JP3131066B2 - Jig for firing ceramic products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention, on the surface of the base material of the sagger and shelves such as ceramics products firing jig to form a coating layer of yttria stabilized zirconia _{(ZrO 2 / Y 2 O 3} ) The present invention relates to a jig for firing ceramic products.

[0002]

2. Description of the Related Art Conventionally, firing jigs such as saggers and shelves have been used for firing various ceramic products such as tiles, sanitary ware, tableware and electronic components. For example, when manufacturing an electronic component such as a ceramic capacitor, there is a process of firing the base of the electronic component at 1200 to 1400 ° C., and a jig such as a sagger or a shelf plate conventionally used in this process is used. It is said that ZrO ₂ is preferable as a material that has the least reaction with the electronic component in a portion that comes into contact with the electronic component. Therefore, a method of coating ZrO ₂ on the surface of the base material of the jig is considered. Is being done.

The above-mentioned ZrO ₂ coating method includes a method using only ZrO _{2 for the} entire coating layer, and a method in which a ZrO ₂ coating is applied between the base material of the jig and the ZrO ₂ coating layer.
l ₂ O ₃ or the like and a method of providing an intermediate layer has been performed by, as a stabilizer of ZrO ₂ in this case, CaO is used (KOKOKU 3-586, JP-3-7765
No. 2).

[0004]

However, in the above-mentioned prior art, the entire coating layer is made of ZrO.
_When only ₂ is used, it is expensive, and the base material of the firing jig and Z
when an intermediate layer of Al ₂ O ₃ or the like between the coating layer and rO _2, the jig base member, may be peeled off from each other by difference in thermal expansion coefficient between the intermediate layer and the coating layer is there.

When CaO is used as a stabilizer for ZrO ₂ , for example, the base material of an Al ₂ O ₃ jig is
When aO-stabilized zirconia is sprayed, CaO diffuses little by little into the base material at high temperature, so the CaO amount in the coating layer gradually decreases, and ZrO ₂ comes out of the stabilization region and is accompanied by heating and cooling. There is a problem that abnormal expansion and contraction may gradually appear and peel off. The present inventor formed an oxide layer containing Y ₂ O ₃ on the surface of a jig for firing a ceramic product , and formed a Y layer on the oxide layer.
The content of ₂ O ₃ is adjusted between the substrate side and the surface of the oxide layer.
By changing continuously , the conventional problem is solved,
The inventors have found that a coating layer having good performance can be formed, and have reached the present invention.

[0006]

That is, according to the present invention, in a jig used for firing a ceramic product, a coating layer containing Y ₂ O ₃ is formed on a surface of a base material of the jig. And the coating layer
The content of Y ₂ O ₃ is determined from the side of the substrate to the surface of the coating layer.
Provided is a jig for firing a ceramic product, wherein the jig continuously changes between the surfaces . In the present invention
Means that the coating layer further contains a filler.
preferable. Further, the content of Y ₂ O ₃ of the total the coating layer is preferably not more than 25 wt%.

[0007]

According to the present invention, the coating layer is contained Y ₂ O _3, and, of Y ₂ O ₃ in the coating layer
Content from the substrate side to the surface of this coating layer
The coating layer is controlled to change continuously, so that the coating layer is more difficult to peel from the substrate, and the peel resistance is further improved.
It is possible to improve on. Moreover, the separation resistance can be improved while maintaining the reaction resistance and spall resistance with the object to be fired in a favorable state.

Next, the firing jig of the present invention will be described in detail. The firing jig of the present invention is formed by forming a coating layer containing Y ₂ O ₃ on a substrate. Here, the substrate is not particularly limited, but Al ₂ O ₃ , SiO ₂ , Al ₂ O ₃ , SiO ₂ , MgO
System, SiC, SiO ₂ system, SiC, Si ₃ N ₄ system and the like. The content of Y ₂ O ₃ is preferably controlled to 25% by weight or less based on the whole coating layer.

The components other than Y ₂ O ₃ include ZrO ₂ and M
gO and the like. In this case, the conventional CaO
Compared with a coating layer using stabilized ZrO ₂ (ZrO ₂ / CaO), Y ₂ O ₃ stabilized ZrO ₂ (ZrO ₂ / Y
It is considered that the coating layer using ₂ O ₃ ) is less likely to be solid-dissolved at a high temperature, has excellent peeling resistance, and is better as a coating layer for a firing jig.

