JPS61204305A - Production of amorphous alloy powder - Google Patents

Abstract

PURPOSE:To produce stably amorphous powder having irregular shapes by dropping the melt of an alloy to be made amorphous, blowing high-velocity fluid thereto pulverize the molten metal in a suction pipe having an adequate differential pressure and solidifying quickly the powder. CONSTITUTION:The suction pipe 4 is disposed to around the part for pulverizing the molten metal to suck the molten metal by the pressure difference of 20-200mm H2O and a powder receiving body 5 is disposed right under the above-mentioned suction pipe 4 in a method for producing the amorphous alloy powder by dropping the melt of the alloy to be made amorphous from the fine hole of a crucible 2, blowing water at a high speed thereto from a spraying nozzle 3 to pulverize the molten metal in a spraying tank 1 and cooling quicly the molten metal to solidify. The pulverized alloy powder is forcibly pushed out downward by the evacuation effect of the suction pipe 4 by which the shearing force of the high-velocity water is strongly acted on the powder and the powder shapes are made irredular; at the same time the vapor film formed around the powder is destructed. The cooling rate of the powder is thus considerably increased and the alloy powder is made thoroughly amorphous.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing amorphous alloy powder by spraying a high-velocity liquid onto a flowing molten alloy.

[Prior art]

Conventionally, amorphous alloys have been manufactured by various methods depending on their shape. For example, when producing thin flakes of amorphous alloys, the gun method, piston/anvil method, torsion/catapult method, etc. are used. In addition, when manufacturing thin strips continuously, centrifugation method is used.

Single roll method, double roll method, etc. are used. Furthermore, when producing fine wires, methods such as water spinning method and one-rotation fluid spinning method are used. However, the amorphous alloys obtained by these methods have a specific shape, 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, cavity blowing method, single rotation injection method,
The atomization method is known.

However, this method does not provide sufficient cooling speed.

Only fine particles become amorphous, resulting in poor yield, and the degree of amorphization is non-uniform.

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 utilize 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 high-speed liquid against the molten metal flow, and the processes leading to solidification and cooling after pulverization. In particular, the processes leading to solidification and cooling are closely related to the physical properties of the molten metal, and the shape of the powder is affected by viscosity, surface tension, etc. 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.

[Technical problem to be solved by the invention] The present invention was made based on this knowledge, and the powder after molten metal powder is sucked to destroy the vapor film around the powder and increase the cooling rate.

The purpose of this is to stably and efficiently obtain a powder that is irregularly shaped to the extent that it can be compacted and is completely amorphous.

[Means to solve technical problems]

That is, in this invention, a molten metal of an alloy that becomes amorphous is caused to flow down through pores and a high-velocity liquid is sprayed.

In the method of manufacturing amorphous alloy powder by pulverizing molten metal and rapidly solidifying it, a suction pipe is placed around the point where the molten metal is pulverized, and suction is carried out at a pressure difference of 20 mH, O to 200 mH, O. , further characterized in that the powder body is placed below the suction tube.

The present invention will be described below with reference to illustrative embodiments. The drawing shows an example of an amorphous alloy manufacturing apparatus. This device is
Place the crucible 2 on the 'rJxs tank 1, and install the spray nozzle 3 below the crucible 2. A suction pipe 4 and a powder body 5 are arranged in this order, and an overflow pipe 6 attached to the spray tank 1 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. This alloy mainly consists of transition metal elements and about 15 to 35 atoms of metalloid elements (B
, C, 8i, P, Ge, etc.) and transition metal-transition metal systems, transition metal-metal systems, metal-
Examples include metal-based and metal-rare earth intermetallic compound alloy types.

The spray nozzle 3 is, for example, an annular ring nozzle that spouts high-speed liquid such as water, and focuses the high-speed liquid at point a. The intersection angle of this high-speed liquid is the spray nozzle opening diameter,
High speed of liquid.

It varies depending on the diameter and length of the suction tube 4, but it is 30" to 100".
″′ is preferable.Also, the speed of high-speed liquid is .

It depends on the spray pressure P, preferably 80 to 9 f/♂ or more.

