JP6628037B2 - Work firing method - Google Patents

Description

  The present invention relates to a work baking method, and more particularly, to a work baking method for continuously baking a work.

  2. Description of the Related Art There has been known a method of firing a workpiece by continuously transporting a firing jig on which an unfired workpiece is placed and passing the jig through a firing furnace.

  For example, Patent Document 1 discloses a method of firing a work using a firing jig called a sheath.

  FIG. 7 is an assembled perspective view of the sheath 120. As shown in FIG. 7, the sheath 120 is made of an alumina ceramic bottom plate member 121 having substantially L-shaped projections 122 at the four corners, and an alumina ceramic bottom plate 123 having substantially L-shaped notches 123 fitted into the respective projections 122. Frame member 124. A window 125 is provided on the upper surface of the frame member 124 to ensure the flow of air between the outside and the inside.

  FIG. 8 is an explanatory diagram of the trolley 130. As shown in FIG. 8, a plurality of ceramic green compacts used for, for example, an electronic component, a gas sensor element, or a plug are arranged in the sheath 120, and the sheath 120 is placed on a ceramic base plate 126. Are stacked in two stages via a frame 127 to form a shed mounted carriage 130. The side surface of the base plate 126 of the sheath mounting cart 130 is pushed into the entrance of the firing furnace 110 with a pusher for about 35 minutes. By repeatedly pushing the trolley 130, the trolley 130 moves in the baking furnace 110 and exits from the baking furnace 110 after a lapse of a predetermined time.

  Patent Literature 2 discloses a firing jig called a shelf having a porous coating layer formed on the surface by spraying mullite.

Japanese Patent Application Laid-Open No. H11-211363 JP-A-2014-6031

  When firing a work (objects to be fired, including unfired compacts, arranged in a firing jig) by continuously transporting the firing jig and passing through the firing furnace, the firing jig is used in the firing furnace. When the density of the jig is increased, productivity can be improved. Therefore, it is conceivable that adjacent firing jigs are in contact with each other.

  However, when the adjacent firing jigs are in contact with each other, depending on the firing jigs, that is, in a certain kind of saya, when used repeatedly for sintering, the sayas in contact with each other stick (adhere to each other). There is. If the sheaths adhere to each other, there is a danger that the sheaths may be clogged in the firing furnace, or the work may be spilled from the sheaths, and may cause a great deal of damage. In addition, the life of the sheath itself is shortened.

  The present invention has been made in view of the above circumstances, and has as its object to provide a method of firing a work that can prevent sticking of the sheaths in contact with each other. The above-mentioned sticking of the sheaths is a phenomenon newly found by the inventor of the present invention, and the subject of the present invention itself is new.

  The present invention provides a method for firing a workpiece configured as follows in order to solve the above problems.

  The method of firing the work includes: (i) a preparation step of preparing a sheath on which the work is placed; and (ii) a plurality of the sheaths on which the work is placed are continuously conveyed and passed through a firing furnace. Transporting step. At least a part of the sheath is (a) an element body containing SiC, and (b) a plurality of surfaces of the element body, the first surface facing the sheath adjacent in the conveying direction of the sheath in the conveying step in the conveying step. And a first ceramic coating layer formed on at least a part of the surface of the first ceramic coating. In the carrying step, the plurality of sheaths adjacent to each other in the carrying direction are brought into contact with each other via the first ceramic coating layer.

  The work placed on the sheath in the preparation step of the above method is an object to be fired including an unfired compact.

  When the sheath body contains SiC (silicon carbide), if the sheath is repeatedly used for firing, vitreous is formed in a portion where the body is exposed, and the sheaths adhere to each other through the vitreous material. Sometimes. Vitreous is caused by a reaction between impurities floating from the inside of the firing furnace or impurities generated from metal chips or heat insulating material chips deposited in the firing furnace and Si components of the element body.

  According to the above method, the first ceramic coating layer does not react (fuse) even when in contact with the vitreous material. Thereby, even if the first ceramic coating layer contacts the vitreous material, the sheaths that are in contact with each other via the first ceramic coating layer can be prevented from sticking to each other.

