Heat treatment jig and method for manufacturing the same

Abstract

To provide a heat treatment jig in which a thermal-sprayed material sprayed onto a base material is less likely to peel off, and a method for manufacturing the heat treatment jig.SOLUTION: A heat treatment jig 10 includes a base material part 20 made of ceramics and a thermal-sprayed part 30 formed of a thermal-sprayed material. The base material part 20 has a thermal spray target region 22 onto which the thermal-sprayed material is sprayed, and the thermal spray target region 22 has a surface shape in which a sum of a core roughness depth Rk and a reduced peak height Rpk is greater than 15 μm and the reduced peak height Rpk is greater than 4.5 μm. The thermal-sprayed part 30 is formed by spraying the thermal-sprayed material onto the thermal spray target region 22 of the base material part 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a heat treatment jig and a method for manufacturing the heat treatment jig. [Background technology]

[0002] Conventionally, there have been provided heat treatment jigs and methods for manufacturing ceramic electronic components, such as those disclosed in Patent Document 1. The conventional technology disclosed in Patent Document 1 is capable of suppressing the diffusion of substances from the heat treatment object to the base material, and in order to perform stable heat treatment from the beginning of use, a first coating layer made of high-purity Al2O3 is disposed on a base material made of a mullite-based material, and a second coating layer mainly composed of ZrO2 is further disposed on the first coating layer, resulting in a multi-layer coating structure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-211991 Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of a configuration in which multiple coating layers are provided on a substrate, as in the prior art of Patent Document 1 mentioned above, if a coating layer peels off, there is a problem that a reaction between the substrate and the object to be heat-treated may occur, or the peeled coating layer may contaminate the object to be heat-treated.

[0005] As a result of intensive research, the inventors have discovered that by spraying the thermal spray material onto a substrate while optimizing the surface condition of the surface of the substrate onto which the thermal spray material is sprayed, the thermal spray material is less likely to peel off, and the occurrence of the above-mentioned problems can be suppressed.

[0006] Based on this finding, the present invention aims to provide a heat treatment jig in which the thermal sprayed material sprayed onto the substrate is less likely to peel off, and a method for manufacturing the heat treatment jig. [Means for solving the problem]

[0007] (1) The heat treatment jig of the present invention comprises a ceramic substrate and a sprayed portion formed of a spray material, the substrate having a spray target area onto which the spray material is sprayed, the spray target area having a surface shape in which the sum of the core level difference Rk and the protruding peak height Rpk is greater than 15 μm and the protruding peak height Rpk is greater than 4.5 μm, and the sprayed portion is formed by spraying the spray material onto the spray target area of ​​the substrate.

[0008] As a result of extensive research, the inventors have found that when the thermal spray material is sprayed onto an area that satisfies the first condition, that is, the sum of the core level difference Rk and the peak height Rpk is greater than 15 μm, the thermal spray material is less likely to peel off. Furthermore, as a result of extensive research, the inventors have found that when the thermal spray material is sprayed onto an area that satisfies the second condition, that is, the peak height Rpk is greater than 4.5 μm, the coating layer formed by the thermal sprayed portion 30 between adjacent peaks is slightly recessed, making it less likely to peel off. The present invention is based on this finding, and forms a thermal sprayed portion by spraying the thermal spray material onto an area that satisfies both the first and second conditions described above. Therefore, by adopting the configuration described in (1) above, the heat treatment jig of the present invention can provide a heat treatment jig in which the thermal sprayed material sprayed onto the substrate is less likely to peel off.

[0009] The heat treatment jig described above had a thermal spray strength of 3.5 [N / mm 2 ] or more.

[0010] The heat treatment jig of the present invention satisfies the above-mentioned conditions relating to peel strength, and therefore it is possible to provide a heat treatment jig in which the thermal sprayed material sprayed onto the substrate is less likely to peel off.

[0011] (2) In the heat treatment jig of the present invention, the region to be sprayed may be formed by pressing the raw material of the base material using a mold having a concave-convex shape corresponding to the surface shape, and then firing the resulting green compact.

[0012] By satisfying the condition (2) above, the heat treatment jig of the present invention can reliably and accurately prepare a substrate portion having the above-described surface shape in the thermal spraying target area. Therefore, by adopting the configuration according to (2) above, the heat treatment jig of the present invention can more reliably prevent the thermal spray material sprayed on the substrate from peeling off.

[0013] (3) In the heat treatment jig of the present invention, the base material may be formed from mullite ceramics, which is the fired product produced by firing a composition containing alumina and silica as main components.

[0014] By adopting the configuration according to (3) above, the heat treatment jig of the present invention can be provided as one made of mullite ceramics that has strength in high-temperature environments, and in which the thermal spray material is not easily peeled off.

