JPS5895667A - Silicon carbide ceramic body bonding method and device - 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 The present invention relates to a method of joining an I81IFi silicon carbide ceramic body and its ji[.

Silicon carbide is a material that is currently being developed as a material for combustion tubes, scrolls, and turbine exhaust materials for automobile turbine engines, and has the advantage of not decreasing its strong rotation even at temperatures as high as 41,500°C. are doing. In order to use such materials as willow construction materials or general high-temperature industrial materials, it is easier to manufacture small ones than large ones from the viewpoint of workability, so small pieces are joined to make large ones. method is preferred.

In order to join such silicon carbide ceramic bodies, the conventional technique involves sandwiching a homogeneous mixed powder of silicon carbide and carbon between the ceramic bodies, and then transferring the carbon in the mixed powder to silicon carbide. A sufficient amount of metallic silicon powder is placed around the bonding layer and heated and melted to allow the melted silicon to infiltrate into the layer, converting the carbon into silicon carbide, and sintering the silicon carbide to form the bond. I had completed it.

However, this method requires that the materials to be joined and a jig for placing the materials to be joined in the narrow joint area be placed in the furnace, which increases the volume of the heated material in the furnace and makes it difficult to operate. It's thermoeconomically disadvantageous, so it's 5 circles.

The present invention solves the above problems and allows complex structures to be joined by allowing molten silicon to flow down only to the joint, and provides a joining method that can simplify the support jig and a freely movable molten silicon container. The purpose of this book is to provide a bonding device that can supply % molten silicon to a bonding layer having a specific shape.

The method for bonding silicon carbide ceramics of the present invention is to prepare a homogeneous mixture powder of silicon carbide and carbon at a density such that the free silicon content in the silicon carbide bonding layer produced after bonding is 5 to 15 volumes. The mixed powder is sandwiched between the silicon carbide ceramic bodies to be joined to have a uniform thickness, and the molten silicon in a container separated from the silicon carbide ceramic bodies is poured into the uniformly mixed powder section. The device is characterized in that the bonding is completed by K infiltrating into the layer to form silicon carbide.◇ The device of the present invention is also equipped with a heating element and piping for pressure or vacuum, and can be moved from side to side. Mutual treatment and the lower α of wrinkled mutual treatment
The material to be welded is horizontally supported under a nozzle having a diameter of 0.5 to α2. The material to be welded is supported horizontally and is movable and rotated in the horizontal direction. It is characterized by having a body and a vacuum exhaust pipe.

The bonding material layer produced by the method of the present invention is made of a sintered body of silicon carbide. It is preferable to provide pores such that free silicon can exist. When flowing down the molten silicon, it is preferable to carry out under reduced pressure of 1 mHf or less in order to facilitate the penetration of the molten silicon. The melting point of metallic silicon is 1410°C, and at the melting point it immediately reacts with carbon and generates heat, and at the most active part of the reaction, about 1
It reaches 600℃.

The thickness of the bonding material layer mixed with the mixed powder is α05 to C.
LS proverbs are preferred.

If the thickness exceeds αSWt, the bonding strength decreases, and it is operationally difficult to reduce the thickness to 105 or less.

As the silicon carbide ceramic material to be joined, a silicon carbide sintered body obtained by impregnating molten silicon into a uniform mixture of silicon carbide powder and carbon powder, or a mixture of silicon carbide powder and a thermoplastic resin as an organic binder is injected. A silicon carbide sintered body obtained by degreasing and sintering a molded powder compact can be mentioned. An example of the apparatus of the present invention will be described with reference to the drawings. Ingredients 1
．． Crucible above 1 and workpiece 2! 15 is provided in the electric furnace 6 so that the material to be welded in the electric furnace 6 does not come into contact with the molten silicon 7 in the contact 5. While being depressurized, the molten silicon 7 is pressurized by argon gas introduced from the argon suppression pipe 10.06b is an electric furnace cover that isolates the exchange 5 and the electric furnace 6. .

The support 5 is, for example, an isotropic high-density graphite crucible medium, and the lower part thereof is made of a homogeneous or silicon carbide sintered body and is equipped with a molten silicon flow down nozzle 4, and around its outer periphery is a heating means such as a high-frequency induction heating coil 51. 0 nozzle 4 is provided with a diameter of LO5 or L2m (according to the thickness of the bonding material 43 α05 to 15 mm), which is equal to y but slightly smaller (having a diameter of LO5 to L2m). Although the movement range is limited, it can be moved left and right by the operation of the movement device 8 and the movement synchronous motor 9.

