JPH06226634A - Water jet machining method - Google Patents

Abstract

PURPOSE:To enable the machining of a silicon carbide sintered body or the like to be conducted with high hardness by using silicon carbide grain as abrasive grain at the time of machining an article by a water jet machining method using liquid intermixed with abrasive grain. CONSTITUTION:In a water jet machining method, the jet-stop of liquid such as water jetted from a jet water nozzle 1 is controlled by a valve 2 disposed upstream of the nozzle 1. Abrasive grain is supplied to a mixing area 4 through an opening part 3. After being mixed with the liquid jetted from the nozzle 1 in this mixing area 4, the mixed abrasive grain is jetted toward an article from the discharge opening 6 of a mixing nozzle 5 to cut the article for machining. In the case of using a silicon carbide sintered body as the machined article, silicon carbide grain (SiO) is used as the abrasive grain, and this SiO grain can be obtained by grinding and grading an ingot obtained by reacting quartzite and coke in an electric resistance furnace.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses water mixed with abrasive particles, and when the article is processed by the water jet method, the abrasive particles are coated with silicon carbide (Si).
C) Water jet processing method using particles.

[0002]

2. Description of the Related Art Conventionally, a water jet processing method has been known in which high pressure water is jetted from a nozzle to process an article. This water jet processing method is industrially used as a main object, which is relatively flexible in terms of material, such as paper, cloth, rubber, leather, wood, and synthetic resin. On the other hand, when processing a material that is difficult to process by the water jet processing method, for example, a relatively hard material such as concrete, ceramic, stone, metal material, glass, or hard synthetic resin, the processing characteristics of the water jet described above are used. In order to process by the above method, a method in which abrasive particles are mixed in a water jet and jetted from a nozzle is used (for example, JP-A-63-120).
No. 098), and as the abrasive particles used for this purpose, garnet has been mainly used conventionally.

[0003]

However, depending on the water jet mixed with garnet, a hard article, for example, a hard article such as a silicon carbide sintered body containing silicon carbide (SiC) and silicon (Si). When processing, there was a problem that it could not be cut, or even if it could be cut, the cutting speed was extremely slow. Particularly, in the case of a plate material, there is a problem that the cutting ability is extremely reduced when the thickness is 5 mm or more. Therefore, as a result of various studies on the above-mentioned conventional problems, the present inventor has found that the problems described above can be solved by using SiC particles, and has reached the present invention.

[0004]

That is, according to the present invention, in a method for processing an article by a water jet method using a liquid containing abrasive particles, water jet processing using SiC particles as the abrasive particles. A method is provided. In the present invention, it is desirable to apply it to processing a hard article such as a sintered body containing 60% by weight or more of silicon carbide.

[0005]

In the present invention, a water jet in which SiC particles are mixed with a liquid (mainly water) as abrasive particles is used. By mixing the SiC particles, unlike the case of mixing the garnet, it is possible to quickly and easily cut a hard article. Further, when a silicon carbide and a silicon carbide sintered body containing silicon are used as the article to be processed, the fine abrasive powder obtained during the processing can be recovered and reused as the abrasive particles. Next, Si
The outline of the water jet processing method using C particles will be described.

FIG. 1 shows an example of a known nozzle device used in the water jet processing method. A liquid such as water jetted from the jet water nozzle 1 is a jet water nozzle 1.
Injection and stop are controlled by a valve 2 arranged on the upstream side of. The SiC particles are supplied to the mixing region 4 through the opening 3 of the nozzle for SiC particles, and in this mixing region 4, the SiC particles are mixed with the liquid ejected from the nozzle 1 for jet water, and the discharge port 6 of the mixing nozzle 5 is used. It is jetted toward an article (not shown) to cut and process the article.

The SiC particles are usually obtained by crushing and sizing an ingot obtained by reacting a silicon oxide raw material (silica stone) and a carbon material (coke) in an electric resistance furnace. The particle size of the SiC particles used is not particularly limited, but is preferably in the range of 20 mesh (1000 μm) to 400 mesh (30 μm). If it is less than 400 mesh, the polishing property is lowered and the raw material cost is increased, and if it exceeds 20 mesh, the nozzle is easily clogged, which is not preferable. The SiC particles have a large hardness, and a hard material such as a silicon carbide sintered body can be easily processed.