  In the transporting step, a gap is formed by the first ceramic coating layer between the body elements of the sheath adjacent to each other in the transport direction. Since the amount of vitreous formed in a portion where the elementary body is exposed is limited, if the gap between the elementary bodies adjacent to each other is a certain distance or more, the elementary bodies adjacent to each other are interposed via the glassy substance. it dose not connect. Thereby, it is possible to prevent adjacent element bodies from sticking to each other.

  Therefore, it is possible to prevent the sheaths that are in contact with each other in the transport direction from sticking to each other.

  Preferably, the at least a part of the sheath is formed on at least a part of a second surface of the plurality of surfaces of the element body facing the sheath in a direction orthogonal to the transport direction in the transport step. Further provided is a second ceramic coating layer provided. In the carrying step, the plurality of sheaths adjacent to each other in the direction orthogonal to the carrying direction are brought into contact with each other via the second ceramic coating layer.

  In this case, it is possible to prevent sticking of the sheaths that are in contact with each other in a direction perpendicular to the transport direction, similarly to the sheaths that are in contact with each other in the transport direction.

Preferably, the first ceramic coating layer contains at least one of alumina, zirconia, magnesium oxide (MgO), and yttrium oxide (Y ₂ O ₃ ) as a main component.

  In this case, the first ceramic coating layer that does not react (fuse) with the vitreous material can be formed. In addition, about zirconia, stabilized zirconia is preferable, for example, Y stabilized zirconia and Ca stabilized zirconia are preferable.

  Preferably, the thickness of the first ceramic coating layer is 50 μm or more.

  In this case, it is possible to sufficiently secure a gap between the bodies of the sheaths adjacent to each other in the transport direction, and it is possible to reliably prevent sticking of the sheaths that are in contact with each other in the transport direction. Further, even if the first ceramic coating layer is worn and its thickness is reduced, an effect of preventing sticking can be obtained for a long time.

  In a preferred aspect, a plurality of the first ceramic coating layers are formed on the first surface of the body of the sheath at intervals from each other.

  In this case, the number of coating materials for forming the first ceramic coating layer can be reduced as compared with the case where the first ceramic coating layer is formed so as to cover the entire first surface of the body.

  In another preferred aspect, the first ceramic coating layer covers the entire first surface of the body.

  In this case, it is possible to reliably prevent sticking with other sheaths adjacent in the transport direction.

  ADVANTAGE OF THE INVENTION According to this invention, sticking of the sheaths which contact mutually can be prevented. Since the sheath can be transported at a high density in the firing furnace by using the sheath having a small warp and containing SiC, productivity can be improved. In addition, the life of the sheath itself is prolonged.

FIG. 1 is an explanatory view schematically showing a cross section of the firing furnace. (Example 1) FIG. 2 is an explanatory view of the firing furnace as viewed from above. (Example 1) FIG. 3 is an explanatory diagram of the sheath. (Comparative Example 1) FIG. 4 is an explanatory diagram of the sheath. (Example 1) FIG. 5 is an explanatory diagram of the sheath. (Example 2) FIG. 6 is a side view of the sheath. (Modifications 1 to 4 of Embodiment 2) FIG. 7 is an assembled perspective view of the sheath. (Conventional example 1) FIG. 8 is an explanatory view of a trolley mounted trolley. (Conventional example 1)

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  Example 1 A method of firing a work according to Example 1 will be described with reference to FIGS. In the method of firing a workpiece according to the first embodiment, a sheath having a ceramic coating layer formed on the entire side surface of the element body is used.

  FIG. 1 is an explanatory diagram schematically showing a configuration of a firing furnace 10 used for firing a work. FIG. 2 is an explanatory view of the firing furnace 10 as viewed from above.

  As shown in FIG. 1, in the firing furnace 10, a heater 16 is disposed in an internal space 12 surrounded by a heat insulating material 14. In the interior space 12 of the firing furnace 10, and near the inlet 11a and the outlet 11b, rollers 18 for supporting the sheath 20 are arranged.

  The sheath 20 on which the unfired work (not shown in FIGS. 1 and 2) is placed is put into the internal space 12 from the inlet 11a of the firing furnace 10, and is taken out from the outlet 11b. While the sheath 20 moves in the internal space 12, the unfired work is fired.

