JPH04193902A - Device for manufacturing metal powder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an apparatus for producing metal powder by injecting molten metal into a swirling cooling liquid layer.

(Prior art) Rapidly solidified metal powder has fine crystal grains and can contain supersaturated alloying elements. It has excellent material properties that no other material has, and is attracting attention as a material for mechanical parts.

A preferred method for producing the cold solidified metal powder is a rotating drum method. This method, as shown in Figure 3,
A method in which a cooling liquid layer 62 is formed on the inner peripheral surface of a rotating cooling drum 61 by the action of centrifugal force, and molten metal is injected into the cooling liquid layer 62 to obtain finely divided metal powder. It is. In the figure, 63 is an injection crucible serving as a molten metal injection means, and a high frequency coil 64 for heating is attached to the outer peripheral surface of the crucible, and an injection nozzle 65 is provided on the lower side wall of the crucible.

The molten metal 66 in the crucible 63 is transferred to the nozzle 6 by injecting an inert gas 67 into the crucible 63 under pressure.
It is ejected from 5.

When a certain amount of metal powder accumulates in the cooling drum 61, the rotation of the cooling drum 61 is stopped, the metal powder is collected together with the cooling liquid, and the metal powder is removed and dried.

(Problems to be Solved by the Invention) However, the rotating drum method requires so-called hatch-type operation, which has poor productivity and also requires stopping the injection of molten metal during powder recovery, which causes the problem that the nozzle is easily clogged. There is. In addition, in order to keep the cooling temperature constant, the temperature must be controlled by discharging and supplying the cooling liquid from the liquid surface of the cooling liquid layer, but in this case, the liquid level is disturbed and the powder particle size and quality may vary. There was a problem with livability.

The present invention was devised in view of such problems, and an object of the present invention is to provide a metal powder manufacturing apparatus that enables continuous production and that can obtain powder of stable quality.

(Means for Solving the Problems) The manufacturing apparatus of the present invention, which has been made to solve the above problems, is provided with a cooling liquid jetting pipe 7 for jetting and supplying cooling liquid from a tangential direction along the inner peripheral surface. a cooling cylinder 1, and a molten metal injection means 2 for injecting molten metal onto a cooling liquid layer 21 formed on the inner circumferential surface of the cylinder l by the cooling liquid jetted from the cooling liquid jetting pipe 7. and the coolant jet pipe 7
and cooling liquid supply means 3 for supplying cooling liquid to the
A ring 6 for adjusting the layer thickness of the cooling liquid layer 21 is attached to the lower inner circumferential surface of the cylinder 1, and the discharge port 8 of the cooling liquid jet pipe 7 is located from the center position between the upper end of the cylinder and the upper end of the ring. The structure of the invention is that the ring is opened up to the upper end of the ring.

(Function) The coolant jetted out along the inner peripheral surface of the cylinder 1 flows down while swirling along the inner peripheral surface of the cylinder, overflows the layer thickness adjustment ring 6, and flows downward. At this time, since the discharge port 8 of the coolant jet pipe 7 opens between the center position between the upper end of the cylinder and the upper end of the ring and the upper end of the ring, the distance from the discharge port 8 to the layer thickness adjustment ring 6 is becomes shorter,
A decrease in the thickness of the cooling liquid layer 21 due to an increase in the flow rate of the cooling liquid is suppressed, and a cooling liquid layer 21 having a substantially constant thickness and a constant swirling speed is obtained. Note that above the discharge port 8, the coolant is lifted by the action of centrifugal force, and a coolant layer having a constant thickness almost the same as that below is formed.

When molten metal is injected and supplied from the inner peripheral surface of the cooling liquid layer 21, the molten metal is divided by the swirling flow and rapidly solidified into powder.

At this time, since the cooling liquid layer 21 is always formed by newly supplied cooling liquid, a constant temperature can be easily maintained. Therefore, in order to control the temperature, the cooling liquid is discharged from the liquid surface.
There is no need to supply the liquid, and the liquid level remains stable without any disturbance. Therefore, the molten metal injected into the cooling liquid layer 21 is always injected into the cooling liquid layer 21 under a constant condition.
Since it is divided and cooled and solidified at a constant temperature, the quality of the metal powder is stabilized.

Since the metal powder in the cooling liquid layer 21 flows down while swirling together with the cooling liquid and is discharged from the lower end of the cylinder 1, continuous production of metal powder becomes possible.

(Example) Figure 1 shows a metal powder manufacturing apparatus according to an example.
A cooling cylinder 1 for forming a cooling liquid layer 21 on the inner peripheral surface, an injection crucible 2 which is a means for injecting and supplying molten metal 22 to the cooling liquid layer 21, and a cooling liquid to the cylinder 1. A pump 3 is provided as a means for supplying the water.