[0015] (4) The method for manufacturing a heat treatment jig of the present invention is characterized by comprising: a substrate preparation step of preparing a substrate made of ceramics having a spray target area with a surface shape in which the sum of the level difference Rk of the core portion and the height Rpk of the protruding peaks is greater than 15 [μm] and the height Rpk of the protruding peaks is greater than 4.5 [μm]; and a thermal spraying step of spraying a thermal spray material onto the spray target area of ​​the substrate prepared in the substrate preparation step.

[0016] The manufacturing method for a heat treatment jig of the present invention is based on the finding that spraying a thermal spray material onto a region that satisfies the first condition that the sum of the core level difference Rk and the protruding peak height Rpk is greater than 15 μm, and the second condition that the protruding peak height Rpk is greater than 4.5 μm, as described above, makes the thermal sprayed portion less likely to peel off. The manufacturing method for a heat treatment jig of the present invention involves preparing a substrate that satisfies the first and second conditions described above in the substrate preparation step, and then spraying the thermal spray material onto this substrate in the thermal spraying step. Therefore, the manufacturing method for a heat treatment jig of the present invention can manufacture a heat treatment jig in which the thermal sprayed material sprayed on the substrate is less likely to peel off.

[0017] (5) In the method for manufacturing a heat treatment jig of the present invention, in the base material preparation step, the raw material of the base material is pressed using a mold having a concave-convex shape corresponding to the surface shape, and the green compact formed is then fired to prepare the base material having the thermal spray target area having the surface shape.

[0018] By satisfying the condition (6) above, the manufacturing method for a heat treatment jig of the present invention can reliably and accurately prepare a substrate portion in which the thermal spraying target area has the above-described surface shape. Therefore, by adopting the configuration according to (6) above, the manufacturing method for a heat treatment jig of the present invention can more reliably manufacture a substrate in which the thermal sprayed material is less likely to peel off, with a high yield. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a heat treatment jig and a method for manufacturing a heat treatment jig that solves the above-mentioned problems. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a cross-sectional view schematically showing a cross-sectional structure of a heat treatment jig according to an embodiment of the present invention. [Figure 2]1A and 1B are explanatory diagrams showing a schematic diagram of the relationship between the unevenness formed on the surface of the substrate in the thermal spraying target region and the load curve, where FIG. 1A is an explanatory diagram of the profile curve (smoothed roughness curve), and FIG. 1B is an explanatory diagram of the load curve. [Figure 3] 1A and 1B are schematic diagrams of a molding die used in a manufacturing method of a heat treatment jig according to one embodiment of the present invention, in which (a) is a cross-sectional view showing the molding die in an exploded state, and (b) is a cross-sectional view showing the molding die in an assembled state. [Figure 4] FIG. 1(a) is an exploded perspective view of a test piece used in an example according to the present invention, and FIG. 1(b) is a perspective view of the test piece. [Figure 5] FIG. 5 is a perspective view showing the test piece of FIG. 4 placed on a lower bending jig of a three-point bending tester. [Figure 6] FIG. 6 is a perspective view showing a state in which a pressing force is applied to the test piece set as in FIG. 5 by an upper bending jig while a measuring jig is also set thereon. DETAILED DESCRIPTION OF THE INVENTION

[0021] A heat treatment jig 10 according to one embodiment of the present invention and a method for manufacturing the heat treatment jig 10 will be described below.

[0022] <About Heat Treatment Jig 10> As shown in FIG. 1, the heat treatment jig 10 has a substrate portion 20 (substrate layer) and a thermally sprayed portion 30 (thermal sprayed layer). The substrate portion 20 is formed from a ceramic substrate and is formed in a layered form. The thermally sprayed portion 30 is a layer formed so as to cover a part or all of the surface of the substrate portion 20. When the heat treatment jig 10 is used, the thermally sprayed portion 30 is preferably provided at least in the area where the object to be heat treated is placed. The substrate portion 20 and the thermally sprayed portion 30 will be described in more detail below.

[0023] As described above, the substrate 20 is a layer formed from a ceramic substrate. The ceramic forming the substrate 20 can be, for example, inorganic compounds such as oxides, carbides, nitrides, and borides. The ceramic forming the substrate 20 can be appropriately selected taking into consideration thermal stability, mechanical strength, and the like. Specifically, the substrate 20 may be composed of one or more of silicon carbide, boron carbide, silicon nitride, boron nitride, aluminum nitride, alumina, yttria, zirconia, magnesia, mullite, and the like. Furthermore, the zirconia may be cubic zirconia or zirconia containing a mixture of cubic and tetragonal crystals. The substrate 20 may be, for example, a mullite ceramic containing mullite, among the aforementioned materials. The substrate 20 is formed by compressing raw material powder (raw material powder) to form a green compact, and then firing the green compact. The substrate portion 20 may be formed into an appropriate shape depending on the use form and conditions of the heat treatment jig 10, such as a container shape such as a sagger or crucible, or a plate shape such as a shelf board or setter.

