JP3137737B2 - Si-SiC shelf - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Si--SiC material having high strength and excellent oxidation resistance, creep resistance and spalling resistance, which can be preferably used for rapid firing furnaces for porcelain and tiles. about the shelves.

[0002]

2. Description of the Related Art Conventionally, silicon carbide (SiC) -based sintered bodies have been
Due to its excellent heat resistance and fire resistance, it occupies an industrially important position, and is widely used as, for example, ceramics such as insulators, sanitary ware, tableware, picture frames and ceramic pipes, and shelves for firing tiles and the like. Among such SiC-based sintered bodies, SiC and S
Although a Si-SiC sintered body containing i as a component is known, there is no example of applying this to a shelf plate until now.

Further, when firing the above-mentioned ceramics, tiles, etc., a refractory shelf made of SiC and provided with cuts (slits) from the edges (Japanese Utility Model Laid-Open No. 49-46044).
No.), and mullite, alumina, clay,
SiC that fills in fillers such as fibers to prevent foreign matter from falling through gaps in slits (bolo-free phenomenon)
A high quality refractory shelf board (Japanese Utility Model Publication No. 54-33974) is used. In such a refractory shelf, even under severe use conditions in which the temperature rise rate per hour exceeds 400 ° C., the stress is relieved by the slits, and the shelf has a thermal effect. The excellent effect that spalling and mechanical spalling hardly occur is recognized.

[0004]

Since a Si-SiC sintered body has high strength and excellent oxidation resistance and creep resistance, if it can be applied to a shelf, it can be placed on a sintering object such as ceramics. Can be increased and the durability is further improved, which is extremely preferable from the viewpoint of improving the firing efficiency and cost. On the other hand, when applying a Si—SiC sintered body to a shelf board, it is necessary to provide a slit from an end for stress relaxation and fill a filler in the slit to prevent a bolstering phenomenon. Even when trying to embed clay, alumina, and fibers into the slits of the Si-SiC shelf, the Si-SiC shelf has a large surface smoothness.
Could not be embedded. Accordingly, an object of the present invention is to provide a Si-SiC shelf manufactured by embedding a specific substance in a slit of the Si-SiC shelf.

[0005]

That is, according to the present invention, a shelf board made of a Si-SiC sintered body containing at least SiC and Si as constituents and provided with slits or grooves for stress relaxation. a is, the slit or groove embed a metal Si Mutotomoni, embedded metal Si
Is characterized in that microcracks occur during firing .

[0006]

The present invention is characterized in that metal Si is embedded in the slit of the Si-SiC shelf. Such a shelf board is high in strength, excellent in oxidation resistance, creep resistance and spalling resistance, and can increase the amount of objects to be fired such as ceramics and the like, and further improve the durability. Efficiency is improved. Further, it does not cause a break or explosion phenomenon of the shelf, and is preferably used as a shelf for a firing furnace. In the shelf board of the present invention, metal Si is used as a filler for embedding the slit. The metal Si has good adhesiveness to the Si-SiC shelf and can appropriately embed the slit.
Further, even when the slit is filled with metal Si, the metal Si itself is fragile, so that microcracks easily occur during firing, and a stress relaxation effect is brought about.

Next, a description will be given of a method of manufacturing a Si-SiC shelf according to the present invention in which metal Si is embedded in a slit. First, a raw material containing SiC powder, an organic binder and water or an organic solvent, and further containing carbonaceous powder, if necessary, is used as a raw material for molding. After kneading the forming raw material, a formed body having slits or grooves is formed. Here, the slits and grooves may be formed during or after molding. Next, the compact is placed in a reduced pressure inert gas atmosphere or vacuum under a metallic silicon atmosphere to impregnate the compact with metallic silicon and simultaneously fill the slits or grooves with metallic silicon to form Si-Si.
Manufacture C shelf.

The molding method of the present invention can be any of press molding, cast molding, and extrusion molding. However, slits or grooves can be formed simultaneously, and mass production is excellent. Press molding is preferred. As the press molding, a hydraulic press is preferable. The hydraulic press pressure is usually 50-2000kgf /
Use cm ² .

The slit in the present invention preferably has a predetermined length. That is, the slit is formed from the edge of the shelf to the edge opposite to the edge, and the slit length is in the range of 15 to 35% of the length of each edge of the shelf, particularly in the range of 20 to 30%. It is preferred that When the slit length is within the above range, the explosion does not occur, and the breakage of the shelf is suppressed as much as possible.