Furthermore, the suction tube 4 is provided so as to surround point a.

It is located above the overflow pipe 6.

The smaller the diameter of this suction tube 4, the faster the cooling rate can be achieved, but if the diameter is too small, the powder after pulverization will adhere to the inner wall of the suction tube 4, making it difficult to continue pulverization. It is preferably about 0.2 to 3.0 times the nozzle opening diameter.
Also, if the length is too short, the suction effect will be small, so
0 (need to be 1 m or more.Although the shape may be any shape, a cylindrical one is preferable. Furthermore, the pressure difference between the upper chamber 8 and lower chamber 9 of the spray tank 1 is 20 m or more.
18H,O to 200111H,O preferably 4Offi
It should be 1H,O to 200H,O. The reason for this is that if the pressure difference is too small, the suction effect will be too small and the desired purpose cannot be achieved, but if the pressure difference is too large, it will be difficult to contact the liquid and the powder, making it impossible to obtain the desired cooling rate, resulting in complete amorphous formation. This is because it becomes difficult to do so.

Further, the powder volume body 5 is provided directly below the suction pipe 4 and above the overflow pipe 6. The amount of powder is not particularly limited depending on the structure of the body 5, and it may be integrated with the suction tube 4 or separated.

[Action and effect of the invention]

According to the method of the present invention, the molten metal flows down from the pores of the crucible 2, and the flowing molten metal is pulverized by the high-speed liquid jetted from the spray nozzle 3. At this time, the powdered alloy powder is transferred to the suction tube 4
It is forcibly pushed downward by the decompression effect. Because of this)
The high-speed liquid ′ strongly acts on the alloy powder and makes it irregular. Furthermore, it destroys the vapor film generated around the powder and significantly increases the cooling rate of the powder. Then, the powder is applied to the powder receiver body 5, and then captured in the spray tank 1 or the discharge tank 7, and then the adhering fluid is removed to obtain an amorphous alloy powder.

In this case, since the powder receiver is first applied to the body 5, the spray tank 1
Fluctuations in the pressure difference between the upper and lower chambers are prevented by suppressing fluctuations in the water surface within the chamber, and as a result, a desired pressure difference can always be obtained and powdering can be performed stably.

〔Example〕

Next, examples of the present invention will be described.

Example 1 peso atom%, P13 atom%, C7 atom g.

5 kg of an alloy of the same composition was melted and allowed to flow down from a nozzle at a molten metal temperature of 1400°C. A spray pressure of 125 kg is applied to this flowing molten metal.
Water was ejected at a flow rate of 290 rpm and a spray intersection angle of 65°, and the particles were further suctioned with a suction tube, and the bone particles were applied to the body to obtain an amorphous alloy powder (Melon 1). In this case, the suction tube has an inner diameter of 5
Qmψ, length 4QQm, differential pressure between upper and lower chambers 11Qs
sH,Q.

The particle size distribution of the amorphous alloy powder obtained in this way was investigated, and the results are shown in Table 1.
Amorphous alloy powder (Fo, 2) was produced under the same conditions without using a powder receiver, and its particle size distribution was investigated. The results are also listed in Table 1.

Next, among the powders (fLl) according to the present invention, powders of +100 mesh, -100 to +300 mesh, and -350 mesh were subjected to X-ray diffraction to determine whether or not they had become amorphous. The results are shown in Figure 2 @) (+100 mesh) and Figure 2 (b) (-350 mesh). Furthermore, the conventional powder (Mu2) 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
(-350 mesh) and the same figure (b) (-350 mesh). From FIG. 2 and FIG. 3, it can be seen that in the case of the present invention, no crystalline diffraction pattern is observed, and the diffraction pattern is broad and amorphous. Regarding the -100 to +350 Messier, although not shown, similar X-ray diffraction revealed that the one of the present invention was amorphous, while the conventional one was crystalline.

Next, the degree of amorphization of each amorphous alloy powder was determined 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.

