JPS6289801A - Mixer for whisker and metallic powder - Google Patents

Abstract

PURPOSE:To uniformly and efficiently disperse whiskers and mix the whiskers and metallic powder by constituting a titled mixer in such a manner that ultrasonic waves can be irradiated over the entire part of a liquid mixture composed of the whiskers and org. solvent and the liquid mixture composed of said liquid mixture added with the metallic powder to be stirred in a stirring tank. CONSTITUTION:A valve 6, a valve 7 and a valve 9 are closed and the org. solvent and whiskers are thrown into the stirring tank 1. The ultrasonic waves are irradiated from an ultrasonic oscillator 3 to the liquid mixture. The intertwisted whiskers are unraveled by the cavitation effect generated by such irradiation, by which the whiskers are dispersed into the solvent. The solvent is further convected by a stirrer 2 and the ultrasonic oscillation is uniformly applied to the whiskers in the solvent, by which the dispersion effect of the whiskers is additionally improved and the addition and uniform mixing of the metallic powder to and with the whiskers are made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an apparatus for uniformly mixing whiskers and metal powder in a solvent for producing whisker-reinforced metal composite materials.

<Prior art> Aβ and Al1 alloy, Ti and Ti alloy, Mg
Whisker-reinforced metal composite materials, which are made by combining lightweight metals such as Mg alloys and whiskers such as SAC, si3 N4, which are lightweight, high strength, high elastic modulus, and have excellent heat resistance, have high specific strength, high specific rigidity, and wear resistance. It also has excellent heat resistance compared to fiber-reinforced plastics. For this reason, it is attracting attention mainly in the field of transportation equipment such as aerospace aircraft and automobiles, which require light weight and heat resistance, and also as a material for sporting goods.

A widely used method for manufacturing the whisker-reinforced composite material is to mix whiskers and metal powder and mold the mixture by hot pressing, etc. However, whiskers have a diameter of 0.
．． 1 to 1.0 micrometers, and 50 to 200 micrometers in length, usually several tens to hundreds of them are intertwined to form a fluff-like shape, and the difference in bulk density between whiskers and metal powder is large. Listen (SiC whisker: 0.1 g/aJ,
Si3 N4 whisker: o, tg/cj, -350
Metush All powder: 0.9 g/aJ).

There is also a large difference in density (SiC whiskers: 3.2g/
cr1. Si3 N4 whisker: 3.2g/a
J, Ai: 2.7 g/cj, Ti 4.
6 g/aA, Mg 1.7 g/cj), therefore V
Mixing is difficult with a mixer, and with a ball mill, the whiskers break and the reinforcing effect is reduced.

However, in order to solve the same problem, the whiskers were disentangled by applying ultrasonic vibrations in an organic solvent, then metal powder was mixed into this, the organic solvent was removed using a suction filtration method, and then the whiskers were vacuum dried. A method for uniformly mixing whiskers and metal powder, which is characterized by completely removing the organic solvent, was proposed by the applicant (Japanese Patent Application No. 59-109038), and the mixing device disclosed in the proposal is as follows. It is.

That is, FIG. 3 is a schematic diagram of the mixing device for whiskers and metal powder disclosed above, in which 11 is a stirring tank;
A stirrer 12 is provided within the same type 11 . Further, a circulation pipe 14 is connected to the stirring tank 11, and a pump 15 and an ultrasonic vibrator 13 are interposed in the middle of the vibrator 14, respectively.
has been inserted. Further, a discharge vibrator 17 is connected to a midway portion of the pipe 14 via a valve 16.

To mix whiskers and metal powder using the above device, an organic solvent is stored in the stirring tank 11 with the valve 16 closed, and then the whiskers are placed in the solvent. This mixture of whiskers and organic solvent is circulated between the circulation pipe 14 and the stirring tank 11 by the pump 15. During the circulation, ultrasonic waves are received from the ultrasonic vibrator 13,
This untangles the whiskers.