  For example, the rollers 18 are configured to be rotatable, and the sheaths 20 are continuously conveyed by pushing the sheaths 20 one after another from the entrance 11 a of the firing furnace 10. The roller 18 may be rotationally driven by a motor to continuously transport the sheath 20.

  The sheath 20 may convey only one row, but may convey a plurality of rows (three rows in FIG. 2) simultaneously as shown in FIG. When the density of the sheaths 20 is increased in the firing furnace 10, productivity is improved, so that the adjacent sheaths 20 are in contact with each other.

  FIG. 3 is an explanatory diagram of the sheath 20g of Comparative Example 1. As shown in FIG. 3, in the sheath 20g, the whole of a pair of main surfaces facing each other of the rectangular flat body 20k is covered with ceramic coating layers 20s and 20t. A pair of opposite side surfaces 20p (only one is illustrated) of the element body 20k and another pair of opposite side surfaces 20q (only one is illustrated) are exposed to the outside.

As the element body 20k, a ceramic substrate of alumina, mullite, SiC or the like can be used. The ceramic coating layers 20 s and 20 t are for preventing a reaction (fusion) when the workpiece 2 such as a chip raw body is placed on the sheath 20 and for preventing the sheath 20 from warping. The ceramic coating layers 20s and 20t are made of alumina coating, zirconia (ZrO ₂ ) coating partially stabilized with Y or Ca, or the like.

  When the body 20k of the sheath 20g of Comparative Example 1 is a SiC-based ceramic, when the sheath 20g is repeatedly used for firing, the side 20p, 20q of the body 20k is schematically illustrated by a black oval in FIG. Is formed, and the sheaths 20g adjacent to each other may stick together (adhere to each other) via the glassy 4.

  This phenomenon has been newly discovered by the present inventor. The inventor of the present application has proposed that the vitreous material is formed by reacting impurities generated from metal chips or heat insulating material particles floating or deposited in the internal space of the firing furnace 10 with Si components contained in the body 20k of the sheath 20g. 4 was formed, and as described below, a method of firing a workpiece using a sheath having a ceramic coating layer on the side surface of a body 20k containing SiC was invented.

  FIG. 4 is an explanatory diagram of the sheath 20a. As shown in FIG. 4, the sheath 20 a includes ceramic coating layers 20 s and 20 t respectively covering the entire pair of opposing rectangular main surfaces of a rectangular flat body 20 k containing SiC. A ceramic coating layer 20r is formed to entirely cover the pair of opposed side surfaces 20p and the other pair of opposed side surfaces 20q.

The method of forming the ceramic coating layer 20r is not particularly limited, such as a method of spraying or a method of applying the composition by spraying and then baking. The ceramic coating layer 20r does not react (fuse) with the vitreous material 4, for example, a material mainly containing at least one of alumina, zirconia, magnesium oxide (MgO), and yttrium oxide (Y ₂ O ₃ ). To form As for zirconia, stabilized zirconia is preferable, and for example, Y-stabilized zirconia and Ca-stabilized zirconia are preferable.

  Next, a method of firing a work using the sheath 20a will be described.

  First, as a preparation step, a sheath 20a on which the unfired work 2 is placed is prepared.

  Next, as a transporting step, the plurality of sheaths 20a on which the unfired work 2 is placed are continuously transported and passed through the firing furnace 10 (see FIG. 1). In this transporting step, the plurality of sheaths 20a are arranged and transported in one or more rows, and the plurality of sheaths 20a adjacent to each other in the transport direction of the sheath 20a are brought into contact with each other via the ceramic coating layer 20r.

  Of the ceramic coating layer 20r, in the carrying step, in the carrying step, the portion interposed between the bodies 20k of the sheath 20a adjacent to each other in the carrying direction, that is, the portion formed on the side surface 20p or 20q of the body 20k, In Example 1, it corresponds to a “first ceramic coating layer”. In the transporting step, the opposing side surfaces 20p or 20q of the element bodies 20k of the sheath 20a adjacent to each other in the transport direction correspond to a “first surface” of the element body 20k in the first embodiment.