[0010]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. In on a sintered body by placing the 50% area fraction of the thickness 20mm alumina brick (spalling resistance (△ T) Evaluation method), atmospheric from the furnace constant temperature T ₂ (T ₁₎ Crack or explosion occurs when pulled out. ΔT (= T ₂ −T
₁ ) Measured.

(Evaluation method for creep resistance) 110 mm × 2
A test piece of 0 mm × 5 mm (thickness) was cut out and supported from below at intervals of 100 mm as shown in FIG. 2, and a load of 300 kgf / cm ² was applied downward from the center at 1350 ° C. in the atmosphere, and The amount of deformation during 100 hours was measured. (Oxidation resistance evaluation method) The sintered body was heated at 1050 ° C for 100 hours.
r, placed in a gas of H ₂ O + O ₂ , and increase the amount (△ W)
Was measured.

Example 1 SiC fine powder having an average particle size of 5.0 μm and an average particle size of 100 μm
Of SiC coarse powder mixed at 35:65 (weight ratio)
5.0 wt% of carbonaceous powder having an average particle diameter of 1.5 μm, 1.0 wt% of an organic binder (methylcellulose), and 5.0 wt% of water or an organic solvent are externally blended with the C powder and molded. Raw material was obtained. Next, after these raw materials for forming are crushed using a ball mill, the crushed raw materials for forming are introduced into a mold, and are formed at 400 kgf / cm ² using a hydraulic press, and the thickness is 5 mm, 10 mm. Various plate-shaped molded articles (400 mm × 350 mm) having no slit and having four slits as shown in FIG. 1 were obtained. The slits 10 and 11 provided in parallel with the 400 mm side of the plate-shaped molded product were each 1 slit.
Slit 1 provided with a length of 00mm and parallel to 350mm side
2 and 13 each had a length of 90 mm.

Next, a plate-shaped compact and 50% by weight of metal Si of the compact are placed in a carbon crucible provided with a reaction preventing layer of BN (boron nitride) coating, and 0.1 Torr from room temperature to 600 ° C. Under vacuum of 600-100
During 0 ° C., under a 2 Torr argon gas atmosphere,
By sintering under a reduced pressure of 5 Torr in an argon gas atmosphere up to 1800 ° C., a Si—SiC sintered body without a slit and Si—S in which metal Si is embedded in the slit.
An iC sintered body was manufactured. The holding time at the maximum temperature (1800 ° C.) was 2 hours. Moreover, 1400-1500 degreeC
The temperature was raised at 10 ° C./hr during the period. The bending strength, spalling resistance (ΔT), creep resistance and oxidation resistance (ΔW) of the obtained Si—SiC sintered body were evaluated. Table 1 shows the results.

[0014]

[Table 1]

As is clear from Table 1, the Si—SiC sintered body in which the slit is provided and the metal Si is embedded therein has a larger ΔT than the Si—SiC sintered body without the slit, and has a lower spalling resistance. It turned out to be excellent. Further, it can be seen that the bending strength is large, and the creep resistance and oxidation resistance are also excellent.

[0016]

As described above, according to the shelf board of the present invention, since the strength is large, the amount of the object to be fired can be increased, and the shelf board is excellent in spalling resistance, creep resistance and oxidation resistance. Things. Accordingly, the shelf plate of the present invention is a shelf plate for a rapid firing furnace, which emphasizes spalling resistance, creep resistance and oxidation resistance, a kiln tool such as a sagger, a saya, etc., particularly for tile firing using a roller hearth kiln. It can be preferably used for a shelf board.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of a shelf plate with slits.

FIG. 2 is an explanatory diagram showing an example of a creep evaluation test of an example.

[Explanation of symbols]

 10,11,12,13 slit

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C04B 35/64-35/65 C04B 35/565-35/577

Claims (1)

(57) [Claims] 1. A shelf plate comprising a Si-SiC sintered body containing at least SiC and Si as constituents, and provided with slits or grooves for stress relaxation, wherein said slits or grooves are made of metal Si. embedding Mutotomoni, embedded
A Si-SiC shelf , wherein micro-cracks are generated when metal Si is fired .