[0024] The substrate 20 has a thermal spraying target area 22. The thermal spraying target area 22 is an area of ​​the substrate 20 onto which the thermal spray material constituting the thermal sprayed portion 30 is sprayed. The thermal spraying target area 22 can be, for example, all or part of the surfaces constituting the substrate 20, or a part of the surfaces constituting the substrate 20. The thermal spraying target area 22 should preferably include at least an area where an object to be heat treated is disposed.

[0025] The thermal spray target area 22 preferably has a surface shape that satisfies both the following (Condition 1) and (Condition 2). (Condition 1) The sum of the level difference Rk of the core portion and the height Rpk of the protruding peak portion is greater than 15 μm. (Condition 2) The protruding peak height Rpk is greater than 4.5 μm.

[0026] Here, the above-mentioned parameters such as the core level difference Rk and the peak height Rpk are parameters based on a load curve used to grasp the surface texture (see Figure 2). These parameters are load curve parameters based on a three-layer structure surface model specified in JIS B 0671-2 of the Japanese Industrial Standards (JIS).

[0027] Here, the load curve is a curve that expresses the ratio of the solid portion of the surface unevenness to the void portion in the height direction. Figure 2 is an explanatory diagram that schematically shows the relationship between the surface unevenness and the load curve. The load curve in Figure 2(b) shows the ratio of the solid portion to the void portion when the profile curve (smoothed roughness curve) in Figure 2(a) is cut horizontally at a certain height. The load curve in Figure 2(b) is expressed as the percentage of the solid portion (load length ratio) on the horizontal axis and the height on the vertical axis. The load curve parameters for the three-layer surface model include multiple parameters: the protruding peak height Rpk, the core level difference Rk (core height), the protruding valley depth Rvk, and the core load length ratios Mr1 and Mr2.

[0028] In addition, in analysis using a three-layer surface model, the surface asperities are divided into three regions in the height direction, and their heights and amounts (proportions of the total) are analyzed. The three-layer structure model is an analytical model that assumes three regions: (a) a region considered relatively susceptible to wear (initial wear region), (b) a region considered to have the function of withstanding load (core region), and (c) a valley-shaped region. Additionally, parameters corresponding to each of these regions are provided: peak height Rpk, which is an index of the average height of the peaks above the core region of the load curve (roughness curve); core level difference Rk, which is an index of the difference between the upper and lower levels of the core region of the load curve; and valley depth Rvk, which is an index of the average depth of the valleys below the core region of the load curve. By deriving these parameters, the surface properties can be understood.

[0029] The thermal spray target area 22 should satisfy the conditions defined based on the above-mentioned parameters. In this embodiment, the above-mentioned (Condition 1) and (Condition 2) are defined based on the level difference Rk of the core portion and the height Rpk of the protruding peak portion among these parameters, and the thermal spray target area 22 is required to satisfy these conditions.

[0030] The thermal spray target area 22 can be formed by various methods so as to have a surface shape that satisfies the above-mentioned conditions. For example, the thermal spray target area 22 can be formed by one method selected from shot blasting, laser processing, chemical etching, etc., or by a combination of several methods.

[0031] When forming the thermal spraying target area 22 using a shot blasting method, shot consisting of spherical particles is projected at high speed onto the ceramic surface of the substrate 20 to abrade the surface of the substrate 20. Using the shot blasting method, the surface of the thermal spraying target area 22 can be roughly roughened uniformly. Furthermore, when using the shot blasting method, the roughness and depth of the resulting irregularities can be adjusted by changing the shot material, particle size, and projection speed. Laser processing also uses a high-energy laser beam to form fine irregularities on the surface of the ceramic substrate 20. Laser processing allows for precise surface processing by adjusting the laser wavelength, irradiation time, focal length, etc., and can create the surface shape of the thermal spraying target area 22 with complex patterns and fine textures. Furthermore, chemical etching is a method of creating irregularities by partially dissolving the ceramic surface using corrosive chemicals. When forming the thermal spraying target area 22 using a chemical etching method, the intended irregularity pattern can be formed by applying chemicals to specific areas excluding the areas where the protective layer is applied.

[0032] The spray target region 22 may be formed by a mold embossing method (hereinafter also referred to as the "ME method") using a mold having a concave-convex shape corresponding to the surface shape that satisfies the above-mentioned conditions, instead of or in addition to one of the various methods described above, or some or all of the methods. Specifically, as will be described in detail in the description of the manufacturing method of the heat treatment jig 10 below, when forming the base member 20, the raw material of the base member 20 is pressed in a mold to form a green compact, and the green compact is then fired to form the spray target region 22. In this way, the green compact is fired in a state in which the fine pattern or texture engraved in the mold is transferred to the region on the surface of the material that will become the spray target region 22. As a result, the spray target region 22 can be prepared with a surface shape that satisfies the above-mentioned conditions more reliably and accurately than when using methods such as the shot blasting method, laser processing method, and chemical etching method described above.

