JPH05148098A - Growth of fe-si-al-based alloy single crystal - Google Patents

Abstract

PURPOSE:To provide a method for growing an Fe-Si-Al-based alloy single crystal, capable of obtaining a single crystal having the same plane azimuth as in the seed crystal suitable for preventing generation of bubbles by gaseous Ar during growth of the single crystal. CONSTITUTION:In a method for growing an Fe-Si-Al-based alloy single crystal by putting a seed crystal 2 composed of an Fe-Si-Al-based alloy polycrystalline rod 1 and an Fe-Si-Al-based alloy single crystal in a crucible 3 (3a), melting (A) the polycrystalline rod 1 through the crucible 3 by heater and growing the Fe-Si-Al-based alloy single crystal, a prism-shaped seed crystal 2 is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for growing an Fe-Si-Al alloy single crystal, and in particular, a single crystal having the same plane orientation as that of a seed crystal can be obtained to prevent generation of bubbles during single crystal growth. The present invention relates to a method for growing an Fe-Si-Al alloy single crystal suitable for

[0002]

2. Description of the Related Art An example of a method for growing an Fe-Si-Al alloy single crystal will be described with reference to FIG. In the figure, 1 is F
It is a polycrystalline round bar sample of a Fe-Si-Al alloy produced by heating and melting raw materials of e, Si, and Al in a non-oxidizing atmosphere. Reference numeral 2 is a seed crystal of an Fe-Si-Al alloy single crystal, and this seed crystal 2 is housed in a small diameter portion 3a of a cylindrical crucible 3 called a Tamman tube made of alumina. The round bar sample 1 is stored in the large diameter portion 3b of the crucible 3. Here, the seed crystal 2 is (111), (110), (100) or (2
An appropriate plane orientation such as 11) is selected.

A carbon heater 5 accommodating a round bar sample 1 is set in a high-voltage high-frequency induction heating device 50 which is a single crystal growing device. The high-pressure high-frequency induction heating device 50 has an upper chuck 7 for fixing the carbon heater 5, a lower chuck 8 and a high-frequency heating coil 9 arranged around the carbon heater 5 in the furnace 6.

The apparatus 50 further comprises an upper sample rotation vertical drive unit 10 for rotating the carbon heater 5 and the crucible 3 outside, a lower sample rotation vertical drive unit 11, and Ar for supplying Ar (argon) gas into the furnace 6. A gas cylinder 12, a rotary pump 13 for evacuating the inside of the furnace 6, a pressure gauge 14 for measuring the pressure inside the furnace, a power source 15 for the high-frequency heating coil 9, and a copper for cooling the outside of the furnace 6 with a water flow, which are arranged around the outside of the furnace 6. A pipe 16 is provided. For the sake of explanation, the drawing of the carbon heater 2, the crucible 3, the sample 1, and the high-frequency heating coil 9 is enlarged compared to the furnace 6.

After setting the carbon heater 2 accommodating the round bar sample 1 and the crucible 3 in the apparatus 50, the inside of the furnace 6 is made to have an appropriate vacuum atmosphere by the rotary pump 13, and then the Ar gas cylinder 12 is used to put Ar inside the furnace 6. Gas is supplied to pressurize the furnace to, for example, 1 atm, 5 atm, and 10 atm. Evaporation of Fe, Si, and Al melted by pressurization is further prevented.

A high-frequency current is passed through the high-frequency heating coil 9,
The temperature of the carbon heater 5 near the high-frequency heating coil 9 is raised, and the heat is transmitted through the crucible 3 to melt a part of the round bar sample 1 and form a melted portion A. That is, the crucible 3 is indirectly heated by the high-frequency heating coil via the carbon heater 5, and the indirect heating prevents the crucible 3 from cracking.

The molten portion A is first formed near the junction between the round bar sample 1 and the seed crystal 2. At this time, the upper sample rotation vertical drive unit 10 is driven to rotate the carbon heater 2,
At the same time, the crucible 3 and the round bar sample 1 rotate to make the temperature distribution uniform.

In the state shown in the figure, the upper sample rotation vertical drive unit 10 is driven to rotate the carbon heater 5 and the crucible 3 and gradually move them downward as indicated by an arrow B to cool the melting portion A to cool the seed crystal 2 described above. Forming a single crystal having the same plane orientation as. Here, a part of the round bar sample 1 corresponding to the high frequency heating coil 9 forms a new melting part, but when the carbon heater 2 and the crucible 3 further move in the B direction, the melting part is cooled and a single crystal is formed. It is formed. Evaporation of Fe, Si, and Al is prevented by forming the melting portion A of the round bar sample 1 as a part.

Thus, the carbon heater 5 and the crucible 3 are moved by the drive unit 10 until the high frequency heating coil 9 corresponds to the upper portion of the round bar sample 1, and then the Ar in the furnace 6 is moved.
After degassing, the rotary pump 13 once evacuated and then brought to normal pressure, the single crystal round bar was taken out from the furnace 6,
The growth of the single crystal is completed.

Although the high-frequency heating coil 9 is fixed and the round bar sample 1 and the crucible 3 are moved together with the upper and lower chucks 7 and 8, the high-frequency heating coil 9 may be moved.

