JPH07103407B2 - Continuous production method of rapidly solidified metal powder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a metal powder by injecting a molten metal into a swirling moving cooling liquid layer. Up to a method that can be continuously processed.

(Prior Art) Since the rapidly solidified metal powder has fine crystal grains and can contain alloy elements in a supersaturated state, for example, an extruded material formed by rapidly solidified metal powder of aluminum or its alloy is not included in the ingot material. It has excellent material characteristics that do not occur, and is attracting attention as a material for machine parts and the like.

A rotating drum method is a suitable method for producing the rapidly solidified metal powder. According to this method, as shown in FIG. 3, 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 finely divide the cooling liquid layer 62. Is a method of obtaining a rapidly solidified powder. In the figure,
Reference numeral 63 is an injection crucible to which a high-frequency coil 64 for heating is attached, and an injection nozzle 65 is opened on the lower side wall thereof. Molten metal 66 in the crucible 63 is ejected from the nozzle 65 by injecting an inert gas 67 into the crucible 63 under pressure.

Then, when a certain amount of the metal powder in the cooling drum 61 is accumulated, the rotation of the cooling drum 61 is stopped, the metal powder is collected together with the cooling liquid, dehydrated and then dried.

(Problems to be Solved by the Invention) However, in the rotary drum method, so-called batch type drying is performed, which is inferior in productivity, and since the injection of the molten metal must be stopped at the time of powder recovery, there is a problem that the nozzle is likely to be clogged. There is. In addition, the time from pulverization to drying of the molten metal is long, that is, the time the powder is in contact with the cooling liquid is long, the gas content of hydrogen, oxygen, etc. in the powder is increased, and There is a problem that gas defects are likely to occur during heat treatment of the extruded material.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a continuous production method of rapidly solidified metal powder capable of continuous production of metal powder and capable of being rapidly processed from pulverization to drying. .

(Means for Solving the Problem) The manufacturing method of the present invention made to solve the above-mentioned problem is such that the cooling liquid is jetted and supplied along the inner peripheral surface of the cylindrical body 21 and swirled along the inner peripheral surface of the cylindrical body. While forming the cooling liquid layer 31 flowing down, injecting a molten metal from the inner peripheral surface side of the cooling liquid layer 31, to obtain a metal powder by cooling and solidifying by cutting by the cooling liquid layer 31,
The configuration of the present invention is that the metal powder that has flowed down from the cylindrical body 21 together with the cooling liquid is continuously drained and then continuously dried.

(Operation) The cooling liquid jetted and supplied along the inner peripheral surface of the cylindrical body 21 flows down while swirling along the inner peripheral surface of the cylindrical body, and the centrifugal force at the time of swirling causes the cooling liquid layer having a substantially constant inner diameter. Forming 31. When the molten metal is injected and supplied from the inner peripheral surface of the cooling liquid layer 31, the molten metal is divided by the swirling flow and rapidly cooled and solidified into powder.

At this time, since the cooling liquid layer 31 is always formed by the newly supplied cooling liquid, a constant temperature is easily maintained.
Therefore, it is not necessary to discharge and supply the cooling liquid from the liquid surface for temperature control, and the liquid surface is not disturbed and a stable state is maintained. Therefore, the molten metal injected into the cooling liquid layer 31 is constantly injected into the cooling liquid layer 31 under a constant state, is divided, and is cooled and solidified at a constant temperature, so that the quality of the metal powder is stabilized.

The metal powder in the cooling liquid layer 31 flows down while swirling together with the cooling liquid and is discharged from the lower end of the cylindrical body 21, so that continuous production of the metal powder is possible.

Furthermore, since the metal powder discharged together with the cooling liquid is continuously deliquored and subsequently dried, the period of contact with the cooling liquid from pulverization to drying is short, and the absorption of gas components is small.

(Example) FIG. 1 shows the overall configuration of an apparatus for carrying out the present invention. The molten metal sent from the continuous pouring apparatus 1 is a powdering apparatus 2, a continuous dewatering machine 3, and a continuous drying apparatus. The product metal powder is passed through the device 4.

The continuous pouring device 1 includes a main body container 6 formed of a refractory heat insulating material, and the container 6 is provided with a metal melt supply port 8 which can be sealed by a lid 7 so that an inert gas or the like A pressure medium supply pipe 9 and a discharge pipe 10 for the molten metal in the container are provided, and a recess 12 having an induction heating coil 11 is provided at the bottom. The temperature of the molten metal 13 in the container 6 is controlled by the coil 11, and the powdering device 2 is evacuated by the inert gas such as argon gas injected from the pressure medium supply pipe 9 through the discharge pipe 10.
Pumped to. The discharge pipe 10 is kept warm by the formation of a heat insulating layer and an appropriate heat keeping means such as an induction heater.

The pulverization device 2 is provided with a cylinder 21 for forming a swirling cooling liquid layer, an injection crucible 22 for injecting and supplying molten metal into the cooling liquid layer, and for supplying the cooling liquid to the cylinder 21. The pump 26 and other means.

As shown in FIG. 2, the tubular body 21 has a cylindrical shape, and a lid body 24 having an opening 23 of an appropriate size in the center portion at the upper end thereof.
Is formed on the outer peripheral side of the upper end portion thereof, and a cooling liquid ejection hole 25 for ejecting and supplying the cooling liquid from the tangential direction along the outer peripheral surface of the cylinder is provided, and a pipe is provided at the discharge port of the pump 26. It is connected. A ring thickness adjusting ring 27 for the cooling liquid layer is detachably attached and replaceable by a bolt 28 on the inner peripheral surface of the middle portion of the cylindrical body 21. A cylindrical net body 29 for draining liquid is continuously provided at the lower end of the tubular body 21, and a funnel body 30 is attached to the lower end thereof.