[0033] The thermal spray portion 30 is a layer formed of a thermal spray material. The thermal spray portion 30 is formed by thermally spraying the thermal spray material onto the thermal spray target region 22 of the substrate portion 20. The thermal spray material may be selected from, for example, metals, metal alloys, ceramics, composite ceramics, or cermets to improve heat resistance, wear resistance, and reactivity with the heat-treated object. Suitable metals include tungsten, molybdenum, niobium, titanium, and tantalum, which have high thermal stability and wear resistance. When using ceramics as the thermal spray material, suitable materials include alumina, yttria-stabilized zirconia (YSZ), and zirconia, which exhibit stable properties even at high temperatures. These ceramic materials have excellent oxidation resistance and thermal shock resistance, making them suitable for use in harsh environments. Furthermore, composite ceramic materials may be made of a combination of ceramic and metal to improve wear resistance and thermal stability.

[0034] Furthermore, plasma spraying is preferably used as a method for spraying the spray material. Plasma spraying is a method for forming a coating layer by using high-temperature plasma to melt the spray material and spraying it toward a substrate at high speed. This method is effective for producing a high-density, uniform coating layer. The spray material may be sprayed onto the spray target area 22 using other methods in addition to or instead of the plasma spraying method. Other methods for spraying the spray material include, for example, high-velocity oxygen flame spraying (HVOF), arc spraying, or cold spraying. These methods may be selected appropriately depending on the properties and purpose of the spray material.

[0035] The thermal sprayed portion 30 is thermally sprayed with a peel strength of at least a predetermined value on the thermal spray target area 22. The heat treatment jig 10 sprays the thermal spray material onto the thermal spray target area 22 that satisfies the above (Condition 1) and (Condition 2), thereby achieving a peel strength of 3.5 [N / mm 2 ] or more.

[0036] <Method for manufacturing heat treatment jig 10> Next, we will explain a method for manufacturing the above-mentioned heat treatment jig 10. The heat treatment jig 10 can be manufactured through steps that roughly include a substrate preparation step and a thermal spraying step.

[0037] The substrate preparation step is a step of preparing the substrate 20. The substrate preparation step can be performed through steps further including a composition preparation step, a molding step, a firing step, and a spray target area formation step. Here, the composition preparation step is a step of preparing a composition that will be the raw material for the substrate 20. The molding step is a step of molding the composition to form a molded product, and the firing step is a step of firing the molded product. The spray target area formation step is a step for forming the spray target area 22 on the substrate 20.

[0038] In the composition preparation step, as described above, inorganic compounds such as oxides, carbides, nitrides, and borides may be prepared as the composition that forms the substrate portion 20. Specifically, in the composition preparation step, a composition containing one or more of silicon carbide, boron carbide, silicon nitride, boron nitride, aluminum nitride, alumina, yttria, zirconia, magnesia, mullite, and the like is prepared.

[0039] The molding step is a step of molding the composition prepared in the composition preparation step into a predetermined shape. In the molding step, the composition is formed into an appropriate shape depending on the usage form and usage conditions of the heat treatment jig 10. Specifically, in the molding step, the composition constituting the substrate portion 20 is formed into a container-like shape such as a sagger or crucible, or a plate-like shape such as a shelf or setter. The molding step is performed by a molding method such as press molding, slip casting, or CIP molding.

[0040] The firing step is a step of firing the composition formed into a predetermined shape in the above-mentioned forming step. The firing conditions in the firing step, such as the firing temperature and firing time, can be set appropriately depending on the type and blending amount of the composition constituting the substrate 20. For example, when the substrate 20 is made of mullite ceramics, the firing is performed at a maximum temperature of 1400°C to 1800°C, preferably 1500°C to 1650°C, for a predetermined time (for example, maintaining the maximum temperature for 6 hours or more). The firing treatment in the firing step can be performed in an appropriate atmosphere, but is preferably performed in an air atmosphere.

[0041] As described above, the spray target region forming step is a step for forming the spray target region 22 on the substrate 20. Here, the spray target region forming step can be performed after the firing step described above or during the molding step described above, depending on the method for forming the spray target region 22. Specifically, when the method for forming the spray target region 22 is a method for processing a fired product, such as the above-mentioned shot blasting method, laser processing method, or chemical etching method, the spray target region forming step is performed after the firing step. On the other hand, when the method for forming the spray target region 22 is a method for processing a composition during molding, such as the above-mentioned ME method, the spray target region forming step is performed during the molding step.

