JPH0364561B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for producing amorphous alloy powder used for various purposes such as raw materials for bulk compacts, electromagnetic clutches, abrasives, and electromagnetic shielding materials. It is something.

(Prior art) Amorphous alloy powder is melt-quenched, that is, the alloy is ejected from the molten metal through a nozzle, rapidly cooled on a moving cooling substrate, and the amorphous ribbon is crushed and powdered. The method is disclosed in US Pat. No. 4,290,808 (Japanese Unexamined Patent Publication No. 128,506/1982), US Pat.

Amorphous alloy ribbons are generally ductile when cast, and do not break even when bent 180 degrees tightly. Therefore, in order to produce amorphous alloy powder by the pulverization method, it is necessary to embrittle the amorphous alloy. For this purpose, the above-mentioned inventions have been proposed as specific means. That is, the invention described in US Pat. No. 4,290,808 is a method in which an amorphous alloy ribbon is held at a temperature necessary to cause embrittlement for a certain period of time, and then pulverized using a pulverizer. Further, the invention described in US Pat. No. 4,406,700 discloses that after hydrogen embrittlement of an amorphous alloy,
This is a method of pulverizing it.

The above method is certainly effective as a method for facilitating powderization by embrittling the as-cast amorphous ribbon. However, productivity is low because it requires steps such as heat treatment and hydrogen embrittlement treatment.

In order to improve productivity, an improved apparatus and method in which the casting process and the crushing process are integrated is described in Japanese Patent Application Laid-Open No. 120703/1983. According to the description in this publication, heat treatment is included as a pretreatment step for pulverization in order to facilitate pulverization. If heat treatment is not performed, it is recommended to use special equipment with strong crushing force, such as a hammer mill or knife mill, to make it possible to break it. This is because a device with a relatively small impact force, such as a ball mill, cannot improve the pulverizing effect. However, hammer mills and knife mills use normal amorphous materials (plate thickness 20 to 40μ).
Although m) is ductile, it is hard, so the mill is subject to severe wear and tear, and noise and vibration during operation of the equipment pose practical and environmental problems.

JP-A-58-120703 proposes shortening the residence time of the ribbon on the wheel surface by adjusting the speed of the cooling wheel as a means of embrittlement without heat treatment. This allows the ribbon to leave the wheel while still hot, allowing the ribbon to anneal itself and become brittle before entering the fragmentation device.

However, since the ribbon embrittled by this method generally has crystals present at least partially, there is a risk that the excellent properties characteristic of non-quality materials may be lost.

(Problems to be Solved by the Invention) The present invention allows an as-cast amorphous alloy ribbon produced by a melt quenching method to be easily crushed while maintaining its amorphous state. The object of the present invention is to provide a method for easily producing amorphous alloy powder without heat treatment by pulverizing it with an ordinary pulverizer such as a ball mill that does not have a large destructive force.

(Means for Solving the Problems) The present invention provides the following steps in order to make it easier to crush an as-cast amorphous alloy ribbon (hereinafter abbreviated as amorphous ribbon) produced by a melt quenching method. It is characterized by producing a thick amorphous ribbon and pulverizing it directly, that is, omitting the embrittlement treatment, using a pulverizer. The thickness of the amorphous ribbon material used in the present invention is 60μ
m or more, preferably 100 μm or more and 150 μm or less.

FIG. 5 shows an example of the dependence of the powder yield on the thickness of the amorphous ribbon. The powder production conditions were as follows: an amorphous alloy ribbon with an alloy composition of Fe _80.5 Si _6.5 B ₁₂ C ₁ (at%),
The pieces were cut in advance with a steel cutter about 50 mm in diameter, and about 1 kg of this section was inserted into a roulette mill with an internal capacity of 1 liter together with a 20 mm diameter stainless steel ball, and the pieces were crushed by rotating at high speed. The operating time was 15 minutes. The sieves used were 36 mesh (420 μm) and 100 mesh (149 μm).

The yield of the produced amorphous powder slightly increases when the thickness of the amorphous alloy ribbon increases from 40 μm to 50 μm.
The plate thickness increases significantly from around 60 μm. Furthermore, when the thickness of the plate was 100 μm or more, almost the entire amount could be recovered as powder. For this reason, in the method of manufacturing the amorphous alloy powder in the present invention, it is necessary to have a plate thickness of 60 μm or more. Advantageously, 100μ
It is clear that m or more is preferable.

A method for producing amorphous ribbon with a large thickness is disclosed in Japanese Patent Application Laid-open No. 108144/1983 and Japanese Patent Application Laid-open No. 61-1982, which use a multi-slit nozzle as illustrated in FIG. 2a.
There is a method described in Japanese Patent No. 33740, or a method using a nozzle illustrated in FIG. 2b or c. In this case, in order to increase the plate thickness, the length of each nozzle (measured in the direction of substrate movement) may be increased.

