ 1.0 Z = 0.01 ~ 1.0 j (If you add both equations D, Y + Z = 0.02 ~
An atomic percent relational expression of 2.0 is obtained.

In this example, As was explained, but other materials such as Mo and Nb may be used.

Similarly for W, Ta, Ti%sb, Y-1-Z=0
．． The relationship between 02 and 2.0 holds true.

Example 1 By adding C and As to Fe-8i-B alloy, 1
Molten steel was prepared at 300°C and injected from a nozzle onto rotating rolls at a cooling rate of 10' to 106°C/sec to produce an amorphous alloy. Table 1 shows the plate thickness of the manufactured alloy.

As is clear from Table 1, the alloy of the present invention has a thicker plate and superior formability compared to the comparative alloy.

Example 2 Mo, W% Ti, N in Fe-84-B-C alloy
b was added to form a molten alloy at 1350°C, and the alloy was injected onto a rotating roll at a cooling rate of 10' to 1()6°C/
An amorphous alloy was made using see, and the plate thickness of the amorphous alloy is shown in Table 2.

Table 2 shows that the alloy of the present invention has a thicker plate and superior formability compared to the comparative alloy which does not satisfy the composition range of the present invention.

As is clear from the above examples, the present invention was able to obtain an amorphous alloy with excellent formability by limiting the alloy composition of the amorphous alloy.

Table 2

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view showing the relationship between the nozzle and the roll surface when producing amorphous alloys in small quantities, and Figures 2 and 3 are diagrams showing the relationship between the nozzle and the roll surface when producing amorphous alloys on an industrial scale. FIG. 4 is a schematic cross-sectional view showing the relationship between the nozzle and the roll surface, FIG. 4 is a schematic cross-sectional view showing the formation process of an amorphous alloy in the single roll method, and FIG.
The figure is a plate thickness contour diagram showing the relationship between the C and As contents of the Fe-B-8i-C-As alloy and the plate thickness of the manufactured amorphous alloy. Agent Takeo Nakaji 1st I! 1 Figure 2 Figure 3 Figure 400

Claims (1)

[Claims] (1) It has a composition represented by FevBwSixCyQz, and the fifth element represented by Q is As, Mo
, Nb, W, Ta%Ti, any one element selected from 8b, and each of the above atomic%■,
An amorphous alloy with excellent formability, characterized in that w, x, y, and z satisfy the following relational expression. V= 100- (W+X+Y+Z)2W+X+Y+Z=22~44 X=2~19 y+2=o, o2~2.0