JPS6256393A - Metallic filament having bamboo-like structure and its production - Google Patents

Abstract

PURPOSE:To obtain the titled filament which has high toughenss, excellent workability and uniform quality and in which single crystals bordering at the grain boundaries are continuous like bamboo by subjecting a specific metallic filament obtd. by melt-spinning of an alloy essentially consisting of Fe to a heat treatment at the temp. above the recrystallization temp. CONSTITUTION:The alloy such as Fe-Si, Fe-Al or Fe-Si-A4l essentially consisting of Fe in a raw material metal contg. part 3 is melted in a heating furnace 5 and is injected 4 from a spinning nozzle 2 of a crucible 1 under the regulated gaseous Ar 11 pressure into a cooling liquid 8 having a cooling liquid surface 9 formed by the centrifugal force in a cylindrical drum 6 rotated by a driving motor 7 and a belt 12. The injected alloy is cooled and solidified and the metallic filament 10 which is the polycrystal structural body having >=2 crystal grains within the section and the many crystal grains in the fiber axis direction as well is continuously taken up in the drum 6. The filament is then heat-treated at the temp. above the recrystallization temp. in a vacuum or inert atmosphere. The titled filament which has just one crystal grain in the orthogonal section and in which the grain boundaries 13 exist like bamboo joints approximately perpendicularly to the fiber axis direction and single crystals are continuously connected in the axial direction at the intervals of >=2 times the diameter is obtd.

Description

[Detailed Description of the Invention] [Field of Industrial Application] What is the present invention? The present invention relates to a metal filament having a structure in which one crystal is continuously connected in a bamboo-like manner with grain boundaries as boundaries (hereinafter, this structure is referred to as a bamboo-like structure), and a method for manufacturing the same.

[Prior Art] A cooling liquid layer is formed on the inner peripheral surface of a rotating cylindrical hollow drum using centrifugal force, and molten metal is linearly injected into the liquid layer as a jet. One of the inventors of the present invention discovered that molten metal solidifies into a thin metal wire and previously filed a patent application (Japanese Patent Laid-Open No. 55-L64948).
Hereinafter, this method will be referred to as the rotating liquid spinning method.

Later, it became clear that continuous metal filaments could be obtained even in Fe-5i alloys by using the rotating liquid spinning method, and the present applicant and others have already filed a patent application (Japanese Patent Application No. 59-210893). The metal filament obtained by this method had a so-called polycrystalline structure, with crystal grains of 2 m or more in length in a cross section perpendicular to the fiber axis, and a large number of crystal grains arranged in the fiber axis direction. .

[Problems to be Solved by the Invention] The present inventors are conducting research on the development of applications for high-quality metal filaments, and in the process, it is desired to further improve the physical properties of the filaments. It's arrived. As a means for this improvement, it may be possible to change the polycrystalline type to single crystalline type. In other words, in general, if a polycrystalline metal filament can be made into a single crystal, it is expected that mechanical properties such as inertia will be greatly improved, and magnetic properties will also be modified into interesting properties. . That is, the present invention aims to provide a spun polycrystalline metal filament modified into a single crystalline filament.

[Means for Solving the Problems] The metal filament of the present invention is characterized in that single crystals are continuously connected in a bamboo-like manner with grain boundaries as boundaries, and the bamboo-like structure filament has the following features: A hot claw tool that injects molten metal through a spinning nozzle into a cooling liquid formed by centrifugal force in a rotating cylindrical drum, and recrystallizes the continuously wound metal filament in a cooling solidification branch drum. 1
Obtained by heat treatment at a temperature of :.

[Operation] Solidification methods and strain annealing methods are well known as techniques for single crystallizing alloys.

The solidification method is a method of producing a single crystal by using solidification from a metal melt, and the method of annealing a heated metal generates new crystal grains by annealing the heated metal. It is also called the II-crystallization method because it utilizes a recrystallization technique called crystallization. In the latter strain annealing method, a specimen formed into a linear or plate shape is first annealed at -1@ to form an aggregate of as fine and uniform crystal grains as possible, and then a moderate amount of annealing is applied to the specimen. This is done by applying a strain of 100% and then gradually heating it to a relatively high temperature from one end.

