JP3068003B2 - Powder rolling electric sintering method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for electrically sintering a powder roll provided with a rolling roll and a current rolling roll.

[0002]

2. Description of the Related Art In a conventional electric powder rolling method, electric heating for forming and sintering powder is performed by a pair of rolling rolls.

[0003] Here, since an electric current for heating the powder is carried out by a pair of opposed rolling rolls, a current flows through the powder only for a short time between the rolls.

[0004]

For this reason, the heating efficiency of the powder is low, the current per sheet width to be molded for sintering is large, and a large-capacity power source is required.

[0005] Further, since a metal roll capable of withstanding a high rolling load is used as a rolling roll also serving as a forming roll, there is a problem that a metal forming material adheres to the roll during electric heating. .

The present invention has been made in view of the above circumstances, and has as its object to provide a powder energization rolling method for efficiently heating and sintering powder with a small current so that a formed material does not adhere to a rolling roll. .

[0007]

SUMMARY OF THE INVENTION According to the present invention, a powder formed into a plate shape with at least one pair of metal rolling rolls is passed through at least two pairs of graphite rolling rolls, heated by heating, and rolled and sintered. At this time, a DC current for heating is applied between a plurality of pairs of energized rolling rolls made of graphite, and a pulsed energization is performed between the opposed energized rolling rolls made of graphite to promote sintering. This is a powder rolling electric sintering method of rolling and sintering.

[0008]

When the powder formed by one or more pairs of metal rolling rolls is passed through two or more pairs of graphite rolling rolls connected to a pulse and a DC power source, a pulse is applied between the opposing rolls and between the pair of rolls. Sintering proceeds while being energized and DC energized and heated. In this case, since the current flows between the pair of rolls, the time for energizing and heating is long, and heating is performed efficiently with a small current. In addition, since the material of the energizing rolling roll is graphite different from the metal powder to be formed, the heated forming material does not easily adhere to the rolling roll.

[0009]

FIG. 1 shows an embodiment of the present invention. 1 is a vibrator, 2
Is a diaphragm for applying vibration to the powder, and is connected to the vibrator 1. 3 is a hopper for storing powder and supplying it to a rolling roll. 4 is a powder, 5 and 6 are metal rolling rolls for rolling and forming the powder, 7, 8, 11, and 12 are current-carrying rolling rolls made of graphite, 9 is a pulse power supply, 10 is a DC power supply, 13
Is a forming material, and 14, 15 and 16 are driving devices such as motors for driving the respective rolling rolls.

Next, the operation will be described.

The powder is put into a hopper 3 and is uniformly fed to rolling rolls 5 and 6 by being subjected to vibration from a diaphragm 2 to be roll-formed.

When the formed body passes through the rolling rolls 7, 8, 11, and 12, it receives a pulse current for promoting sintering from a pulse power source 9, and receives a DC current for heating from a DC power source 10. And the rolling rolls 11 and 1
Sintering proceeds while receiving the pressure in Step 2.

At this time, since the molding material which receives the DC current is a portion between the roll pairs 7 and 8 and the roll pairs 11 and 12,
The current-carrying part is long, and high heating efficiency can be realized.

Further, the electric rolling rolls 7, 8, 11, 12
Is made of graphite, so that the compact is hardly adhered to the rolls despite being in contact with the heated metal powder compact at high pressure.

FIG. 2 shows Cu-8 obtained by the method of the present invention.
It is a metallographic photograph of the sintered compact of a% Sn alloy. The current value per formed sheet width is 20 A / mm, which is about one tenth of the value obtained by the conventional method. Although the cavities remain, it can be seen that sintering is progressing.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that changes can be made without departing from the spirit of the present invention.

[0017]

According to the present invention, the following excellent effects can be obtained.

As described above, according to the present invention, by using a rolling roll for forming powder and a plurality of pairs of energizing rolls made of graphite, pulse energization for promoting sintering of powder raw materials is performed. The compact can be efficiently heated and sintered with a small current, and a sintered body can be continuously manufactured without a molding material adhering to a roll.

Therefore, it is possible to efficiently and continuously produce a plate made of a material which is difficult to produce by the melting method or whose raw material is available only as a powder.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention.

FIG. 2 shows Cu sintered using an apparatus according to an embodiment of the present invention.
It is a microscope structure photograph of a -8% Sn alloy.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vibrator 2 Vibrating plate 3 Hopper 4 Powder 5, 6 Metal rolling roll 7, 8, 11, 12 Graphite energizing rolling roll 9 Pulse energizing power supply 10 DC energizing power supply 13 Molding material 14, 15, 16 Roll drive device

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hideaki Takaya 4-6-22 Kanon Shinmachi, Tori-ku, Hiroshima-shi, Hiroshima Research Laboratory, Mitsubishi Heavy Industries, Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB Name) B22F 3/14 101 B22F 3/18

Claims (1)

(57) [Claims] 1. A method in which a plurality of graphite-made powders are passed through two or more graphite current-carrying rolls, heated, and roll-sintered. Apply a DC current for heating between the pair of energized rolling rolls,
A current-driven powder rolling sintering method, characterized in that a pulsed current for promoting sintering is applied between opposing current-carrying rolls made of graphite to roll-sinter a plate-shaped compact.