[0042] Specifically, when forming the sprayed region 22 by the ME method, a mold used to mold the composition has a surface defining a molding cavity into which the composition is introduced, and the surface (hereinafter also referred to as the "sprayed region forming portion 120") where the sprayed region 22 is to be formed has an uneven shape corresponding to the surface shape of the sprayed region 22. Various methods can be considered for forming the unevenness in the sprayed region forming portion 120 of the molding mold, such as chemical etching, laser engraving, and CNC machining, but it is preferable to form it by electrical discharge machining. Electrical discharge machining is a processing technique in which an electrode made of a conductive material such as a copper electrode is brought close to a molding mold made of a material such as carbon steel or alloy steel (SKD material, etc.), and a voltage is applied between the electrode and the molding mold to generate an electrical discharge in the small gap between the electrode and the molding mold.

[0043] A molding die 100 used when forming the thermal spray target region 22 by the ME method may be, for example, as shown in FIG. 3. Specifically, the molding die 100 has a main die 102, a lower die 104, and an upper die 106. The main die 102 has a cavity 110 that forms a cavity 108 (see FIG. 3(b)). The cavity 110 is formed so as to penetrate the main die 102. The lower die 104 is a first split die that is fitted into the cavity 110 from one side in the penetration direction (the lower side in the illustrated example). The upper die 106 is a second split die that is fitted into the cavity 110 from the other side in the penetration direction (the upper side in the illustrated example).

[0044] The cavity 108 is a space into which a composition for forming the substrate portion 20 is introduced. The cavity 108 is formed between the lower mold 104 and the upper mold 106 when the lower mold 104 and the upper mold 106 are fitted into the hollow 110 of the main mold 102. The cavity 108 is defined by a first partition surface 112 consisting of the top surface of the lower mold 104, a second partition surface 114 consisting of the bottom surface of the upper mold 106, and a third partition surface 116 consisting of the inner peripheral surface of the hollow 110. When the thermal spraying target region 22 is formed by the ME method, some or all of these partition surfaces are used as the thermal spraying target region forming portion 120. In the illustrated example, the entire area of ​​the first partition surface 112 is used as the thermal spraying target region forming portion 120. When the thermal spraying target region 22 is formed by the ME method, a molding die 100 is prepared in which a concave-convex shape corresponding to the surface shape of the thermal spraying target region 22 is formed on the partition surface forming the cavity 108 by a method such as the above-mentioned electric discharge machining. Therefore, when forming the thermal spray target region 22 by the ME method, a green compact having an uneven shape formed in the portion that will become the thermal spray target region 22 is formed by loading a raw material composition for the substrate portion 20 into the cavity 108 of the molding die 100 prepared as described above and pressing it. Therefore, when forming the thermal spray target region 22 by the ME method, a green compact having an uneven shape formed in the portion that will become the thermal spray target region 22 can be formed by firing the green compact prepared in this manner in a firing step.

[0045] The substrate preparation process is completed through the steps including the composition preparation process, molding process, firing process, and thermal spraying target area formation process as described above. This prepares the substrate 20 having the thermal spraying target area 22. Once preparation of the substrate 20 is complete, the thermal spraying process is carried out.

[0046] The thermal spraying process is a process of forming the thermal sprayed portion 30 by thermally spraying a thermal spray material onto the thermal spray target region 22 of the substrate 20 prepared in the substrate preparation process described above. As described above, the thermal spraying of the thermal spray material can be carried out by using one or more thermal spraying methods, such as plasma spraying, high velocity oxygen flame spraying (HVOF), arc spraying, or cold spraying. When the purpose is to form a high-density and uniform coating layer on the thermal spray target region 22 using the thermal sprayed portion 30, the plasma spraying method can be suitably used.

[0047] <Action and effect> The heat treatment jig 10 and the method for manufacturing the heat treatment jig 10 according to the above embodiment have the following characteristic configurations (A) to (F), which provide unique effects.

[0048] (A) The heat treatment jig 10 of this embodiment has a substrate portion 20 made of ceramic and a sprayed portion 30 formed from a spray material, the substrate portion 20 has a spray target area 22 onto which the spray material is sprayed, the spray target area 22 has a surface shape in which the sum of the level difference Rk of the core portion and the protruding peak height Rpk is greater than 15 [μm] and the protruding peak height Rpk is greater than 4.5 [μm], and the sprayed portion 30 is formed by spraying the spray material onto the spray target area 22 of the substrate portion 20.

[0049] In the heat treatment jig 10 of this embodiment, an area that satisfies both (Condition 1) and (Condition 2) described above is treated as the spray target area 22, and the sprayed material is sprayed to form the sprayed portion 30. Therefore, by configuring the heat treatment jig 10 according to the above (A), it is possible to provide a heat treatment jig 10 in which the sprayed material sprayed on the substrate portion 20 is less likely to peel off.