  According to the above method, since the element body 20k is not exposed, even if the sheath 20a is repeatedly used for firing, the vitreous material 4 (see FIG. 3) resulting from the reaction with the Si component contained in the element body 20k is formed. Not done. Since the vitreous material 4 (see FIG. 3) does not intervene between the sheaths 20a, it is possible to reliably prevent the sheaths 20a that are in contact with each other in the transport direction from sticking to each other.

  In the transporting step, when a plurality of sheaths 20a are transported in two or more rows as shown in FIG. 2, a plurality of sheaths 20a adjacent to each other in a direction orthogonal to the transport direction are brought into contact with each other via a ceramic coating layer 20r. Let it. In this case, like the sheaths 20a that contact each other in the transport direction, it is possible to prevent the sheaths 20a that contact each other in the direction perpendicular to the transport direction from sticking to each other.

  Of the ceramic coating layer 20r, a portion interposed between the element bodies 20k of the sheath 20a adjacent to each other in a direction orthogonal to the conveyance direction in the conveyance step, that is, a part formed on the side surface 20p or 20q of the element body 20k. This corresponds to the “second ceramic coating layer” in the first embodiment. In the transporting step, the opposing side surfaces 20p or 20q of the element bodies 20k of the sheath 20a adjacent to each other in a direction orthogonal to the transport direction correspond to the “second surface” of the element body 20k in the first embodiment. Equivalent to.

  The sheath 20a can reliably prevent the adjacent sheaths from sticking to each other by the ceramic coating layer 20r that covers the entire side surfaces 20p and 20q of the element body 20k. Therefore, if at least a part of the plurality of sheaths used for baking the work is the sheath 20a, it is possible to prevent sticking of the sheaths that are in contact with each other.

  For example, in the transporting step, even if the sheaths 20a in FIG. 4 and the sheaths 20g in FIG. 3 are alternately arranged and transported so as to be in contact with each other, it is possible to prevent the sheaths 20a and 20g in contact with each other from sticking to each other. This is because the ceramic coating layer 20r of the sheath 20a does not react (fuse) with the vitreous material 4 even if the vitreous material 4 is formed in the exposed portion of the body 20k of the sheath 20g.

  <Example 2> A method of firing a workpiece of Example 2 using sheaths 20b to 20f in which a ceramic coating layer is formed on a part of the side surfaces 20p and 20q of the element body 20k will be described with reference to FIGS. I do. The second embodiment is substantially the same as the first embodiment. In the following, the same reference numerals are used for the same components as in the first embodiment, and the description will focus on differences from the first embodiment.

  FIG. 5 is an explanatory diagram of the sheath 20b. As shown in FIG. 5, the sheath 20b includes a rectangular plate-shaped element body 20k containing SiC, ceramic coating layers 20s and 20t respectively covering a pair of mutually opposed rectangular main surfaces of the element body 20k. It has ceramic coating layers 20u and 20v formed at two locations on each of a pair of opposing side surfaces 20p of the body 20k and another pair of opposing side surfaces 20q.

  FIG. 6 is a side view of the sheaths 20c to 20f of the first to fourth modifications of the sheath 20b of the second embodiment. As shown in FIG. 6, the positions, shapes, and numbers of the ceramic coating layers 20w to 20z formed on a part of the four side surfaces of the element body 20k can be appropriately selected.

  In the sheath 20c shown in FIG. 6A, two circular ceramic coating layers 20w are formed in the middle part of the side surface of the element body 20k at intervals.

  In the sheath 20d shown in FIG. 6B, two rectangular ceramic coating layers 20x are formed at both ends of the side surface of the element body 20k with an interval therebetween.

  In the sheath 20e shown in FIG. 6C, three rectangular ceramic coating layers 20x are formed in the middle part of the side surface of the element body 20k at intervals.

  The sheath 20f shown in FIG. 6D has three circular ceramic coating layers 20z with a space provided between the side surfaces of the body 20k and the ceramic coating layers 20s and 20t covering the main surface of the body 20k. Are formed at an interval from each other.

