JPS6024303A - Production of amorphous alloy powder - Google Patents

Abstract

PURPOSE:To produce efficiently alloy powder which has irregular shapes and is made thoroughly amorphous by letting a molten alloy flow down through a fine hole, blowing high-velocity fluid to the molten alloy to pulverize the same and cooling quickly and solidifying the pulverized alloy by allowing to collide the powder against a cooling block. CONSTITUTION:The molten alloy to be made amorphous in a crucible 2 is let to flow down through a fine hole in the lower part of the crucible into a spraying tank 1 where a high-velocity fluid is ejected from a spraying nozzle 3 is blown to pulverize the molten alloy. The pulverized powder is allowed to collide against a cooling body 4 which is provided right under the pulverizing point (a) for the molten alloy and has a circular conical shape at the upper part to solidify quickly the powder. The solidified powder is taken out of a discharge tank 7 through an overflow pipe 6 in the form of the amoprhous alloy powder. A circular cylindrical wall 5 for preventing scattering is further provided around a cooling block 4 to prevent scattering of the formed powder and to accelerate the quick cooling by the additional suction of the powder. The amorphous alloy powder is thus efficiently obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing amorphous alloy powder by blowing and impregnating a flowing molten alloy with a flowing fluid.

Conventionally, amorphous alloys have been manufactured by various methods depending on their shape. For example, when manufacturing amorphous alloys in the form of flakes, the Gunn method, the piston-Anovil method, the torsion-Katanogult method, etc. are used. In addition, when manufacturing ribbons continuously, a centrifugal method, a single roll method, a twin roll method, etc. are used. Furthermore, when producing fine wires, methods such as water spinning and rotating liquid spinning are used. However, the amorphous alloys obtained by these methods have limited shapes, and it is very difficult to manufacture parts with arbitrary shapes.

On the other hand, a powder metallurgy method in which powder is compacted using a press or the like is known as a method for manufacturing parts with complex shapes. In addition, methods for producing amorphous alloy powder include spray method, cavitation method, injection method in rotating liquid,
The atomization method is known.

However, in this method, the cooling speed is not sufficient, only fine particles become amorphous, the yield is poor, and the degree of amorphization is uneven.

Moreover, since the shape of the obtained amorphous alloy powder is spherical or flake-like, there is little entanglement between the powders even when compacted, making it difficult to manufacture semi-finished materials, parts, etc. without using a binder. I can't. Therefore, it is difficult to industrially use powders obtained by these methods in powder metallurgy.

As a result of repeated research to solve this problem, the inventor found that
The following findings were obtained.

The shape of the powder obtained by pulverizing molten metal is greatly influenced by the pulverization characteristics determined by the shearing force of the still-velocating fluid on the molten metal, and the processes leading to solidification and cooling after pulverization. In particular, the processes leading up to solidification and cooling are closely related to the physical properties of molten forging, and the shape of the powder is affected by viscous surface tension and other factors during the cooling process. Moreover, the relative factors between these physical properties and the cooling rate have a great influence on the amorphization of the powder.

The present invention was made based on this knowledge, and its purpose is to destroy the vapor film around the powder by applying the powder after powdering in a hot water bath to a cooling block, and to further reduce the cooling rate. The object of the present invention is to provide a method that can efficiently obtain a compactable powder that is completely amorphous and has an irregular powder shape.

That is, the first invention is to flow down the hot water of the alloy to be amorphous through the pores and spray a high-velocity fluid to powder the hot water and rapidly solidify it to produce an amorphous alloy powder. In this method, a cooling block is placed directly below the point where the molten metal is pulverized, and the pulverized particles are applied to the cooling block. Further, the second invention is characterized in that a scattering prevention wall is provided around the cooling block.

The present invention will be explained below with reference to the drawings.

The drawing shows an example of an amorphous alloy manufacturing apparatus.

In this device, a crucible 2 is entirely placed on a spray tank 1, a spray nozzle 3 and a cooling block 4 are placed below the crucible 2,
A scattering prevention wall 5 is provided around the cooling block 4, and an overflow pipe 6 to which a spray tank II/C is attached is connected to a discharge tank 7.

Crucible 2 is for containing the molten alloy that will become amorphous.
Pores are formed at the bottom. As a raw material, this alloy contains about 15 to 35 atoms of a transition metal element (B).
, C, Si+P, Ge & G) 'e added eutectic alloy type and intermetallic compound alloy type such as transition wire mesh-transition metal system, transition metal-metal system, metal-metal system, gold maple-rare earth system, etc. It will be done.