The cooling liquid ejected from the cooling liquid ejection hole 25 along the inner peripheral surface of the cylindrical body 21 flows down while swirling along the inner peripheral surface of the cylindrical body 21, and at the same time, the cooling liquid having a constant inner diameter by the action of the centrifugal force of the swirling flow. Form layer 31. The cooling liquid which has flowed over the layer thickness adjusting ring 27 and flows down is discharged from the net body 29 and flows into the funnel body 30 by the action of centrifugal force. The cooling liquid discharged from the net 29 is
It is collected in the tank 33 from the bottom of the cover 32 provided on the outer periphery of 29. The coolant in the tank 33 is cylindrical by the pump 26.
Circulated to 21. The tank 33 may be provided with a replenishing cooling liquid supply pipe (not shown), and a cooler may be appropriately interposed in the tank or in the circulation path. Water is generally used as the cooling liquid.

An injection crucible 22 as a molten metal supply means is provided above the lid 24, and a heating coil 36 is provided on the outer periphery thereof.
Is wound and formed with a nozzle hole 37 at the bottom thereof. The molten metal is pressure-fed from the continuous pouring device 1 to the injection crucible 22.

The continuous liquid eliminator 3 includes a rotating drum 41 which is expanded upward, and an intermediate peripheral wall of the drum 41 is formed of a screen plate having a large number of pores. A large number of convex ribs 42 for sending out to the are formed. A cooling liquid recovery cover 43 is provided on the outer peripheral surface side of the rotary drum 41, and the drained cooling liquid is recovered in the tank 33 from the bottom thereof. Further, a metal powder recovery cover 44 is provided above the rotary drum 41, and a discharge chute 45 is attached.

The continuous drying device 4 includes a drying container 47 having a flow 48 having a large number of pores, and a supply device 49 having a rotary feeder for supplying a wet raw material from the upper part of the container 47.
And a hot air generator 50 for supplying hot air from the lower part of the container 47, and a cyclone 51 for collecting fine powder from the exhaust air discharged from the upper part of the container 47, and the upper and lower side walls of the container 47. A discharge pipe 52 is attached to the.

In order to carry out the present invention, first, the pump 26 is operated to form a cooling liquid layer 31 that flows down while swirling at high speed on the inner peripheral surface of the cylindrical body 21.

Next, the molten metal in the crucible 22 is pressure-fed from the continuous pouring device 1 to the injection crucible 22 provided in the upper part of the cylinder 21.
38 is sprayed from the nozzle hole 37 to the inner surface of the cooling liquid layer 31, divided, rapidly cooled and solidified to be powdered.

The metal powder is discharged from the lower end opening of the liquid 21 together with the cooling liquid forming the cooling liquid layer 31. Most of the coolant is a funnel body 30
By the action of the centrifugal force of the cooling liquid itself, it is separated and discharged by the mesh 29 before it flows down to the. The metal powder and the cooling liquid flowing down to the funnel body 30 are continuously supplied to the continuous liquid remover 3,
It is drained by the action of centrifugal force. At this time, since the treated material is primarily deliquored by the net 29, the deliquoring efficiency is good.

The wet metal powder discharged from the discharge chute 45 of the continuous dewatering device 3 is subsequently put into the supply device 49 of the continuous drying device 4 and sent into the drying container 47 by the rotary feeder. The fluidized bed 53 is formed by hot air blown from below on the fluidized bed 48 in the container 47, the wet metal powder is vigorously mixed with hot air in the fluidized bed 53, heat exchanged, and quickly dried, Usually, it is taken out to the outside through the discharge pipe 52 by overflow.

In carrying out the present invention, the continuous pouring device, the continuous dewatering device, and the continuous drying device are not limited to those described above, and any appropriate device supplied to the market can be used.

(Effects of the Invention) As described above, the method for continuously producing rapidly solidified metal powder according to the present invention is such that the cooling liquid is jetted and supplied along the inner peripheral surface of the cylindrical body while swirling along the peripheral surface of the cylindrical body. Since the flowing cooling liquid layer is formed, the inner peripheral surface of the cooling liquid layer into which the molten metal is poured is stabilized, and the temperature of the cooling liquid layer is easily and uniformly maintained. Further, since the molten metal is injected and supplied into the cooling liquid layer, the rapidly solidified powder having a constant quality is continuously produced, the productivity is high, and the injection nozzle is not clogged. Further, since the metal powder flowed down together with the cooling liquid is continuously removed and dried, the time for contact with the cooling liquid can be shortened, the gas content can be reduced, and the gas generated during processing such as extrusion can be reduced. It can contribute to the prevention of defects.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a metal powder production facility for carrying out the present invention, FIG. 2 is a cross-sectional view of a cylinder for continuously producing metal powder, and FIG. 3 is a view of a conventional metal powder production apparatus. FIG. 21 …… Cylinder, 31 …… Coolant layer.

Claims (1)

[Claims] 1. A cooling liquid layer (31) is formed by jetting and supplying a cooling liquid along the inner peripheral surface of a cylindrical body (21) while swirling along the peripheral surface of the cylindrical body, and forming the cooling liquid layer. The metal melt is injected from the inner peripheral surface side of (31), divided by the cooling liquid layer (31) and cooled and solidified to obtain a metal powder, and the metal powder flowing down together with the cooling liquid from the cylindrical body (21) is continuously supplied. A method for continuously producing rapidly solidified metal powder, which comprises continuously drying after deliquoring.