The amount of SiC particles used as abrasive particles is 50 to 200 g / min / min because of the high raw material cost.
It is preferably in the range of minutes. If the amount of SiC particles is less than this, the polishing property is deteriorated, which is not preferable. It is considered that the reason why such processing is possible is to use abrasive particles having a hardness equal to or higher than the hardness of the object to be processed. Therefore, the greater the hardness difference, the higher the processing efficiency. A low-priced high hardness material that is generally commercially available is SiC, and it is extremely convenient to use this.

In order to improve the spalling resistance, a heat-resistant shelf board made of a silicon carbide sintered body or the like is generally provided with a slit (groove) 12 in the shelf board 11, for example, as shown in FIG. However, when a water jet processing method in which SiC particles are mixed is applied to the cutting processing of the slit 12, the shape of the slit tip portion 13 forms a semicircular shape according to the shape of the mixing nozzle 5 (FIG. 1). When the slit tip portion 13 is angular, stress cracks often occur from the tip portion 13, but by forming the semicircle as described above, the occurrence of stress cracks is prevented and the shelf life is extended. be able to.

Further, when the slit is processed using SiC particles, the upper surface portion 14 of the slit 12 is wide and the lower surface portion 15 is wide as shown in the schematic cross-sectional view of the slit portion of the shelf plate of FIG. Since it is formed in a narrow shape, it is necessary to prevent the refractory coating material, grain sand, dust generated during heat treatment, etc. applied to the surface of the shelf from dropping from the slit 12 and filling the slit 12 with a filler. Moreover, it is possible to prevent the filler from dropping due to deterioration of the filler itself.

[0011]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to these examples. (Examples 1 to 8 and Comparative Examples 1 to 9) By the water jet processing method using the jet nozzle device shown in FIG.
The outlet pressure of the jet water nozzle 1 is 3000 Kgf / c
m ² and SiC particles and garnet particles are used as the abrasive particles. The particle diameter of each particle, the mixing amount, the diameter of the abrasive particle nozzle opening 3 and the jet water nozzle 1
The diameter of each is changed as shown in Table 1, and a plate material made of a silicon carbide sintered body (Si-SiC) containing 80% by weight of silicon carbide and 20% by weight of silicon is cut, and its cutting performance (cutting Speed) tested. The results are shown in Table 1.

The SiC particles used in Examples 1 to 7 are manufactured by Showa Denko, the SiC particles used in Example 8 are manufactured by ESK, and differ from other SiC in that the raw material is rounded. As is clear from the results shown in Table 1, S was used as the abrasive particles.
It can be seen that the cutting performance is far better when iC particles are used than when garnet is used.

[0013]

[Table 1]

[0014]

As described above, according to the present invention,
By using SiC particles as the abrasive particles used in the water jet processing method, it is possible to easily process a silicon carbide sintered body having a high hardness. Also, when slitting is performed on the shelf board,
Since the shape of the tip of the slit can be processed into a semicircular shape, it is possible to prevent the occurrence of cracks from the tip of the slit and extend the life of the shelf board. Further, since the slit can be formed in such a shape that the upper surface portion in the cross section is wide and the lower surface portion is narrow, the refractory coating material, grain sand, dust, etc. do not fall from the slit, and it is not necessary to fill the slit with a filler material. Has the excellent effect of.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an example of a jet nozzle device used in a water jet processing method of the present invention.

FIG. 2 is a plan view showing an example of a shelf board.

FIG. 3 is a schematic cross-sectional view showing a slit portion of a shelf board.

[Explanation of symbols]

 1 Jet Water Nozzle 2 Valve 3 Abrasive Particle Nozzle Opening 4 Mixing Region 5 Mixing Nozzle 6 Discharge Port 11 Shelf Board 12 Slit 13 Slit Tip 14 Slit Top 15 Slit Bottom

Claims (2)

[Claims] 1. A method for processing an article by a water jet method using a liquid in which abrasive particles are mixed, characterized in that silicon carbide (SiC) particles are used as the abrasive particles. 2. The water jet processing method according to claim 1, wherein the article is a sintered body containing 60% by weight or more of silicon carbide.