The component support 1 is made of a corrosion-resistant and heat-resistant member made of isotropic high-density graphite material, and is provided in the form of being supported by a metal material on both the left and right walls of the electric furnace 6. A synchronous motor for rotating the components other than 6::t2 allows the workpiece 20 to be rotated in the circumferential direction and moved left and right in one axis direction. In the figure, 61 indicates a heating means for the material 2 to be joined, such as a graphite heating element. ◇ All parts other than the heating part in the electric furnace 6 are insulated, the main parts are equipped with cooling equipment, and there is an O-ring with the outside air. Vacuum sealed with rubber or backing.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example silicon carbide powder (manufactured by Fujimi Abrasive Industries, GC#2000,
$4000 and @s o o o mixed in a ratio of 7:2:1) and carbon black (Mitsubishi Kasei Corporation)
Powder r: 195f, which is a uniform mixture of Diablack manufactured by Diablack ■) at a weight ratio of t8 to 1, is dispersed in a mixture of full 7 reel alcohol and furan resin 111 and used as a bonding material. Pipe (outer diameter 88 pigeon inner diameter 52
After applying the above-mentioned bonding material to the joint with a length W1 of 150 m), the structure was supported by the structure support 1.1, and the joint was fitted as shown in FIG. Furthermore, pressure is applied from both ends of the materials to be joined 2, 2, so that the thickness of the joining material layer is α15 and the bulk specific gravity is approximately t5.
I set it to 7f/cd. Next, the inside of the electric furnace 6 was evacuated to 1 H1 or less using the vacuum exhaust pipe 9, and the materials 2 to be joined were heated to 1450°C using the graphite heating element 6a. After evacuating through the vacuum exhaust pipe 10, the high frequency induction heating coil 5a is
Contains 1 ton of heated and melted silicon, inner diameter α15
When the water is allowed to flow down from the nozzle 4 to the bonding material layer 3,
A pressure of 5 to 3004/- is applied from both ends of the material to be joined 2.2. The structure support 1 can rotate the workpiece 2 in synchronization with the movement of the crucible 1@s. Bonding material layer 3 in advance
The material to be joined 2 is held at a predetermined position in the electric furnace 6 by defining the shape, and the molten silicon 7 is flowed down along the joining material layer 3 under computer control using programming. The molten silicon 7 is made to flow down from the nozzle 4 by pressurizing it with its own weight or with argon gas introduced from the argon suppression pipe 10 which also serves as an exhaust pipe. The amount of flow is controlled according to the diameter of the nozzle, so that a bonding material layer with a uniform thickness of 115 mm in this case can be obtained.

Example 2 During reaction sintering, the atmosphere in the furnace was maintained at below K 1 wHf, and the entire amount of molten silicon was flowed down to complete the bonding.A propane gas/oxygen flame was blown into the bonding tube prototyped in Example 1. Heating for 10 minutes (the temperature of the inner wall of the tube is approximately 600℃)
), then it was cooled by blowing compressed air from outside. This operation was repeated 1000 times as one cycle, but no defects occurred.

In conventional bonding methods, the bonded material and the jig for placing the bonded material were not separated, so the bonded object was stuck to the jig due to unreacted silicon, and the jig was required to attack the bonded object. However, with the method and apparatus of the present invention, molten silicon can be mechanically flowed down to the joints even if the joints have an irregular shape, and a strong joint can be created. Now you can get

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a welding situation according to the present invention, and FIG. 2 is a schematic cross-sectional view of a manufacturing apparatus according to the present invention.・・Binding material layer 4・−・Nozzle 5・・Crucible>l
s a = high frequency induction heating coil 6... electric furnace
61-...Graphite resistance heating element 6b...Electric furnace bag
7... Molten silicon 8... Silica transfer device! ... Synchronous motor for movement 10 ... Argon suppression tube (vacuum exhaust pipe) 11 ... Silicon inlet 12 ... Synchronous motor for rotating the component 15 ... Vacuum exhaust pipe spear 1 Figure 3

Claims (1)

[Scope of Claims] (A homogeneous mixed powder of silicon 13m and longitudinal cables is made into a powder such that the content of free silicon in the silicon carbide bonding layer formed after welding is St isis volume - The silicon carbide ceramic bodies to be bonded are interposed with a uniform thickness, and the OSm silicon is placed in a container separated from the silicon carbide ceramic bodies with the above-mentioned uniform thickness.
Silicon carbide-4, which is characterized in that it is bonded by flowing down to the end of a warm temperature to form silicon carbide! How to join Tsuntsuku body. (2) A silicon carbide ceramic body is heated in a vacuum to 1420 to 1.00°C and placed in a round shape, and the molten silicon flows down due to the weight of the S-fused silicon or the pressure of an inert gas.Claim 1i1) The method described in J. -) A crucible that is equipped with a heating element and piping for pressurization or evacuation and can be moved from side to side, and a turtle Os to 1 at the bottom of the crucible.
A supporting tool that horizontally supports the material to be welded under a nozzle having a diameter of 2-0 g and is capable of horizontal movement and rotation,
A welding apparatus for a vertical silicon ceramic structure, further comprising a heating element for heating materials to be welded under vacuum and a vacuum exhaust pipe.