  The ceramic coating layer formed on a part of the side surface of the sheath body may have a shape other than a rectangular shape and a circular shape, or may be formed asymmetrically. For example, a ceramic coating layer may be formed on one end and an intermediate portion of the side surface of the body. Further, a ceramic coating layer may be formed on a side surface of the body so as to be in contact with only one of the ceramic coating layers covering the main surface of the body.

The method of forming the ceramic coating layers 20u to 20z on a part of the side surface of the element body is not particularly limited, such as a method of spraying or a method of baking after applying by spraying. The ceramic coating layer 20r does not react (fuse) with the vitreous material 4, for example, a material mainly containing at least one of alumina, zirconia, magnesium oxide (MgO), and yttrium oxide (Y ₂ O ₃ ). To form As for zirconia, stabilized zirconia is preferable, and for example, Y-stabilized zirconia and Ca-stabilized zirconia are preferable.

  Next, a method of firing a work using the sheaths 20b to 20f will be described.

  First, as a preparation step, sheaths 20b to 20f on which the unfired work 2 is placed are prepared.

  Next, as a transport step, the plurality of sheaths 20b to 20f on which the unfired work 2 is placed are continuously transported and passed through the firing furnace 10 (see FIG. 1). In this transport step, the plurality of sheaths 20b to 20f are arranged and transported in one or more rows, and the plurality of sheaths 20b to 20f adjacent to each other in the transport direction of the sheaths 20b to 20f are interposed via the ceramic coating layers 20u to 20z. Contact each other.

  Among the ceramic coating layers 20u to 20z, those that are interposed between the element bodies 20k of the sheaths 20b to 20f adjacent to each other in the conveyance direction in the conveyance step, that is, those that are formed on the side surfaces 20p or 20q of the element body 20k. Corresponds to the “first ceramic coating layer” in the second embodiment. Further, in the transporting step, the opposing side surfaces 20p or 20q of the element bodies 20k of the sheaths 20b to 20f adjacent to each other in the transport direction correspond to the “first surface” of the element body 20k in the second embodiment. .

  When the use of the sheaths 20b to 20f is repeated by the above method, the vitreous material 4 is formed in the portions of the sheaths 20b to 20f where the element body 20k is exposed. The ceramic coating layers 20u to 20z do not react (fusion) even when they come into contact with the vitreous material 4. Therefore, even if the ceramic coating layers 20u to 20z contact the vitreous 4, the sheaths 20b to 20f that are in contact with each other via the ceramic coating layers 20u to 20z do not stick to each other.

  In the transporting step, a gap is formed between the element bodies 20k of the sheaths 20b to 20f adjacent to each other in the transport direction by the ceramic coating layers 20u to 20z. The amount of the vitreous material 4 formed in a portion where the element body 20k is exposed is limited. If the gap between the element bodies 20k adjacent to each other is a certain size or more, the element bodies 20k adjacent to each other are made of glass. Not connected through quality 4. Therefore, it is possible to prevent the adjacent element bodies 20k from sticking to each other.

  Therefore, it is possible to prevent the sheaths 20b to 20f that are in contact with each other in the transport direction from sticking to each other.

  In the transporting step, when a plurality of sheaths 20b to 20f are arranged and transported in two or more rows as shown in FIG. 2, the plurality of sheaths 20b to 20f adjacent to each other in a direction orthogonal to the transport direction are separated from the ceramic coating layers 20u to 20u. Make contact with each other via 20z. In this case, like the sheaths 20b to 20f that contact each other in the transport direction, it is possible to prevent the sheaths 20b to 20f that contact each other in the direction perpendicular to the transport direction from sticking to each other.

  Of the ceramic coating layers 20u to 20z, in the transporting step, portions formed between the element bodies 20k of the sheaths 20b to 20f adjacent to each other in a direction orthogonal to the transport direction, that is, formed on the side surface 20p or 20q of the element body 20k. This corresponds to the “second ceramic coating layer” in the second embodiment. Further, in the transporting step, the opposing side surfaces 20p or 20q of the element bodies 20k of the sheaths 20b to 20f adjacent to each other in a direction orthogonal to the transport direction are the “second surface” of the element body 20k in the second embodiment. ".