The spray nozzle 3 is currently a ring nozzle that spouts a high-speed fluid (for example, liquid such as water or gas), and is designed to focus the high-speed Mt body at point a. The intersection angle of this high-speed fluid varies depending on the opening diameter of the ejaculation nozzle, the speed of the high-speed fluid, and the size and position of the cooling block 4, but is 30'
-100' is suitable. In addition, the speed of high-speed fluid depends on the spray pressure p, which is 80 kgf/cm for liquid.
2 or more, preferably 6 to 9 f/cnr2 or more in the case of gas.

Further, the cooling block 4 is provided directly below the point P3ra where the molten metal is powdered. The cooling block 4 has a conical upper part, and the molten metal powder is formed on the slope thereof. The angle θ of the top of this cooling block 4
is optional, but is preferably 30-150' in order to allow the powder to flow downward smoothly. The material of the cooling block 4 is preferably steel plated with chrome, and the inside may have a water-cooled structure.

The anti-scattering wall 5 provided around the cooling plate 4 has a cylindrical shape, for example, and has a structure to prevent particles from scattering. If the inner diameter of the scattering prevention wall 5 is too small, it will be difficult to continue granulation. For this reason, it is preferable that the diameter is larger than the diameter of the cooling block 4 by 100 mm.

Thus, in the method of the present invention, the molten metal flows down through the pores of the crucible 2, and the flowing molten metal is pulverized into a madder fluid that is ejected from the spray nozzle 3. At this time, by applying the powdered alloy powder to the cooling block 4, the cooling rate is increased, and the vapor film generated around the powder is destroyed, thereby significantly increasing the cooling rate of the powder. At this time, the scattering prevention wall 5 prevents the powder from scattering. Additionally, the anti-scattering wall 5 additionally has a quenching effect by suctioning the powder.

The powder is then captured in the spray tank 1 or the discharge tank 7,
After a step of removing the attached NdM body, an amorphous alloy powder is obtained.

Next, examples of the present invention will be described.

Example 1 5 kg of an alloy having a composition of 80 atomic % Fe, 13 atomic % P, and 0.7 atomic % was melted and allowed to flow down from a nozzle at a molten metal temperature of 1400°C. Spray pressure 105kli+ on this flowing molten metal
, fi fold 280.4/rrI+n-, water was ejected at a spray intersection angle of 40°, and the amorphous alloy powder (Nllυ was obtained by applying it to a cooling block. In this case, the cooling block had a conical upper part, and the apex angle was The angle θ was set to 120°, and the diameter d was set to 150 mφ.

In addition, the anti-scattering wall around the cooling block has an inner diameter of 200 mm.
It has a cylindrical shape with a diameter of φ and a length of 200 m.

The particle size distribution of the amorphous alloy powder thus obtained was examined, and the results are shown in Table 1. For comparison, an amorphous alloy powder (Number 2) was produced under the same conditions except that a cooling block and anti-scattering wall were used, and its particle size distribution was investigated. The results are also shown in Table 1.

Next, among the powders (Nal) according to the present invention, +100 mesh and -350 mesh were subjected to X-ray diffraction to examine whether or not they had become amorphous. The results are shown in Figure 2 (a) (+1
00 mesh and the same figure (b) (-350 mesh). Furthermore, the conventional powder (Fly 2) was similarly subjected to X-ray diffraction to determine whether it had become amorphous or not. The results are shown in Figure 3 (A) (+100 meters) and Figure 3 (B) (-3
From FIGS. 2 and 3, the crystalline diffraction and
It can be seen that there is no visible turn and it becomes broad, indicating that it has become amorphous.

Next, the degree of amorphization of each amorphous alloy powder was investigated by differential thermal analysis. The results are shown in Table 2.

Table 2 It can be seen from Table 2 that complete amorphization can be achieved by the method of the present invention.

In addition, the shape of each amorphous alloy powder (1, 1@2.) was examined using a microscope, and a schematic diagram thereof is shown in FIG. It can be seen from FIG. 1 that the alloy powder of the present invention has an irregular shape.

Next, the apparent density (A, D) and fluidity (F・R) of the powder according to the present invention (Part 1) and the conventional powder (Taki 2) were investigated, and the results are shown in Table 3. .

Table 3 From the above table, it can be seen that the powder of the present invention has a significantly lower apparent sound intensity than that of the conventional powder, has a poor distribution, and is therefore significantly irregular compared to the conventional powder.O Example 2 Iron Alloy 5 of 75 atoms, 5ilo atoms, B15 atoms
9 was melted to produce an amorphous alloy powder under the same conditions as in Example 1. Table 4 shows the degree of amorphization.