However, the present inventors succeeded in obtaining a metal filament with a characteristic structure using a completely new method. That is, by directly heat-treating at the temperature of the recrystallization hot tool H in a vacuum atmosphere, without performing processes such as preliminary annealing or wire drawing to increase strain,
They discovered that it was possible to obtain a metal filament with a completely new structure in which single crystals are connected and formed into a bamboo-like structure, leading to the completion of the present invention.

The present invention will be explained in more detail below.

First, a rotating liquid spinning method for producing polycrystalline metal filaments will be explained.

The basic part of the method is as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 55-64948, in which the circumferential speed of the four-wheeled film layer of the cylindrical drum is substantially the same as or lower than the molten metal injection speed from the spinning nozzle. If you do it a little faster than that, the cross section will be uniform.
A metal filament with good properties can be obtained.

In addition, the cooling liquid used in the present invention 11 may be a pure liquid, a solution, an emulsion, etc. The thin wire after spinning may be directly subjected to the next step, but the wire drawing using a die It is also possible to supply it to the next process after processing.
It is. The one shown in FIGS. 7 and 8 has an inner diameter of 500 mm.
Example manufacturing equipment having a rotating drum of 111,110 mm, and can use spinning nozzles with various hole diameters (gm). For example, while adjusting the argon gas pressure,
Spray molten metal at a speed of 0m/win to a depth of 20mm
A metal filament can be obtained by placing it in water (25°C). The rotating drum may be oriented horizontally or vertically, and the surface speed of the water film layer in the rotating drum in this case is 460 m/s.
In, the angle of approach of the molten metal flow into the water film layer is preferably 60°, and the distance between the spinning nozzle and the cooling liquid surface is preferably 3 m.

Although the type of metal constituting the metal filament according to the present invention is not limited, the most typical one is an Fe-based alloy. Furthermore, there are no restrictions on the type, number, blending ratio, etc. of the additive elements constituting the Fe-based alloy, such as Fe-Si alloy, Fe-Al alloy, Fe-3
Non-limiting examples include t-Al alloys, but in the following explanation Fe-
The effects of the present invention will be described with a focus on Si-based alloys.

According to the research conducted by the present inventors, the structure of the Fe-Si alloy obtained by spinning in a rotating liquid is that in the as-spun state (hereinafter abbreviated as As 5puII+), two or more metal filaments are present in the cross section of the metal filament. It was recognized that the fiber had a polycrystalline structure, with many crystal grains in the direction of the fiber axis. As mentioned above, the present inventors predicted that if such a polycrystalline structure could be controlled into a single crystalline structure, it would be possible to significantly improve both mechanical and magnetic properties.

Therefore, various heat treatments were tried in order to obtain a metal filament having a single crystal structure, and a metal filament having a bamboo-like structure was obtained using the following method. The method is as
This is a method in which the filament is placed in a vacuum atmosphere without any preliminary operation and heat-treated at the recrystallization temperature and the temperature above the claw tool.

The metal filament thus obtained has only one crystal grain in the cross section perpendicular to the fiber axis, and the 11 grain boundaries are located in a plane almost perpendicular to the fiber axis direction, and are shaped like bamboo nodes. , and generally more than twice the W&fiber diameter
The single crystals are continuous in the fiber axis direction at intervals of , creating a bamboo-like structure as a whole.

The reason why such a bamboo-like structure can be obtained by heat treatment without any preliminary operation has not been fully elucidated, but it is probably due to the state of the structure formed during spinning and the It is presumed that/or the strain introduced into the filament during spinning plays an important role in the generation of the bamboo-like structure, and that such a bamboo-like structure is generated by heat treatment. .

In this way, the As 5pun filament can be easily made into a bamboo-like structure by simply heat-treating it, making it extremely bendable and elongating very thickly in the tensile test, making it unsuitable for industrial purposes. It is a material that is easy to handle.

It is also possible to cut out a part of a metal filament with a bamboo-like structure and use it as a single crystal.

In this case, since they are cut from metal filaments of the same diameter, single crystals with uniform diameters can be obtained, and single crystals with different orientations in the wira axis direction can be obtained.

Note that metal filaments having a bamboo-like structure can be processed at a higher level, and can also be subjected to wire drawing and rolling.

In order to develop a bamboo-like structure, it is sufficient to perform heat treatment at a temperature higher than the re-solidification temperature, and if a thermal gradient furnace or the like is used, a bamboo-like structure can be obtained in a short time. Examples will be shown below, but various conditions are not limited by the examples.