FIG. 2 illustrates the type and shape of a nozzle for producing an amorphous ribbon having a thickness of 60 μm or more, which is the raw material for the amorphous powder of the present invention. FIG. 2a is an example of multiple slits. By setting the slit spacing d to 4 mm or less, an integrated thick amorphous ribbon can be obtained. Further increases in board thickness are possible by increasing the multiplicity and decreasing the speed of the cooling substrate. When a triple nozzle with a width of 0.4 mm is used and the peripheral speed of the roll is 18 m/s, the thickness of the ribbon is approximately 80 μm. Nozzles b and c are also used to produce thick amorphous ribbons. In cases b and c, the plate thickness depends on the length of the nozzle in the moving direction of the cooling substrate and the speed of the substrate.

In the present invention, a thick amorphous ribbon serving as a raw material is produced by jetting molten alloy onto the outer peripheral surface of a metal roll serving as a cooling substrate through the above-mentioned nozzle and rapidly cooling it. The maximum thickness of amorphous alloys currently obtained by these methods is about 150 μm. Amorphous ribbons thicker than 60 μm retain the characteristics characteristic of amorphous materials, such as high hardness, strong tensile strength, soft magnetism, and high corrosion resistance, but are less mechanically resistant than thinner amorphous materials of 20 to 40 μm. It has a fragile nature. It can be confirmed by X-ray diffraction that this is not due to crystallization. The reason why thick amorphous alloys are brittle is due to their atomic arrangement, also known as glass metals. Normal thin amorphous material
The reason why it does not break when bent 180° is because it is thin (or thin). This is the same phenomenon as glass fiber being flexible while plate glass is brittle.

Amorphous ribbons with a large thickness can be passed through the pulverization process as they are, but it may be inconvenient if they remain long. In such cases, a preliminary breaking step (cutting off short sections) can be provided. In this case, it is not necessary to use a hammer mill or knife mill with a strong crushing force as disclosed in JP-A-58-12703. In the present invention, for example, hard alloys,
Alternatively, by applying shearing force to the amorphous ribbon with a ceramic cutter, it can be easily broken.

It is efficient to adopt the following method in order to omit the preliminary pulverization step and carry out the entire process from casting to pulverization in an integrated process. Specifically, this is a casting method using a grooved roll as disclosed in JP-A-59-157322 as a cooling base. As shown in FIG. 3, the grooved roll has V-shaped grooves cut in a direction perpendicular to the direction of movement of the cooling body.
Since the ribbon is cut at the groove position, the breaking process can be omitted. Therefore, the steps from casting to pulverization can be carried out in a consistent process as illustrated in FIG.

Next, specific embodiments for carrying out the present invention will be described. First, the outline of the device used in the present invention will be explained in the first section.
As shown in the figure.

A melting section for melting raw materials includes a heating device 1 and a crucible 2 for holding molten metal 3. A nozzle 4 for spouting molten metal is provided at the bottom of the crucible, and is placed opposite a cooling substrate 5 (generally a metal roll).

The shape of the nozzle can take various forms, but in the present invention, as shown in FIG. Thus, a thin ribbon with a large thickness can be manufactured.

However, what is important in the present invention is not the shape of the nozzle, but that the amorphous ribbon formed by casting and before pulverization has a thickness of 60 μm or more. For this purpose, in addition to using a special nozzle as shown in FIG. 2, embodiments of the present invention include reducing the peripheral speed of the roll. However, extremely lowering the circumferential speed of the roll is not preferable from the viewpoint of productivity.

The amorphous ribbon 6 with a thickness of 60 μm or more is rolled up as shown in Fig. 1a without undergoing any embrittlement treatment such as heat treatment, and then directly or as necessary, as shown in Fig. 1b. , and is sent to a powder forming device 11 via a simple breaking device 10 and is pulverized.

When the grooved roll shown in FIG. 3 is used as a cooling substrate, the amorphous flakes are directly fed into the powder forming device 11 without going through a breaking device as shown in FIG. 4, and are pulverized there.

Suitable powder forming apparatuses include commonly used ball mills, roulette mills, vibration mills, rod mills, etc., but are not limited to these.

When the particle size of the powder is required, a classifier is installed following the crusher and the particle size is separated using this device.

The composition of the amorphous powder produced by the method of the present invention is a metal-semimetal alloy, and the metals include Fe, Co,
The main components are Ni, Cr, Mo, V, etc., and the semimetal contains one or more of B, C, Si, P, and Ge. The metal content is 70-90 (at%), and the metalloid content is 70-90 (at%).
Contains 30-10 (at%).

The amorphous powder produced by the method of the present invention is a raw material for magnetic polishing, magnetic clutches, powder cores, brake shoes, magnetic shields, electromagnetic shields, composite reinforcements, (magnetic) filters, and powder compacts. It can be used for etc. Depending on the application, it may be more effective to use it coated with metal plating such as Cu, Sn, Zn, or Ni, or with polymeric material or rubber.

(Example) Next, an example will be given and explained.