Next, metal powder is added in the stirring tank 11, and the whiskers and the mixture of metal powder and solvent are passed through the circulation pipe 14 and the stirring tank 1.
1 and rotate the stirrer 12 to stir and mix. In this case, stirring while applying ultrasonic waves will further improve the uniform mixing effect.

<Problems to be Solved by the Invention> As described above, the mixing device disclosed in the earlier application can also achieve an excellent dispersion state of the whiskers and a uniform mixing state with the metal powder. Ultrasonic irradiation of the mixed liquid, in other words, repeated irradiation of a part of the mixed liquid for a short time, is not necessarily sufficient from the viewpoint of desiring better whisker dispersion, and also from the viewpoint of work efficiency. There was a problem.

Means for Solving the Problems> In view of the above problems, the present invention provides a method for efficiently irradiating the entire mixed liquid in a stirring tank with ultrasonic waves.
The purpose of this device is to disperse the whiskers and mix the whiskers with the metal powder sufficiently uniformly and efficiently.As a means to achieve this purpose, a stirring device consisting of a stirring tank and a stirrer is used. , an ultrasonic vibrator is installed so that ultrasonic waves can be irradiated from inside the tank or from outside the tank to a mixed solution of whiskers and an organic solvent that is stirred in a stirring tank, and to a mixed solution in which metal powder is further added to the mixed solution. However, a configuration was adopted in which a cooling means was installed on the side wall of the stirring tank so that the mixed liquid could be cooled.

<Function> Next, the whisker dispersion effect by ultrasonic waves will be explained. When an organic solvent containing whiskers is irradiated with ultrasonic waves and subjected to ultrasonic vibrations, the air contained in the solvent forms microbubbles and the bubbles vibrate violently and burst, a phenomenon known as cavitation. . The pressure generated when these bubbles burst is said to be 200 to 300 atmospheres.

In other words, this kind of cavitation occurs even within the tangled hairball of the whiskers, and the tangles are disentangled by the high pressure generated at this time.

Note that the organic solvent irradiated with ultrasonic waves generates heat and rises in temperature due to ultrasonic vibrations. The temperature increase causes the microbubbles caused by the cavitation effect to grow and float, thereby reducing the cavitation effect. The heat generated by the temperature increase is absorbed by a cooling jacket provided on the side wall of the stirring tank and passing through cooling water.

<Example> Examples of the present invention are shown below. However, it should be noted that the present invention is not limited to this.

(A) FIG. 1 is a schematic vertical cross-sectional view of an embodiment in which ultrasonic vibrators 3 are distributed on the outside of a stirring tank 1. 2 is a stirrer, and 4 is a water cooling jacket provided in contact with the outer wall of the stirring tank 1. A cooling water inlet 4a is provided at the lower part of the jacket 4, and a cooling water outlet 4b is provided at the upper part.

A mixed liquid discharge pipe 5 is connected to the bottom of the stirring tank 1, mixed liquid discharge control valves 6 and 7 are interposed in the middle of the discharge pipe 5, and a compressed air injection pipe is connected in the middle between the valves 6 and 7. 8 is connected, and 9 is a compressed air control valve provided on the injection pipe 8.

Next, a method of mixing whiskers and metal powder according to this embodiment will be explained.

First, an organic solvent (for example, ethyl alcohol) and whiskers are put into the stirring tank 1 with the Halpro, valve 7, and valve 9 closed, and the mixed liquid is irradiated with ultrasonic waves from the ultrasonic vibrator 3. The resulting cavitation action causes the whiskers to become disentangled and dispersed in the solvent. Furthermore, the stirrer 2 causes the solvent to convect and evenly applies ultrasonic vibrations to the whiskers in the solvent, thereby further enhancing the dispersion effect of the whiskers, and adding metal powder to achieve uniform mixing.

During the above operation, cooling is continued by passing cooling water through the water cooling jacket.