Example 1 Example 1 Fe-
8.5 tons 34% St continuous filament.

1200℃ in an atmosphere of about 1 tart or less Te 0.5,1
, and was subjected to heat treatment for 2 hours. The heat-treated filament was capable of tight bending and showed large elongation in the tensile test. Figure 5 shows the strength and elongation curve.

The structure of the filament heat-treated at 1200° C. for 2 hours had a bamboo-like structure as shown in FIG. 13 represents a grain boundary.

Example 2 Fe with a diameter of 132 gm obtained by spinning in a rotating liquid
- Continuous filament made of 8.0 wt% St, about 0.5
Heat treatment was performed at 1000° C. for 1 hour in an atmosphere of torr or less. The heat-treated filament was capable of tight bending and showed large elongation in a tensile test. Figure 6 shows the strength and elongation curve.

The structure of the filament heat-treated at 1000° C. for 1 hour had a characteristic bamboo-like structure as schematically shown in FIG.

Example 3 Fe-
Continuous filament made of 25% Al.

Heat treatment was performed at 1200° C. for 1 hour in an atmosphere of about 0.1 torr or higher. The heat-treated filament had a bamboo-like structure as shown in FIG.

Example 4 Fe with a diameter of 1354 m obtained by spinning in a rotating liquid
A continuous filament of -5,2A I -2,7S i was heat treated in the same manner as in Example 3. The heat-treated filament had a bamboo-like structure as shown in FIG.

[Effects of the Invention] Since the present invention is configured as described above, a homogeneous bamboo-like metal filament with high toughness and good workability can be easily provided. It has also become possible to cut out a part of it and use it as a single crystal.

[Brief explanation of the drawing]