Example 1 An amorphous alloy ribbon whose alloy composition is Fe _80.5 Si _6.5 B ₁₂ C ₁ (at%) was passed through a multiple nozzle (triple) of the type shown in Figure 2 a.
Manufactured using. The size of the nozzle used is l = 50
mm, w=0.4mm, d=1mm, roll made of Cu alloy,
The circumferential speed was 18 m/s and the ejection pressure was 0.22 Kg/cm ² . The formed ribbon had a thickness of 65 μm and a width of 50 mm, and X-ray diffraction results showed a halo pattern characteristic of amorphous materials.

This amorphous thin strip is cut in advance with a steel cutter to a length of about 50 mm, and about 1 kg of this cut piece is placed in a vibrating mill with an internal volume of 2 and an Al ₂ O ₃ of about 8 mmφ.
Amorphous powder was produced by charging the powder together with the balls and vibrating it. The particle size of the amorphous powder taken out after 30 minutes of operation time was 34.0% by weight of 420 μm or more;
53.5% had a diameter of 420 to 149 μm, and 12.5% had a diameter of 149 μm or less. The results of X-ray diffraction of the obtained powder showed that it was amorphous. By pulverizing a thick amorphous ribbon in this manner, it was possible to easily produce amorphous alloy powder without the need for embrittlement treatment by heat treatment.

Example 2 An amorphous ribbon having an alloy component of Fe ₇₉ si ₈ B ₁₃ (at%) was produced in the same manner as in Example 1. However, a 5-fold nozzle is used, and the slit width w, the interval d,
The lengths l were 0.4 mm, 1 mm, and 50 mm, respectively.
The fabricated ribbon had a thickness of 105 μm and a width of 50 mm, and as a result of X-ray diffraction, it was confirmed that it was in an amorphous state.

After cutting this thick ribbon into lengths of approximately 100 mm, the sections were placed in a roulette mill with an internal volume of 1 kg.
It was charged together with a 20mmφ stainless steel ball and pulverized by rotating at high speed. The operating time was 15 minutes. The particle size distribution of the produced amorphous powder was 420μ by weight.
33.5% is over m, 41.2% is between 420 and 149μm, and 149μm
The following were 25.3%.

Example 3 A section of an amorphous ribbon having an alloy composition of Fe ₇₀ Co ₁₀ MO ₄ B ₁₂ C ₄ (at%) was produced using a grooved roll shown in FIG. The distance between the grooves is 50 mm, the width of the groove is 1 mm, and the depth is 1
mm V-shape. The nozzle used was a diagonally shaped nozzle shown in Fig. 2. Dimensions are h=4mm, w=1mm,
It is a parallelogram opening with d=0.7mm and tilted at 45°.

The produced thin pieces have a width and length of 50 mm and a thickness of
It was 70μm. X-ray diffraction results showed that it was amorphous. Approximately 1 kg of this flake was pulverized using the roulette mill used in Example 2 for approximately 20 minutes. The particle size distribution of the produced amorphous powder was 21.2% by weight of 420 μm or more, and 420-149 μm.
33.3%, and 45.5% were 149 μm or less.

(Effects of the Invention) As explained above, by employing the method of the present invention, a powder of a specific crystalline alloy can be easily produced by a pulverization method even if the heat treatment step is omitted. Furthermore, since the method of the present invention uses thick materials as raw materials, it has higher productivity than conventional methods that use thin materials (20 to 40 μm) as raw materials. Furthermore, if a grooved roll is used as a cooling roll, a preliminary crushing or cutting process can be omitted, which is of great industrial merit.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of an apparatus for carrying out the present invention, in which a shows a case in which amorphous alloy powder is produced by a direct powder forming device, and a shows a case in which amorphous alloy powder is pulverized via a simple breaking device. be. Figure 2 shows examples of nozzles for producing thick amorphous ribbons or flakes, which are the raw material for the amorphous powder of the present invention, (a) multiple nozzles, (b) comb-shaped nozzles, (c) It is a diagonal comb-shaped nozzle. FIG. 3 is an overall view (a) and a partially enlarged view (b) of a grooved roll which is a cooling substrate used in the present invention to produce amorphous flakes. FIG. 4 is a drawing showing an example of an integrated process in which a thick amorphous flake is directly produced using the grooved roll of the present invention, and then the flake is subjected to a crusher to form a powder.
FIG. 5 is a diagram showing the influence of the thickness of the amorphous alloy ribbon on the powder yield after the pulverization process.

Claims (1)

[Claims] 1. A method for producing an amorphous alloy powder, which comprises forming an amorphous ribbon of a metal-metalloid alloy by a melt quenching method, and further pulverizing the ribbon. Plate thickness
A method for producing an amorphous alloy powder having a diameter of 60 μm or more and being as cast. 2. The method for producing an amorphous alloy powder according to claim 1, wherein the thickness of the amorphous ribbon to be crushed is 100 μm or more. 3. Production of amorphous alloy powder according to claim 1, characterized in that the breaking step is omitted by directly producing thin pieces of amorphous ribbon using a grooved roll on a cooling substrate. Method.