FIG. 3 and FIG. 4 show a conventional example, in which the above-mentioned Fe-
FIG. 4 is an enlarged cross-sectional view showing a main part and a cross-sectional view taken along the line AA ′ of FIG. 3, which are used for a method for growing a Si—Al alloy single crystal. The parts corresponding to those in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIGS. 3 and 4, the seed crystal 2 has a columnar shape and is housed in a small diameter portion 3a having a circular cross section.

[0013]

However, since the seed crystal 2 is cylindrical, the seed crystal is tilted (angle θ) as shown in FIG.
As shown in FIG. 3, a large clearance B is generated, and a single crystal in the direction indicated by the arrow C in FIG. 3 grows.
A single crystal with a different orientation from the orientation of the upper surface of will grow.

On the other hand, if the clearance between the crucible 3 and the small diameter portion 3a is eliminated, that is, if the diameter of the inner wall of the small diameter portion 3a and the outer diameter of the seed crystal 2 are substantially the same, the seed crystal 2 described above is used.
However, the path through which the supplied Ar gas is discharged through the gas vent hole 3c of the small diameter portion 3 is closed, and remains in the tapered portion 3d of the crucible 3 to cause bubbles in the grown single crystal. There is a problem such as occurrence of.

[0015]

The present invention is based on Fe-Si-
A seed crystal consisting of a polycrystalline rod of an Al-based alloy and a single crystal of an Fe-Si-Al-based alloy is housed in a crucible, and the polycrystalline rod is melted through the crucible by a heating means to produce Fe-Si-Al.
In a method for growing an Fe-Si-Al based alloy single crystal for growing a single crystal of a system alloy, the seed crystal is formed into a prismatic shape.

[0016]

This Fe-Si-Al alloy single crystal growing method prevents the occurrence of different orientations by providing an appropriate clearance and has the same plane orientation as the seed crystal.
A l-type alloy single crystal can be obtained, and bubbles are prevented from being generated during the growth of the single crystal.

[0017]

EXAMPLES Next, a method of growing an Fe—Si—Al alloy single crystal according to the present invention will be described. 1 and 2 are an enlarged cross-sectional view of a main part and a cross-sectional view taken along the line EE 'of FIG. 1, respectively showing an embodiment of a Fe-Si-Al alloy single crystal according to the present invention. The parts corresponding to those in FIG.
The description is omitted.

As shown in FIGS. 1 and 2, the seed crystal 2 is in the shape of a quadrangular prism and is housed in a small diameter portion 3a having a circular cross section.

The small diameter portion 3a of the seed crystal 2 is stored in the state shown in FIG.
As shown in, the ridge line portion 2a is close to or in contact with the inner wall of the small diameter portion 3a, and the side surface portion 2b maintains an appropriate clearance G with the inner wall of the small diameter portion 3a.

As described above, the ridge line portion 2a is brought close to or in contact with the inner wall of the small diameter portion 3a, so that the seed crystal 2 is housed without tilting (θ = 0), and the growth direction of the single crystal is as shown in FIG. The Fe-Si-Al-based alloy single crystal having the same plane orientation as the upper surface of the seed crystal 2 is obtained by proceeding in the direction as shown by the arrow F.

On the other hand, since the clearance G between the crucible 3 and the small diameter portion 3a is maintained, the supplied Ar gas does not remain in the taper portion 3d of the crucible 3 and the vent hole of the small diameter portion 3a is maintained. The air bubbles are prevented from being generated in the grown single crystal after being discharged through.

In the above description, the shape of the seed crystal 2 may be a polygonal prism shape such as a triangular prism, a hexagonal prism, an octagonal prism or the like instead of the quadrangular prism shape, and the amount of clearance may be adjusted.

[0023]

As described above, Fe-Si- according to the present invention
The method for growing an Al-based alloy single crystal is such that a seed crystal consisting of a polycrystalline rod of Fe-Si-Al-based alloy and a single crystal of Fe-Si-Al-based alloy is housed in a crucible, and heating is performed through the crucible. In a method for growing an Fe-Si-Al alloy single crystal in which the polycrystalline rod is melted to grow an Fe-Si-Al alloy single crystal, the seed crystal is formed in a prismatic shape, and thus the seed crystal is crucible. Since it can be stored without tilting inside, a single crystal with the same plane orientation as the upper surface of the seed crystal can be obtained, and since an appropriate clearance can be maintained between the seed crystal and the crucible,
There is an advantage in that it is possible to prevent the generation of bubbles due to residual Ar gas during single crystal growth.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part of a growth method of an Fe—Si—Al alloy single crystal.

FIG. 2 is a sectional view taken along the line E-E ′ of FIG.

FIG. 3 is an enlarged cross-sectional view of a main part of a method for growing an Fe—Si—Al alloy single crystal showing a conventional example.

FIG. 4 is a sectional view taken along the line A-A ′ in FIG.

FIG. 5 is a diagram showing an example of a method for growing an Fe-Si-Al alloy single crystal.

[Explanation of symbols]

 1 polycrystalline rod 2 seed crystal 3 crucible

Claims (1)

[Claims] 1. A Fe-Si-Al alloy polycrystalline rod and a Fe-Si-Al alloy single crystal seed crystal are housed in a crucible, and the polycrystalline rod is heated by heating means through the crucible. In a method of growing an Fe-Si-Al alloy single crystal in which Fe is melted to grow an Fe-Si-Al alloy single crystal, the seed crystal is formed into a prismatic shape.
Method for growing i-Al alloy single crystal.