Figures 1 to 4 are explanatory diagrams schematically showing a metal filament with a bamboo-like structure, Figures 5 and 6 are strength and elongation curves of the filament, and Figures 7 and 8 are the equipment used to carry out the rotary underwater spinning method. FIG. 1... Crucible 2... Spinning nozzle 3...
Raw metal storage section 4... Molten metal flow 5... Heating furnace
6... Rotating drum 7... Drive motor,
8...Cooling liquid 9...Cooling liquid level 10...
・Metal filament 11...Inert gas 12・
...Belt 13...Grain boundary Applicant: Yudo Oonaka, Toyobo Co., Ltd., September 26, 1985 Patent Application No. 192352, filed in 1985, 2, title of invention 3, 1. Relationship between Patent Applicant 4, Agent 5, Subject of Amendment 1 TSR, "Detailed Description of the Invention" Column 6, Contents of the Amendment The attached sheet "Errata" will be corrected. "Delete" a column means to delete the words in the incorrect column) Correct
Misprint (2). (“Deletion” in the correct column means deletion of words in the incorrect column) [Example] Example 1 Fe-
A continuous filament made of 6.5% Si was heated to about 1 torr.
Heat treatment was performed at 1200° C. for 0.5.1° for 2 hours in an atmosphere of 0.5°C or less. The heat-treated filament was capable of close contact and showed large elongation in the tensile test. Figure 5 shows the strength and elongation curve. The structure of the filament heat-treated at 1200°C for 2 hours had a bamboo-like structure with a distance between grain boundaries of 0.5 to 10.5 mm, as shown in Figure 1 (13 represents grain boundaries). . The inductance of this metal filament was measured by the following method. Measurements were performed using the following method. In other words, using a urethane wire with a diameter of 35 μm, the inner diameter is 0.3 μm.
1 width 0.3■. A coil with 60 turns is produced, and both ends of a lead wire drawn out from the coil are connected to an impedance analyzer. Then, a metal filament was passed through this coil, and the inductance was measured by shifting the position of the metal filament in the fiber axis direction. The inductance value was read after 30 seconds had elapsed by applying a magnetic field to the coil at a frequency of 100 KHz and a current value of 0.1 mA at each measurement position. As a result, the inductance showed a maximum value (L□X) of 6.5 μH at a certain position, and a minimum value (L+a+n) of 3.6 μH at another position, and the inductance in the filament fiber axial direction was 8 and L a+
It fluctuated sharply in the range of In (L--x/L
ll1in = 1.8). It has been confirmed that such a sharp fluctuation in inductance is closely related to the length and crystal range of the single crystal part of the bamboo-like metal filament. For comparison, Fe-6 with a normal polycrystalline structure
, 5 wt% Si metal filament (diameter 155 μm)
When the inductance was similarly measured for an amorphous metal filament of Fe-10 atomic % 5t-15 atomic % B (diameter 126 μm) without grain boundaries, the inductance in the fiber axis direction was slightly different (L-8/ L1n<
1.2) There was no sharp change in inductance as shown by the metal filament with a bamboo-like structure. Example 2 Fe-
Approximately 0.5 t of 8.0 wt% Si continuous filament
Heat treatment was performed at 1000° C. for 1 hour in an atmosphere of orr or less. The heat-treated filament was able to be tightly curled and showed large elongation in the tensile test. 6th
The figure shows the strength and elongation curve. The structure of the filament heat-treated at 1000 DEG C. for 1 hour had a characteristic bamboo-like structure as schematically shown in FIG. Example 3 Fe-
A continuous filament made of 25% by weight of Al was approximately 0.1 to
Heat treatment was performed at 1200° C. for 1 hour in an atmosphere of rr or less. The heat-treated filament had a bamboo-like structure as shown in FIG. Example 4 Fe-
A continuous filament of 5.2 wt % A 1-2.7 g % si was heat treated in the same manner as in Example 3. The heat-treated filament had a bamboo-like structure as shown in FIG. [Effects of the Invention] Since the present invention is configured as described above, a homogeneous bamboo-like metal filament with high toughness and good workability can be easily provided. As a result, it will be easy to apply it to various magnetic sensor materials, for example, and a significant expansion of the field of application can be expected. It has also become possible to use it as a single crystal by cutting out a part of the bamboo-like metal filament. 4. Brief explanation of the drawings Figures 1 to 4 are explanatory diagrams schematically showing a metal filament with a bamboo-like structure, Figures 5 and 6 are strength and elongation curves of the filament, and Figures 7 and 8 are rotating liquids. FIG. 2 is an explanatory diagram of an apparatus used to carry out a medium spinning method. 1... Crucible 2... Spinning nozzle 3...
Raw metal storage section 4... Molten metal flow 5... Heating furnace
6... Rotating drum 7... Drive motor
8...Cooling liquid 9...Cooling liquid level 1o...
Metal filament 11... Inert gas 12...
・Belt 13...Grain boundary Applicant: Itsu Ohnaka, Rikai Toyobo Co., Ltd. Procedural Amendment Honor (, R&Ordinance) December 11, 1985 Patent Application No. 192352 of 1985 2, Title of the Invention 3, Amendment Patent applicant 4, Agent address: 4075 Shishiko Jin-ru, 2-3-7 Rei M, Kita-ku, Osaka, Date of amendment order: November 25, 1985 (Date of dispatch) 7, Amendment Contents September 26, 1985 Commissioner of the Japan Patent Office Black 1) Yu Akira 1, Indication of the case 1985 Patent Application No. 192352 2, Title of the invention 3, Person making the amendment Relationship with the case Patent applicant 4 , Agent address: Shishiko-1-', 2-3-7 Dojima, Kita-ku, Osaka
4075, Date of amendment order (Showa year, month, day) (shipment date) 6. Subject of amendment 7o Contents of amendment The amendments will be made as shown in the attached "Errata."

Claims (5)

[Claims] (1) A metal filament characterized by having a structure in which single crystals are continuously connected in a bamboo-like manner with grain boundaries as boundaries. (2) The metal filament according to claim 1, which is made of an alloy mainly composed of Fe and is obtained by heat-treating a filament obtained by melt spinning at a temperature equal to or higher than the recrystallization temperature. (3) The metal filament according to claim 2, wherein the alloy is selected from the group consisting of Fe-Si alloy, Fe-Al alloy, and Fe-Si-Al alloy. (4) Molten metal is injected through a spinning nozzle into a cooling liquid formed by centrifugal force in a rotating cylindrical drum, and the metal filament is continuously wound up in a cooling solidification branch drum and recrystallized. A method for producing a metal filament, characterized by heat treatment at a temperature higher than that temperature. (5) Fe-Si alloy, Fe-Al alloy and Fe
5. The method of manufacturing a metal filament according to claim 4, wherein the metal filament is manufactured using an alloy selected from the group consisting of -Si-Al alloys.