  When the thickness of the ceramic coating layers 20u to 20z is increased to a certain degree or more, the effect of preventing the sheaths from sticking to each other can be surely obtained, and even if the ceramic coating layers 20u to 20z are worn and their thickness is reduced, they stick for a long time. The prevention effect is obtained.

  In addition, the sheaths 20b to 20f in which the ceramic coating layers 20u to 20z are formed on a part of the side surface of the body have a smaller amount of the coating material than the sheath 20a in which the ceramic coating layer 20r is formed on the entire side surface of the body. Is less, which leads to cost reduction.

  The plurality of sheaths used for firing may be only one type or a plurality of types among the sheaths 20b to 20f.

  Further, at least a part of the plurality of sheaths used for baking the workpiece may be the sheaths 20b to 20f. For example, in the transport step, any one of the sheaths 20b to 20f and the sheath 20g (see FIG. 3) may be transported so as to be alternately adjacent to each other. Also in this case, it is possible to prevent any one of the sheaths 20b to 20f that are in contact with each other from sticking to the sheath 20g.

  Also, the work 20 may be used in combination with the sheath 20a of the first embodiment and the sheaths 20b to 20f of the second embodiment. In this case, sticking between the sheaths 20b of the first embodiment and the sheaths 20b to 20f of the second embodiment that are adjacent to each other can be prevented.

  As in the case of the sheaths 20b to 20f of the second embodiment, if two or more ceramic coating layers are formed on the four side surfaces of the sheath at intervals, there is no need to align the orientation and the front and back of the sheath, and the work is easy. become.

  <Third Embodiment> Two or more ceramic coating layers may be formed at intervals on only one of the four side surfaces of the sheath body. Of the four side surfaces of the sheath body, two or more ceramic coating layers may be formed at intervals only on a pair of side surfaces facing each other. A ceramic coating layer may be formed on only one of the four side surfaces of the body of the sheath or only on a pair of side surfaces facing each other to cover the whole of each side surface. When using these sheaths in a method of firing a workpiece, in the carrying step, a plurality of sheaths adjacent to each other in the carrying direction are brought into contact with each other via a ceramic coating layer to prevent sticking of the sheaths that come into contact with each other in the carrying direction. be able to.

  <Example 4> Of the four side surfaces of the body of Saya, two or more ceramic coating layers may be formed at intervals only on two adjacent side surfaces or on only three side surfaces. Good. Of the four side surfaces of the body of the sheath, a ceramic coating layer may be formed on only two side surfaces adjacent to each other or on only three side surfaces to cover the whole of each side surface. When using these sheaths in a method of firing a workpiece, in the carrying step, a plurality of sheaths adjacent to each other in the carrying direction are brought into contact with each other via a ceramic coating layer to prevent sticking of the sheaths that come into contact with each other in the carrying direction. be able to. Further, in the transporting step, by preventing a plurality of sheaths adjacent to each other in the direction orthogonal to the transport direction from coming into contact with each other via the ceramic coating layer, it is possible to prevent sticking of the sheaths in contact with each other in the direction orthogonal to the transport direction. Can be.

<Production Example> Next, a production example of the sheath will be described. All of the samples of the fabrication examples were a Y-stabilized ZrO ₂ ceramic coating layer having a thickness of 100 μm on a pair of opposing rectangular main surfaces of a rectangular flat SiC body having a thickness of 2 mm and a size of 150 mm × 150 mm. Is formed.

Samples A to C have the same configuration as the sheath 20d in FIG. 6B, and a ceramic coating layer of ₂ mm × 2.5 mm Y-stabilized ZrO ₂ is formed on each of the four sides of the element body. I have. The thickness (target value) of the ceramic coating layer is 5 μm for sample A, 50 μm for sample B, and 100 μm for sample C.

Sample X has the same configuration as the sheath 20g in FIG. 3, and the ceramic coating layers are not formed on the four side surfaces of the element body. The sample Y has the same configuration as the sheath 20a in FIG. 4, and has a ceramic coating layer of Y-stabilized ZrO ₂ covering the entire side surface on each of the four side surfaces of the element body. The thickness (target value) of this ceramic coating layer is 50 μm.