Further, during the above operation, the mixed liquid discharge control HALPRO and the compressed air control valve 9 are opened to intermittently send compressed air into the stirring tank 1. This makes it possible to prevent whiskers and metal powder from depositing on the bottom of the stirring tank 1, the top of the valve 6, and the like.

CB) FIG. 2 is a schematic vertical cross-sectional view of an embodiment in which the ultrasonic vibrator 3 is movable up and down within the stirring tank 1 from above the stirring tank 1.

The ultrasonic vibrator 3 is positioned on the center line of the stirring tank 1 and is supported by a hanging device 10 so as to be movable up and down within the stirring tank 1, depending on the level of the mixed liquid stored in the stirring tank 1. The position is adjusted to ensure sufficient ultrasound irradiation.

In addition, 2 is an agitator, 4 is a water cooling jacket, 4a is a cooling water inlet, 4b is a cooling water outlet, 5 is a mixed liquid discharge pipe, 6 and 7 are mixed liquid discharge control valves, 8 is a compressed air injection pipe, and 9 is a Compressed air control valves are provided in the same manner as in Example (A).

<Effects of the Invention> As described above, the present invention enables ultrasonic irradiation to be applied to the entire mixture of the whisker and organic solvent stirred in the stirring tank and the mixture to which metal powder is added. Therefore, the time for irradiating the whiskers with ultrasonic waves is longer than in the case of irradiating the conventional circulating mixed liquid with the ultrasonic waves. In other words, when considering one whisker hairball, in the conventional circulation method, the irradiation is repeated for a short time only while passing through the ultrasonic irradiation area, whereas the mixing device of the present invention In this case, the whisker hairballs are irradiated with ultrasonic waves for the entire irradiation time, and the hairballs are efficiently and effectively dispersed. Therefore, mixing with metal powder can be efficiently and effectively achieved in an excellent uniform state, improving productivity and making it possible to obtain a better whisker-reinforced metal composite material, which has an industrial value. is significant.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical cross-sectional view of an embodiment of the present invention in which ultrasonic vibrators are distributed on the outside of a stirring tank. FIG. 2 is a schematic vertical cross-sectional view of an embodiment of the present invention in which an ultrasonic vibrator is movable up and down inside the stirring tank from above the stirring tank. FIG. 3 is a schematic diagram of a conventional mixing device for whiskers and metal powder (disclosed in Japanese Patent Application No. 59-109038). ■... Stirring tank, 2... Stirrer, 3... Ultrasonic vibrator, 4... Water cooling jacket, 4a... Cooling water inlet, 4b... Cooling water outlet, 5...・Mixed liquid discharge pipe, 6
... Mixed liquid discharge control valve, 7... Mixed liquid discharge control valve, 8... Compressed air injection pipe, 9... Compressed air control valve, 10... Hanging device, 11... Stirring tank , 12... Stirrer, 13... Ultrasonic vibrator, 14... Circulation pipe, 15... Pump,
16... Valve, 17... Discharge pipe.

Claims (1)

[Scope of Claims] 1. In a stirring device consisting of a combination of a stirring tank and a stirrer, a mixture of whiskers and an organic solvent stirred in the stirring tank and a mixture of metal powder further added to the mixed liquid are provided. ,
Whiskers and metal powder, characterized in that an ultrasonic vibrator is installed so that ultrasonic waves can be irradiated from inside the tank or from the outside of the tank, and a cooling means is installed on the side wall of the stirring tank so that the mixed liquid can be cooled. mixing equipment. 2. The device for mixing whiskers and metal powder according to claim 1, which comprises an ultrasonic vibrator installed outside the stirring tank. 3. The mixing device for whiskers and metal powder according to claim 1, which comprises an ultrasonic vibrator that is movable up and down within the stirring tank from above the stirring tank. 4. An apparatus for mixing whiskers and metal powder according to any one of claims 1 to 3, further comprising an injection means for injecting compressed air into the stirring tank from a mixed liquid discharge pipe at the bottom of the stirring tank.