Also, each amorphous alloy powder (g 1 s fO,' 2 )
The shape of the powder was examined using a microscope, and its schematic diagrams are shown in FIG. 4 (A) (invention powder) and FIG. 4 (B) (conventional powder). It can be seen from FIG. 4 that the alloy powder of the present invention has an irregular shape.

Next, Table 3 shows the results of examining the apparent density k (A, D,) and fluidity (F, 几,) of the powder according to the present invention (No. 1) and the conventional powder (No. 2). Shown below.

From Table 3, it can be seen that the powder of the present invention has a significantly lower apparent density than the conventional powder, poor flowability, and is significantly irregular compared to the conventional powder.

Example 2 Alloy 5 of 75 atoms of iron, 5io atoms, and 15 atoms of B
kg was dissolved 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, 8115 atoms of iron, and 10 atoms of B
kg was dissolved to produce an amorphous alloy powder under the same conditions as in Example 1. Table 5 shows the degree of amorphization.

Table 5 Example 4 9 was dissolved in alloy 4.0 of 80 atoms of iron and 20 atoms of boron, the melt temperature was 1400°C, and the spray pressure was 100 Icg/
an”, water flow rate 250 rpm, spray intersection angle 40 degrees,
The suction tube had an inner diameter of 40 mm, a length of 5 QQIII, and a pressure difference between the upper and lower chambers of 70 mm to prepare powder. The degree of amorphization is shown in Table 6.

ig6 Table Example 5 9 was dissolved in alloy 5.0 of 40 at% iron, 40 at% nickel, and 20 atms boron, molten metal temperature 1400°C, spray pressure 110#/crrL'', water flow rate 260 rpm/min.
, the spray intersection angle is 50 degrees, and the suction pipe has an inner diameter of 50 m! 1φ, length 5
001 m), pressure difference between upper and lower chain 85 wbH,
A powder was prepared using 0. Table 7 shows the degree of amorphization.

Table 7 Example 6 68 atoms of iron, 10 atoms of chromium, 2 atoms of molybdenum *
, 13 atom % of 'J' and 7 atom of carbon 5. OIcg
melted, molten metal temperature 1400℃, spray pressure 1201cy
/crn', water flow t270 min/min, spray intersection angle 68
The suction tube had an inner diameter of 50 mm, a length of 450 mm, and a pressure difference between the upper and lower chambers of 100 mH. Table 8 shows the degree of amorphization.

Table 8 As explained above, according to the present invention, a suction pipe is installed to increase the cooling rate.

A completely amorphous alloy powder can be obtained, and the alloy powder can be made into an irregular shape. For this reason, this alloy powder can be compacted, formed between rolls, extruded, etc. without using a binder. For example, it can be used to create magnetic materials with complex shapes, highly corrosion-resistant materials, etc. that cannot be produced using conventional amorphous alloys. It has remarkable effects that can be used for new applications that were previously unavailable. Further, by providing a powder receiver with a body, powder can be produced stably. Moreover, the simple structure of adding a suction tube and a powder receiver to the conventional device facilitates efficient manufacturing.

Note that the method of the present invention is used for producing ultra-quenched alloy powder;
You can also 'ru'.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of an apparatus for manufacturing an amorphous alloy powder according to the method of the present invention, and FIG. Figure 3) and Figure (b) are diagrams showing the OXm diffraction results of conventional alloy powder, Figure 4 f1) is a schematic diagram of the alloy powder of the present invention,
Figure (b) is a schematic diagram of a conventional alloy powder. 1... Spray tank, 2... Crucible, 3... Spray nozzle, 4... Suction pipe, 5... Powder receiver body, 6...
Overflow pipe% 2...Discharge tank. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 (A) (B) e26 Figure 3 (A) (B) t. Figure 4

Claims (1)

[Claims] The area around the area where the molten metal is pulverized in a method of producing amorphous alloy powder by flowing the molten alloy that is to be amorphous down through pores and spraying a high-speed liquid to pulverize the molten metal and rapidly solidify it. Place the suction tube to 20mmH_2O to 200
A method for producing amorphous alloy powder, which comprises suctioning with a pressure difference of mmH_2O and arranging a powder receiver below the suction tube.