[0050] (B) The heat treatment jig 10 of this embodiment has a thermal sprayed portion 30 with a resistance of 3.5 [N / mm 2 ] or more peel strength.

[0051] The heat treatment jig 10 has a peel strength of 3.5 [N / mm] after heat treatment at 1350°C as described above (B). 2 ] or more, the thermal spray material sprayed onto the substrate 20 is unlikely to peel off.

[0052] (C) The heat treatment jig 10 of this embodiment is formed by pressing the raw material of the substrate portion 20 using a mold having an uneven shape corresponding to the surface shape of the thermal spray target area 22, and then firing the resulting green compact.

[0053] By satisfying the condition (C) above, the heat treatment jig 10 can reliably and accurately prepare the substrate portion 20 having the above-described surface shape in the thermal spraying target region 22. Therefore, by configuring the heat treatment jig 10 according to the above (C), it is possible to more reliably make the thermal spray material sprayed onto the substrate less likely to peel off.

[0054] (D) In ​​the heat treatment jig 10 of this embodiment, the substrate portion 20 is formed from mullite ceramics, which is a fired product produced by firing a composition containing alumina and silica as main components.

[0055] By adopting the configuration according to (D) above, the heat treatment jig 10 can be provided as one made of mullite ceramics that has strength in high-temperature environments, while the sprayed material is not easily peeled off.

[0056] (E) The manufacturing method of the heat treatment jig 10 exemplified in this embodiment includes a substrate preparation step of preparing a substrate 20 made of ceramic and having a spray target area 22 with a surface shape in which the sum of the level difference Rk of the core portion and the protruding peak height Rpk is greater than 15 [μm] and the protruding peak height Rpk is greater than 4.5 [μm], and a thermal spraying step of spraying a thermal spray material onto the spray target area 22 of the substrate 20 prepared in the substrate preparation step.

[0057] The manufacturing method for the heat treatment jig 10 involves preparing a substrate 20 that satisfies the above-mentioned (Condition 1) and (Condition 2), and then spraying a thermal spray material onto the substrate 20 in a thermal spraying process. Therefore, according to the manufacturing method for the heat treatment jig 10, it is possible to manufacture a heat treatment jig 10 in which the thermal spray material sprayed onto the substrate 20 is less likely to peel off.

[0058] (F) In the manufacturing method of the heat treatment jig 10 of this embodiment, in the substrate preparation process, the raw material of the substrate 20 is pressed using a mold having a concave-convex shape corresponding to the surface shape, and the green compact formed is then fired to prepare a substrate 20 having a thermal spray target area 22 having the surface shape.

[0059] By satisfying the condition (F) above, the manufacturing method for the heat treatment jig 10 can reliably and accurately prepare the substrate portion 20 whose thermal spray target region 22 has the above-described surface shape. Therefore, by adopting the configuration according to (F) above, the manufacturing method for the heat treatment jig 10 can more reliably manufacture a substrate in which the thermal spray material sprayed on the substrate is less likely to peel off, with a high yield. <<About Modifications>> The heat treatment jig 10 described above merely illustrates one embodiment of the present invention, and the configuration can be appropriately changed, omitted, or added without departing from the spirit of the present invention. For example, it is not necessary to satisfy all of the above (A) to (F), and it is possible to have some of the configurations missing, or some of the configurations changed to other configurations. [Example]

[0060] Examples of heat treatment jigs and manufacturing methods thereof are described below. In these examples, eight types of samples, Samples a to h, were prepared as shown in Table 1. Samples a to h were prepared as ceramic substrates 20 by preparing a mixed powder containing alumina and silica (silica) as the main components, compacting the powder, and firing it at 1600°C. Specifically, in this example, a mixed powder containing 68% alumina and 32% silica by weight was prepared. This mixed powder was mixed with water, a binder, and other ingredients to form a slurry. Granules formed using a spray dryer were then pressed into a compact and fired at 1600°C to form mullite ceramics, which were then used as the substrates 20. The substrates 20 constituting Samples a to h contained a mullite phase ratio of 70% to 80% by weight. The ratio of the mullite phase contained in the mullite ceramics was calculated using Rietveld analysis. The measurements were performed using a RINT-Ultima3 X-ray diffractometer (goniometer radius 285 mm) manufactured by Rigaku Corporation. The X-ray tube used in the X-ray diffractometer was a Cu tube operated at 40 kV and 40 mA, combined with a Ni filter to remove Kβ. The detector used a high-speed one-dimensional detector, the D / teX Ultra2. The measurement optical system used a focusing optical system, with a divergence slit of 1 / 2°, a scattering slit of 8 mm, a receiving slit of 13 mm, and a Soller slit with an opening angle of 5°. The analysis software used was PDXL2 equipped with a Rietveld analysis program.