The cylinder l has a cylindrical shape, and a lid 5 having an appropriately sized opening 4 in the center is attached to the upper end thereof. A ring 6 for adjusting the layer thickness of the cooling liquid layer 21 is attached to the inner circumferential surface of the intermediate portion with bolts so as to be detachable and replaceable. A discharge port 8 of the coolant jet pipe 7 opens between the center position of the upper end of the cylinder 1 and the upper end of the layer thickness adjustment ring 6 and the upper end position of the ring 6. The axial direction is set in a tangential direction slightly obliquely downward to the inner peripheral surface of the cylinder. A cylindrical net 9 for draining liquid is connected to the lower end of the cylinder 1, and a funnel 10 for collecting powder is attached to the lower end. A cover 11 is provided around the net body 9.

FIG. 2 shows the discharge port 8 of the coolant jet pipe 7 from the upper end of the cylinder 1.
The vertical distance to the center is A: Loan, B: 25 kaku,
C: Shows the results of measuring the flow velocity of the coolant layer at each position from the upper end of the cylinder 1 to the upper end of the layer thickness adjustment ring 6 with the setting set to 45 mm. In addition, water is used as the cooling liquid, the inner diameter of the cylinder is φ100 ceramic, the distance from the top of the cylinder to the top of the ring is 50mm, the inner diameter of the ring is φ45mm, and the discharge port is 4 mm.
It is 11 mm.

According to the figure, when the discharge ports 8 were provided at positions B and C, there was almost no change in the flow velocity, and the inner diameter of the coolant layer 21 was approximately 45 mm, which was stable.

On the other hand, in the case where the discharge port 8 is provided at the A position, the flow velocity decreases as it goes downward, and the inner surface shape of the coolant layer 21 also gradually expands in diameter from the A position to the upper part of the C position. The layer thickness became thinner and a stable layer thickness could not be obtained.

The coolant jet pipe 7 is connected via a pump 3 to a tank 12 . Further, the bottom of the cover 11 is piped to a tank 12, and the coolant collected by the cover 11 is returned to the tank 12 and used for circulation. The tank 12 is provided with a cooling liquid supply pipe for replenishment (not shown), and a cooler may be appropriately interposed within the tank or in the middle of the circulation path. As a coolant, - water is used for boat fishing.

An injection crucible 2 serving as a molten metal supply means is provided above the lid 5, and a heating coil 1 is installed on the outer periphery of the crucible 2.
4 is wound and formed, and a nozzle hole 15 is opened at the bottom thereof. Inert gas such as Ar or N2 and molten metal are pumped into the injection crucible 2, and the molten metal 22 in the crucible 2 is injected from the nozzle hole 15.

To carry out the present invention, first, the pump 3 is operated, and the cooling liquid layer 21 flows down the inner peripheral surface of the cylinder 1 while rotating at high speed.
form.

Next, Ar gas or the like is pumped into the injection crucible 2 provided at the top of the cylinder 1, and the molten metal 22 in the crucible 2 is transferred to the nozzle hole 1.
5, the coolant is injected onto the inner surface of the cooling liquid layer 21, divided, rapidly solidified, and powdered.

The metal powder flows into the cylinder 1 together with the cooling liquid forming the cooling liquid layer 21.
It is discharged from the bottom opening. Most of the coolant is separated and discharged by the net 9 due to the centrifugal force of the coolant itself before flowing down into the funnel 10. The metal powder containing the cooling liquid discharged from the funnel 10 is deliquified by an appropriate dehydrating machine such as a centrifuge, and dried to become a product powder.

(Effects of the Invention) As explained above, the metal powder manufacturing apparatus of the present invention has a cooling liquid jet pipe between the center position of the upper end of the cylinder and the upper end of the layer thickness adjustment ring of the cooling liquid layer and the upper end of the ring. The cooling liquid is spouted from the discharge port along the inner circumferential surface of the cylinder to form a cooling liquid layer that flows downward while swirling along the inner circumferential surface of the cylinder. The inner diameter and flow rate of the coolant layer into which it is injected are stabilized, and the temperature of the coolant layer is easily maintained uniformly. Since molten metal is injected into the cooling liquid layer from the molten metal injection supply means, rapidly solidified powder of constant quality is continuously produced, and productivity is high (no clogging occurs in the injection nozzle).

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional explanatory diagram of the main part of the metal powder manufacturing apparatus according to the embodiment, and Fig. 2 shows the distance from the upper end of the cylinder and the flow velocity of the coolant layer when the outlet opening position of the coolant jet pipe is different. FIG. 3 is a sectional view of a main part of a conventional metal powder manufacturing apparatus. 1-Cylinder for cooling, 2-Injection crucible (molten metal injection means)
, 3-pump (coolant supply means), 6-layer thickness adjustment ring, 7-coolant jet pipe, 8-discharge port, 21-coolant layer.

Claims (1)

[Claims] (1) A cooling cylinder (
1), and molten metal injection for injecting molten metal onto the cooling liquid layer (21) formed on the inner peripheral surface of the cylinder (1) by the cooling liquid jetted from the cooling liquid jetting pipe (7). means (2) and a coolant supply means (3) for supplying coolant to the coolant jet pipe (7);
A ring (6) for adjusting the layer thickness of the coolant layer (21) is attached to the lower inner peripheral surface of the coolant jet pipe (7).
8) An apparatus for producing metal powder, characterized in that the opening is opened between a central position between the upper end of the cylinder and the upper end of the ring and the upper end of the ring.