  100 samples of each sample were prepared, and unfired chip components were placed on each sample, the sheath was flowed so that the side surfaces of the sheath in the transport direction were in contact with each other, and firing was repeated in a roller-type continuous furnace. Saya, who had stuck, was subsequently removed from the flow.

The following Table 1 shows the number of times of flow and the number of sticking sheets (cumulative value of the number of sheets removed from the flow).

  As shown in Table 1, in Sample X in which the ceramic coating layer was not formed on the side surface of the element body, sticking began to occur when the number of times of flow exceeded 200 times, and 72% of sheath was lost by 450 times. It became NG by sticking. Sample A, Sample B, Sample C, and Sample Y did not stick together up to 400 repetitions. From this, it is understood that the formation of the ceramic coating layer on the side surface of the body of the sheath can prevent the sheaths in contact with each other from sticking to each other.

  Sample A began to stick after more than 400 cycles. In Samples B and C, sticking did not occur even if firing was repeated 1000 times, similarly to Sample Y in which the coating layer was formed on the entire side surface of the element body.

  For this reason, the thickness of the ceramic coating layer formed on the side surface of the element is preferably 50 μm or more. In this case, it is possible to sufficiently secure a gap between the element bodies that are adjacent to each other in the transport direction, and it is possible to reliably prevent sticking of the sheaths that are in contact with each other in the transport direction. Further, even if the first ceramic coating layer is worn and its thickness is reduced, an effect of preventing sticking can be obtained for a long time.

<Summary> As described above, when the sheath having the ceramic coating layer formed on the side surface of the element body containing SiC is used, sticking of the sheaths in contact with each other can be prevented. Productivity can be improved because the sheath can be transported at a high density in a firing furnace using an elemental sheath made of SiC with little warpage or an elementary sheath made of SiC / Si ₃ N ₄ (nitride-bonded silicon carbide). Can be achieved. In addition, the life of the sheath itself is prolonged.

  The present invention is not limited to the above embodiment, and can be implemented with various changes.

  For example, although a square sheath is illustrated, the shape may be a rectangle or a trapezoid, and the shape of the sheath is not limited. The shape of the sheath is not limited to a flat plate shape, but may be a mortar shape (a ceramic coating layer is formed on a side surface). Further, a shape having a wall may be used.

2 Work 10 Firing furnace 20, 20a to 20g Saya 20k Element body 20p, 20q Side surface (first surface, second surface)
20r ceramic coating layer (first ceramic coating layer, second ceramic coating layer)
20s, 20t Ceramic coating layer 20u-20z Ceramic coating layer (first ceramic coating layer, second ceramic coating layer)

Claims (6)

A preparation process for preparing a sheath on which a work is placed;
A transporting step of continuously transporting the plurality of sheaves on which the workpieces are placed and passing the inside of the firing furnace,
In the method for firing a workpiece having
At least a part of the sheath is
A body containing SiC;
A first ceramic coating layer formed on at least a part of a first surface facing the sheath adjacent in the transport direction of the sheath in the transporting step, among the plurality of surfaces of the element body,
Has,
In the carrying step, a plurality of the sheaths adjacent to each other in the carrying direction are brought into contact with each other via the first ceramic coating layer, and a method of firing a workpiece. The at least a part of the sheath,
Of the plurality of surfaces of the body, a second ceramic coating layer formed on at least a part of a second surface facing the sheath in a direction orthogonal to the transfer direction in the transfer step,
Have more,
2. The workpiece according to claim 1, wherein, in the transporting step, a plurality of the sheaths adjacent to each other in the direction orthogonal to the transport direction are brought into contact with each other via the second ceramic coating layer. 3. Firing method.   3. The method according to claim 1, wherein the first ceramic coating layer contains at least one of alumina, zirconia, magnesium oxide, and yttrium oxide as a main component. 4.   4. The method according to claim 1, wherein the first ceramic coating layer has a thickness of 50 μm or more. 5.   The method according to any one of claims 1 to 4, wherein a plurality of the first ceramic coating layers are formed on the first surface of the body at intervals from each other. A firing method for the described work.   5. The method according to claim 1, wherein the first ceramic coating layer covers the entire first surface of the body. 6.

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