Table 4 Example 3 Alloy 5 of 75 atoms of iron, 15 atoms of 5i, and 10 atoms of B
Ky was dissolved and an amorphous alloy powder was produced under the same conditions as in Example 1. The degree of amorphization is shown in Table 5. Table 5 Example 4 Alloy of 80 atoms of iron and 20 atoms of poron 5. Melt Okg, molten metal temperature 1400℃, spray pressure 9Qkj7/cm
2. Water flow k 260 A/min l QJ (fJ Intersecting angle 30 particles, cooling block diameter 130 mm, apex angle 100 degrees, scattering prevention wall inner diameter 160 a φ) Powder was prepared.The degree of amorphization is shown in Table 6. Shown below.

Table 6 Example 5 40 atoms of iron, 40 atom% of nickel, H? Ron, 20 atomic bags of alloy 3.0~ were melted, the molten metal temperature was 1400℃, the spray pressure was 107kg7cm2. Water flow rate 290 koku/m
1 n *Spray intersection angle 40 degrees, cooling block diameter 150 degrees
6φ, apex angle 90 degrees, inner diameter of scattering prevention wall 1701++1φ
A powder was prepared. Table 7 shows the degree of amorphization.

Table 7 Example 6 Alloy of 68 atoms of iron, 10 atoms of chromium, 2 atoms of molybdenum, 13 atoms of phosphorus, and 7 atoms of carbon 3. Melt Okg, molten metal temperature 1400℃, spray pressure 110kg7c
m2. Water flow 11250 n/min, spray intersection angle 55
The cooling block has a diameter of 180ffllφ.

The powder was prepared with an apex angle of 110 degrees and a scattering prevention wall with an inner diameter of 200 gφ. The degree of amorphization is shown in Table 8. By bumping the entire powder after granulation into a cooling block to increase the cooling rate, it is possible to obtain an amorphous alloy powder as well as to make the alloy powder into an irregular shape. Therefore, this alloy powder can be compacted, formed between rolls, extruded, etc. without using a binder. It has remarkable effects and can be used in new applications that could not be made with high quality alloys.

Moreover, it can be manufactured efficiently with a simple structure in which a conventional device is provided with a cooling block and a scattering prevention wall.

In addition, this method can also be used to produce ultra-quenched alloy powder.

[Brief explanation of drawings]

11 is an explanatory diagram showing an example of an apparatus for producing amorphous alloy powder according to the method of the present invention, FIG. Figure 3 HJ and figure (b) are diagrams showing the X-ray diffraction results of the conventional alloy powder, and Figure 4 (in is a schematic diagram of the alloy powder of the present invention, and figure (b) is a schematic diagram of the conventional metallized powder. Deluru. l...Saki b tank, 2...Rutsu 8i, 3...Uta powder nozzle, 4°°° cooling pro, 5...Scatter prevention wall,
6...O-guno-no-pipe, 7...Discharge tank. Applicant's agent Patent attorney Takeshi Suzue Hikoyori 1 Figure 3 IP 2f! 1 (a) (b) 2θ 2θ 3IP3f! 1 (a) (b) Spear 4 Diagram (a) (b) Procedural amendments Showa 49. May 25, 1949, Director General of the Patent Office Mr. Wakasugi Motoguchi ■, Indication of Case Patent Application No. 131382 No. 1988 2, Invention Name of the method for manufacturing amorphous alloy powder 3, Relationship with the Nagisa case where the amendment is made Patent applicant Nippon Metal Co., Ltd. 4, agent 5, voluntary amendment 7, content of the amendment (1) Liang 10 negative number in the specification 1+1 for 1st line to 2nd line
00 mesh, -350 mesh” is changed to “+100 mesh”
``Mesh, -100 mesh to +350 mesh, and -350 mesh.'' (2) I understand the phrase "I understand." on page 10, line 12. It should be noted that -100 to +350 meshes (although the two meshes are not shown, similar X-ray diffraction revealed that the one of the present invention became amorphous and the conventional one was of the delivered quality.) .

Claims (2)

[Claims] (1) In the method of producing amorphous alloy powder by flowing the molten metal of the alloy to be amorphous down through pores and spraying a high-velocity fluid to powder the molten metal and rapidly solidify the molten metal, the molten metal is powdered. A method for producing an amorphous alloy powder, characterized in that a cooling block is placed directly below the point and the powdered particles are applied thereto. (2) In the method of manufacturing an amorphous alloy powder by flowing the molten metal of the alloy to be amorphous down through pores and spraying a high-velocity fluid to powder the molten metal and rapidly solidify the molten metal, the molten metal is powdered. 1. A method for producing amorphous alloy powder, characterized in that a cooling block is placed directly under the cooling block, a scattering prevention wall is provided on the circumferential surface of the cooling block, and the powdered particles are applied to the cooling block.