[0061] Sample a is a sample in which the base material portion was formed by a conventionally known method without carrying out the above-mentioned spray target area formation process, and then the surface was sprayed using a plasma spraying method in the same manner as described in the above-mentioned spraying process.

[0062] For each of Samples b to h, a portion corresponding to the substrate 20 was formed in the same manner as in the substrate preparation step described in the above embodiment, and a thermal spray material was sprayed onto the region corresponding to the thermal spraying target region 22 in the same manner as in the thermal spraying step described above. Among Samples b to h, Samples b to g were samples for which the thermal spraying target region forming step was performed by shot blasting. As shown in Table 1, Samples b to g were samples formed by varying the number of shot blasts performed on the portion corresponding to the substrate 20. For Samples b to f, shot blasting was performed using silicon carbide (SiC) shot with abrasive grains having a particle size of #48. For Sample g, shot blasting was performed using silicon carbide (SiC) shot with abrasive grains having a particle size of #24. For Samples b to g, shot blasting was performed the number of times shown in Table 1, where one shot was impacted from a distance of 100 mm from the region corresponding to the thermal spraying target region 22 and moved at a speed of 10 mm / sec for 5 seconds. Sample h is a sample in which the step of forming a region to be sprayed was carried out by the ME method.

[0063] [Table 1]

[0064] In preparing the above-mentioned samples a to h, yttria-stabilized zirconia (YSZ) was used as the thermal spray material, and the thermal spraying process was carried out by plasma spraying with a target film thickness of 150 μm. Samples a to h were prepared by heat treatment in an oxidizing atmosphere at 1350°C after the thermal spraying process.

[0065] For the thermal spray target area 22 of the above-mentioned samples a to h, the load curve parameters and arithmetic mean roughness were derived using a three-layer structure surface model specified in JIS B 0671-2 of the Japanese Industrial Standards (JIS). In addition, for samples a to h, a peeling test was conducted on the thermal sprayed portion 30 formed by thermal spraying on the thermal spray target area 22.

[0066] Specifically, for the peel test, as shown in FIG. 4(a), two plates 130, 132 were prepared for Samples a to h, each cut to a size of 40 mm × 15 mm. Then, as shown in FIG. 4(b), epoxy resin was applied to the central portions 130a, 132a of each plate 130, 132, and the two plates 130, 132 were attached and fixed so that the spray target regions 22 faced each other and crossed each other to prepare a test piece 140. The cross-shaped test piece 140 thus formed was set in a three-point bending tester as shown in FIG. 5. Specifically, the upper plate 130 was set on a pair of lower bending jigs 150, 150 spaced apart from each other in the three-point bending tester. Then, as shown in FIG. 6, a measuring jig 152 was placed on the lower plate 132, and a load was applied to the plate 132 via the measuring jig 152.

[0067] Here, the measuring jig 152 is a member including a pressure receiving portion 154, a first pressing portion 156, and a second pressing portion 158. The pressure receiving portion 154, the first pressing portion 156, and the second pressing portion 158 are each formed in a rectangular shape. The first pressing portion 156 and the second pressing portion 158 have approximately the same length. The measuring jig 152 is formed so that the first pressing portion 156 and the second pressing portion 158 protrude in the same direction at one end side and the other end side of the pressure receiving portion 154. As a result, the measuring jig 152 is formed in a U-shape.

[0068] The measuring jig 152 is set on the plate-like body 132 located below the plate-like body 130, while the plate-like body 130 of the test piece 140 is placed across the lower bending jigs 150, 150. The measuring jig 152 is positioned so that the pressure-receiving portion 154 is approximately parallel to the plate-like body 132, the first pressing portion 156 abuts against one side of the plate-like body 132, with the central portion 132a as the boundary, and the second pressing portion 158 abuts against the other side of the central portion 132a as the boundary. In this state, the upper bending jig 160 of the three-point bending tester is abutted against the pressure-receiving portion 154 from above, and a load is applied to the pressure-receiving portion 154 from the upper bending jig 160. When a load is applied in this manner, the thermal sprayed portion 30 applied to at least one of the plate-like bodies 130, 132 eventually peels off. In this example, the load at this time was divided by the area of ​​the peeled portion to calculate the peel strength. Based on the peel strength calculated in this way, the peel characteristics were evaluated. In this example, the peel strength was 3.5 [N / mm 2 ] or more is marked "○", 3.5 [N / mm 2 If the value was less than 1, it was judged as "×".