On the other hand, in the firing jig of the present invention, the content of Y ₂ O _{3 in} the coating layer is controlled so as to continuously change from the substrate side to the surface of the coating layer. . By controlling as described above, the peeling resistance can be improved. As a method of changing this, Y _{2 is set in} the direction from the substrate side to the surface side.
It is preferable that the content of O ₃ is gradually increased. At this time, Y at the portion of the coating layer that is in contact with the substrate surface (ie, the lowermost surface of the coating layer)
The content of ₂ O ₃ may be 0%. In addition, Y ₂ in the portion (top surface) of the coating layer that contacts the object to be fired.
The O ₃ content may be 100%.

Further, the coating layer according to the firing jig of the present invention may contain a filler such as Al ₂ O ₃ or mullite in addition to Y ₂ O ₃ or ZrO ₂ . For example, Al ₂
By containing O _3, it is possible to improve the conformability (affinity) of Y ₂ O ₃ and ZrO _2, the result, it is possible to improve the peeling resistance of the tool. Moreover, by incorporating these fillers into the coating layer, the content of expensive Y ₂ O ₃ can be reduced, which is advantageous in cost.

Next, a method of manufacturing the firing jig of the present invention will be described. First, an ordinary method can be applied as a method for producing a substrate. That is, a predetermined raw material powder may be mixed and molded, and then fired. On the other hand, as a method for producing the coating layer according to the present invention, a thermal spraying method can be mentioned. As the thermal spraying method, plasma spraying is preferable in consideration of the melting point of ZrO ₂ or the like, and water plasma spraying is more preferable.

[0013]

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. ( Reference Example 1) Al ₂ O ₃ 9 having dimensions of 295 × 295 × 10 mm (thickness)
0 wt%, the surface of the refractory base material containing SiO ₂ 10 wt%, water ZrO ₂ / Y ₂ O ₃ powder particle size 10~45μm (ZrO ₂ 94 wt% / Y ₂ O ₃ 6 wt%) It was sprayed to a thickness of 0.8 mm by a plasma spraying device. Peeling resistance,
The reaction resistance and spall resistance were evaluated, and the results are shown in Table 1.

Reference Examples 2 and 3 Thermal spraying was performed in the same manner as in Reference Example 1 except that the mixing ratio of ZrO ₂ and Y ₂ O ₃ was changed as shown in Table 1. Table 1 shows the results. (Comparative Example 1) Thermal spraying was performed in the same manner as in Reference Example 1 except that ZrO ₂ / CaO powder was used at a mixing ratio as shown in Table 1. Table 1 shows the results.

[0015]

[Table 1] From the above reference examples 1 to 3 and comparative example 1 , Z
Those using rO ₂ / Y ₂ O ₃ have performance (particularly peel resistance)
It can be seen that the performance using ZrO ₂ / CaO is inferior in performance.

Embodiment 1 FIG. 1 is a schematic explanatory view of the preparation of a coating material and a coating method. First, ZrO ₂ / Y ₂ O ₃ (ZrO ₂ : 9
4 wt%, Y ₂ O _3: were prepared 6 wt%) of the # 325F powder 65 parts by weight # 1500F powder 35 parts by weight. on the other hand,
In the raw material tank 1, the ZrO ₂ / Y ₂ O ₃ mixed powder 10
30 parts by weight of water and 3 parts by weight of methyl cellulose (binder) were mixed and stirred with 0 part by weight to prepare a binder liquid. Next, while stirring the obtained binder liquid at about 300 rpm, the prepared ZrO ₂
/ Y ₂ O ₃ powder was put into the raw material tank 1 and stirred for about 3 hours to produce a ZrO ₂ / Y ₂ O ₃ slurry.

Meanwhile, prepare the a # 1500F powder 50 parts by weight # 325F powder 50 parts by weight of Al ₂ O _3, then with respect to the Al ₂ O ₃ mixed powder 100 parts by weight, of 50 parts by weight of water and 3 weight Parts of methylcellulose (binder) were charged into the raw material tank 2 and stirred to prepare a binder liquid. Then, while stirring this binder liquid at about 300 rpm, the prepared Al ₂ O ₃ mixed powder was added, and the mixture was stirred for about 3 hours to produce an Al ₂ O ₃ slurry.

Next, a ZrO ₂ / Y ₂ O ₃ slurry and Al
_{The 2} O ₃ slurry was sent to the air gun 7 while controlling the respective supply amounts using the flow control valves 3 and 4. The weight ratio of ZrO ₂ / Y ₂ O ₃ : Al ₂ O ₃ from the SiC substrate 5 side toward the coating layer surface 6 is 0:10 as shown by the straight line A in FIG.
Coating was performed until the thickness was reduced to 1 mm without heat treatment using the air gun 7 so as to continuously change from 0 to 100: 0. Next, after drying at 100 ° C. for 8 hours, baking was performed at a maximum temperature of 1400 ° C. for 2 hours. The same performance evaluation as above was performed on the obtained firing jig, and the results are shown in Table 2.

