JPH09268302A - Production of continuous sintered body utilizing direct conducting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for continuously producing a sintered sheet by direct conductive heating rolling capable of producing a direct sintered sheet material from powder, capable of pulse conducting to a green compact for promoting sintering and in which the green compact is efficiently heated by a small electric current and is sintered to prevent the sticking of the sintering material to rolling rolls. SOLUTION: Powder is fed to a hopper 3 and is formed into rolled compacted body by rolling rolls 5 and 6. This compacted body is applied with pulse conducting for promoting sintering when it passes through the space between rolling rolls 7 and 8. After that, the compacted body is applied with d.c. conducting between a pair of rolls 7-8 and 11-12, is heated to a sintering temp. and is sintered under pressure by the rolling rolls 11 and 12. In this heating, heating efficiency is high since the conducting part is long. The conductive rolling rolls 7-8 and 11-12 the parts for heating the compacted body are made of graphite, therefore, the sticking of the compacted body to the rolls hardly occurs.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In the conventional energizing powder rolling method, energizing heating for powder molding and sintering is performed by a pair of rolling rolls (Japanese Patent Laid-Open No. 22868/1994).

Here, since the energizing current for heating the powder is performed by the pair of opposed rolling rolls, the 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 plate width to be formed for sintering is large, and a large-capacity power source is required.

Further, since the rolling roll also serving as the forming roll is a metal roll that can withstand a high rolling load, there is a problem that the metal forming material adheres to the roll during electric heating. .

In view of the above situation, it is an object of the present invention to provide a powder electrification rolling method in which powder is efficiently heated with a small current to sinter the powder so that the forming material does not adhere to the rolling roll. .

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a plate-shaped molded body in which powder formed by one or more pairs of metal rolling rolls is heated by two or more pairs of graphite current-carrying rolls by pulse and direct current or alternating current. The present invention relates to an electric rolling sintering method characterized by 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 the pulse and DC power source, the powder is pulsed between the opposing rolls and between the roll pairs. Electric current and direct current are applied, and sintering proceeds while being heated. In this case, since the current flows between the pair of rolls, the time during which the current is applied and heated is long, and the current is efficiently heated with a small current. Further, since the material of the electric rolling roll is graphite different from the metal powder to be formed, the heated forming material is unlikely to adhere to the rolling roll.

[0009]

FIG. 1 shows an embodiment of the invention. 1 is a shaker, 2
Is a vibrating plate for vibrating the powder and is connected to 1. 3 is a hopper for storing powder and supplying it to the rolling rolls. 4 is powder, 5 and 6 are metal rolling rolls for rolling and forming powder, 7, 8 and 11 and 12 are electric current rolling rolls made of graphite, 9 is pulse power supply, 10 is direct current power supply, 13 is molding material, Reference numerals 14, 15, and 16 are drive 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 sent to rolling rolls 5 and 6 by being vibrated by a vibrating plate 2 to be roll-formed.

The moldings here are 7, 8, and 1
When passing through the rolling rolls 1 and 12, the pulse current for promoting the sintering is applied from 9 and the direct current for heating is applied from 10 and the firing is performed while being pressed by the rolling rolls 11 and 12. The knitting progresses.

At this time, the molding material to which direct current is applied is 7,
Since it is the portion between the roll pair of 8 and the roll pair of 11 and 12, the energized portion is long and high heating efficiency can be realized.

Further, since the current-rolling rolls 7, 8, 11 and 12 are made of graphite, even if they are in contact with the heated metal powder compact at high pressure, the compact adheres to the roll. Is unlikely to happen.

FIG. 2 shows Cu-obtained by the method of the present invention.
It is a metallographic photograph of the sintered compact of 8% Sn alloy. The current value per formed plate width is 20 A / mm, which is about 1/10 of the current value obtained by the conventional method. It can be seen that the sintering is progressing although the cavity remains.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that changes can be made without departing from the gist of the present invention.

[00017]

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

As described above, according to the present invention, a plurality of rolling rolls for molding powder and a plurality of graphite current-carrying rolls are used to perform pulsed current for promoting the sintering of the powder raw material. Therefore, the green compact can be efficiently heated and sintered with a small electric current, and the sintered body can be continuously manufactured without the molding material sticking to the roll.

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

[Brief description of drawings]

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

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

[Explanation of symbols]

 1 Vibrators 2 Vibration Plates 3 Hoppers 4 Powders 5 and 6 Metal Rolling Rolls 7, 8, 11 and 12 Graphite Current Rolling Rolls 9 Pulse Current Power Supply 10 Direct Current Power Supply 13 Forming Materials 14, 15 and 16 Roll Drive Devices

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideaki Takatani 4-6-22 Kannon Shinmachi, Rooster-ku, Hiroshima City Mitsubishi Heavy Industries, Ltd. Technology Research Division Hiroshima Research Institute

Claims (1)

[Claims] 1. A plate-shaped compact is rolled and sintered by subjecting powder formed by one or more pairs of metal rolling rolls to electrical heating by pulse and direct current with two or more pairs of graphite electrical rolling rolls. Current rolling and sintering method.