[0069] The relationship between the peel strength and peel characteristics calculated as described above, the load curve parameters, and the arithmetic mean roughness is shown in Table 1. As can be seen from Table 1, among samples a to h, the peel strength was 3.5 [N / mm 2 When these samples a to h were examined from the viewpoint of the relationship between the load curve parameters, the arithmetic mean roughness, and the peel strength (peel characteristics), it was found that if the condition in the above embodiment, defined as (Condition 1), that the sum (Rk+Rpk) of the core level difference Rk (core height) and the protruding peak height Rpk is 15 [μm] or more, and the condition, defined as (Condition 2), that the protruding peak height Rpk is greater than 4.5 [μm], is satisfied, the peel strength would be 3.5 [N / mm 2 ] or more.

[0070] Based on the above test results, it was found that if Rk+Rpk is less than 15 μm, the surface area of ​​the sprayed portion 30 cannot be sufficiently secured, and peeling may be more likely to occur. In contrast, it was found that if Rk+Rpk is 15 μm or more, as in the above (Condition 1), the surface area of ​​the sprayed portion 30 can be sufficiently secured, and peeling tends to be less likely to occur. Furthermore, based on the above test results, it was found that it is desirable for Rk+Rpk to be 50 μm or less. This is presumably because if Rk+Rpk exceeds 50 μm, the difference in film thickness in the sprayed portion 30 becomes large, making cracks more likely to occur due to the non-uniformity of the film thickness.

[0071] Furthermore, it is assumed that the coating layer formed by the sprayed portion 30 will be slightly recessed between two adjacent protruding peaks in the sprayed region 22, making it less likely to peel off. However, if the protruding peak height Rpk is 4.5 μm or less, the difference in height between the peaks provided in the core portion and the protruding peaks is small, making it difficult for the coating layer formed by the sprayed portion 30 to have the recessed shape described above, and resulting in insufficient peel strength. Therefore, if the protruding peak height Rpk is greater than 4.5 μm as in the above (Condition 2), it is assumed that the coating layer formed by the sprayed portion 30 will be slightly recessed between adjacent protruding peaks, making it less likely to peel off.

[0072] Furthermore, based on the above test results, it was found that the protruding peak height Rpk is preferably 10 μm or less. This is presumably because if the protruding peak height Rpk exceeds 10 μm, very steep peaks are formed, which may be easily damaged during thermal spraying of the thermal spray material, resulting in defects.

[0073] The present invention is not limited to the configurations described in the above-described embodiments, etc., and appropriate design modifications, etc. are possible within the scope of the technical concept of the present invention. The components of the above-described embodiments and variations may be arbitrarily selected and combined. Furthermore, any component of each embodiment or variation may be arbitrarily combined with any component described in the means for solving the problems, the detailed description, etc., or any component embodying any component described in the means for solving the problems, the detailed description, etc. The present invention also intends to obtain rights to these in the present application or in divisional applications, modified applications, etc. based on the present application. [Industrial Applicability]

[0074] The heat treatment jig and the method for manufacturing the heat treatment jig of the present invention can be suitably used in all types of heat treatment jigs, such as setters, shelves, saggers, crucibles, and the like. [Explanation of symbols]

[0075] 10: Heat treatment jig 20: Base material part 22: Thermal spray target area 30: Thermal sprayed part Mr1: Load length ratio Mr2: Load length ratio Rk: Level difference Rpk: Height of protruding peak

Claims

1. a ceramic substrate; a sprayed portion formed by a spray material; and the substrate portion has a thermal spray target area onto which the thermal spray material is sprayed, The thermal spray target area has a surface shape in which the sum of the level difference Rk of the core portion and the protruding peak height Rpk is greater than 15 [μm] and the protruding peak height Rpk is greater than 4.5 [μm], The thermal treatment jig is characterized in that the thermal sprayed portion is formed by thermally spraying a thermal spray material onto the thermal spray target area of ​​the base material.

2. 2. The heat treatment jig according to claim 1, wherein the thermal spray target area is formed by pressing the raw material of the base material using a mold having an uneven shape corresponding to the surface shape, and then firing the compact.

3. 3. The heat treatment jig according to claim 1, wherein the base material is formed from mullite ceramics, which is the fired product produced by firing a composition containing alumina and silica as main components.

4. a substrate preparation step of preparing a substrate made of ceramics and having a thermal spray target region having a surface shape in which the sum of the level difference Rk of the core portion and the protruding peak height Rpk is greater than 15 [μm] and the protruding peak height Rpk is greater than 4.5 [μm]; a thermal spraying step of thermally spraying a thermal spray material onto the thermal spray target region of the substrate prepared in the substrate preparation step; A method for manufacturing a heat treatment jig, comprising:

5. 5. The method for manufacturing a heat treatment jig according to claim 4, wherein in the substrate portion preparation step, a raw material for the substrate portion is pressed using a mold having a concave-convex shape corresponding to the surface shape, and the molded compact is then fired to prepare the substrate portion having the thermal spray target region having the surface shape.

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