(Example 2 ) The supply amounts of the above-mentioned slurries were appropriately controlled by the flow control valves 3 and 4, and as shown by the line B in FIG. 2, ZrO ₂ / Y
The weight ratio of ₂ O ₃ : Al ₂ O ₃ is 10:90 and the thickness is 0.2 mm
After coating to a thickness of 0.2mm to 0.
Up to 7 mm, the weight ratio of ZrO ₂ / Y ₂ O ₃ : Al ₂ O ₃ is 1
Coating was performed while continuously changing from 0:90 to 95: 5, and then coating was performed at a weight ratio of ZrO ₂ / Y ₂ O ₃ : Al ₂ O ₃ of 95: 5 to a thickness of 1.0 mm. . Except for the above, all operations were the same as in Example 1, and the results obtained are shown in Table 2. Example 3 As shown by the line C in FIG. 2, ZrO ₂ / Y ₂ O ₃ : Al ₂ O ₃
Was carried out in the same manner as in Example 1 except that the weight ratio was 50:50. Table 2 shows the results. Except that performed (Example 4) coated only with ZrO ₂ / Y ₂ O ₃ was carried out in the same manner as in Example 1. Table 2 shows the results.

(Comparative Example 2) All of Example 1 except that coating was performed only with ZrO ₂ / CaO (ZrO ₂ : 93% by weight, CaO: 7% by weight).
The same was done. Table 2 shows the results.

[0021]

[Table 2]

From the results of Examples 1 to 4 and Comparative Example 2, it can be seen that in the case of Examples 1 to 4 relating to the firing jig of the present invention, the performance of the coating layer is good. Also,
It can also be seen that by mixing Al ₂ O ₃ and continuously changing the ratio of ZrO ₂ / Y ₂ O ₃ , the peeling resistance of the coating layer is further improved.

The method of evaluating the performance of the coating layer shown in Tables 1 and 2 will be described below. (1) In the peeling resistance test, a ceramic capacitor was placed on the firing jig obtained in each example, the temperature was raised at 200 ° C./hr, the temperature was held at 1300 ° C. for 1 hour, and then cooling was performed. Under the kiln conditions, the evaluation was performed by the number of kiln passes until the coating layer was separated from the refractory substrate. On this occasion,
◎: 20 or more passes, ○: 10 to less than 20
、 ５: 5 times or more and less than 10 times were marked with △, and less than 5 times were marked with x.

(2) In the reaction resistance test, after passing through the kiln three times under the same conditions as the above-mentioned kiln, the state of the solid solution of the coating layer was investigated. At this time, those without de-solid solution were marked with ◎, those with slight de-solid solution were marked with ○, those with severe de-solid solution were marked with Δ, and those with completely de-solid solution were marked with x. (3) The spall resistance was determined by using the firing jig obtained in each example as 1
A test piece was processed into a test piece of 50 × 150 × 10 mm (thickness), and two 90 × 90 × 3 mm (thickness) ZrO ₂ setters were placed on the test piece and placed on a roller hearth at a temperature of 600 ° C. The sample was placed in a furnace for 30 minutes, taken out, and cooled to room temperature. At this time, the evaluation was performed by the number of times of the kiln where cracks occurred in the test piece. At this time, the number of times of passing through the kiln 10 or more was marked with a circle.

[0025]

As described above, according to the present invention,
Since the surface of the jig for firing ceramic products was coated with an oxide layer containing Y ₂ O ₃ , the coating layer was improved in peel resistance, spall resistance and reaction resistance, and was equipped with a stable coating layer. The firing jig can be provided, and the article to be fired can be suitably fired.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of adjustment of a coating material and a coating method.

FIG. 2 is an explanatory diagram showing a composition change of a coating material.

[Explanation of symbols]

1 ZrO ₂ / Y ₂ O ₃ tank 2 Al ₂ O ₃ tank 3 flow regulating valve 4 flow control valve 5 substrate 6 coated layer surface 7 air gun

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-5-270925 (JP, A) JP-A-5-296671 (JP, A) JP-A-6-219872 (JP, A) JP-A-6-198772 219873 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C04B 35/64 F27D 3/12

Claims (2)

(57) [Claims] 1. A jig used for firing a ceramic product , wherein a coating layer containing Y ₂ O ₃ is formed on the surface of a base material of the jig , and the coating layer
The content of the Y ₂ O ₃ in
A jig for firing a ceramic product, wherein the jig changes continuously up to the surface of the coating layer . 2. The jig for firing a ceramic product according to claim 1, wherein the coating layer further contains a filler.