JP2010242225A - Ceramic-coated member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ceramic-coated member in which a gradient composition structure, in which the composition of the boundary between the respective films continuously changes, is formed using electron beam physical deposition, and which has excellent heat shielding properties and excellent thermal cycle life. <P>SOLUTION: The ceramic-coated member is composed in such a way that at least a thermal stress relaxing layer 22 and a heat shielding layer 23 are stacked in this order on a base material 20 comprising metals or ceramics. Further, in the boundary 24 between the thermal stress relaxing layer 22 and the heat shielding layer 23 and in the vicinity thereof, the concentration of zirconium oxide forming the layer 22 is continuously reduced from the layer 22 toward the layer 23, and at the same time, the concentration of hafnium oxide forming the layer 23 is continuously increased. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a coating member coated with a metal or ceramic material using electron beam physical vapor deposition, and in particular, heat resistance, oxidation resistance, heat resistance of a member exposed to high temperature in an industrial gas turbine or jet engine. The present invention relates to a ceramic-coated member that is improved in cycle performance and the like.

  High-temperature members such as moving blades (blades), stationary blades (vanes), and combustors in industrial gas turbines and jet engines are exposed to combustion gases exceeding 1000 ° C. In general, these high-temperature members are made of a heat-resistant alloy called a nickel-base superalloy. However, when the temperature exceeds 1000 ° C., the strength rapidly decreases. Therefore, these high temperature members are controlled to a temperature of 950 ° C. or lower by cooling the front and back surfaces with a cooling medium such as air or steam. However, increasing the combustion gas temperature can improve combustion efficiency and power generation efficiency, so the combustion gas temperature of industrial gas turbines and jet engines in recent years has increased to 1300 ° C, and further to 1500 ° C. I'm following a course. Therefore, in the conventional cooling method, it is difficult to control the temperature of the high temperature member to 900 ° C. or less.

  Here, FIG. 8 shows a part of a cross-sectional structure of a moving blade 200 used in the latest industrial gas turbine and jet engine. FIG. 9 is a schematic diagram for showing the effect of the thermal barrier coating.

  As shown in FIG. 8, in the moving blade 200, the surface of a heat-resistant metal member 210 is coated with a metal layer 220 having excellent oxidation resistance, and the surface of the metal layer 220 has a low thermal conductivity, resulting in a heat shielding property. An excellent ceramic layer 230 is coated. Here, the metal layer 220 and the ceramic layer 230 function as the thermal barrier coating layer 240. The surface of the ceramic layer 230 is in contact with the combustion gas, and the surface of the refractory metal member 210 opposite to the thermal barrier coating layer 240 is in contact with the cooling medium.

In this moving blade 200, as shown in FIG. 9, the ceramic layer 230 has a large temperature gradient to suppress the temperature rise of the metal base material due to the high temperature of the combustion gas. In FIG. 9, the horizontal axis indicates the distance from the surface in contact with the combustion gas of the moving blade 200 shown in FIG. 8 toward the refractory metal member 210. The vertical axis indicates the temperature of the moving blade 200. As the ceramic material used for the ceramic layer 230, a material having a low thermal conductivity and excellent heat resistance is preferable. Generally, zirconium oxide stabilized with yttrium oxide (Y ₂ O ₃ ). (ZrO ₂ ) is widely used. The thermal conductivity of the yttrium oxide-stabilized zirconium oxide is about 2 W / (m · K), which is about 1/10 to 1/100 of the thermal conductivity of the metal material. The thermal conductivity of this yttrium oxide-stabilized zirconium oxide is a material with low thermal conductivity among ceramic materials, but by introducing a large number of pores in the coating by using plasma spraying during thermal barrier coating, The thermal conductivity can be lowered to about 1.4 W / (m · K).

  However, the surface of such a thermal barrier coating layer 240 is required to have excellent wear resistance and erosion resistance because solid particles such as oxide scale collide at high speed. On the other hand, on the surface of the metal layer 220, an oxide layer that causes peeling of the ceramic layer 230 grows, so that excellent oxidation resistance is also required. Furthermore, since the moving blade 200 is exposed to a high temperature for a long time, a thermal stress due to a difference in thermal expansion between the metal layer 220 and the ceramic layer 230 is repeatedly generated with the start / stop. Therefore, since peeling of the ceramic layer 230 is accelerated, thermal stress relaxation is also required.

  As described above, since various characteristics are required in the thermal barrier coating applied to the high temperature member such as the moving blade 200, the above-described requirements can be satisfied by a combination of a simple metal layer and a ceramic layer. Have difficulty. In view of this, it has been attempted to satisfy the above-described requirements by making the thermal barrier coating layer multi-layered to share the function of each layer.

  For example, a metal part having a multilayer structure such as a barrier layer, a hot gas corrosion prevention layer, a protective layer, a thermal barrier layer, and a smooth layer is disclosed (for example, see Patent Document 1). Further, a gas turbine member having a two-layer structure of a ceramic layer having a ceramic layer having high strength and high toughness and a ceramic layer having high temperature stability is disclosed (for example, see Patent Document 2). Furthermore, a ceramic component for a gas turbine including an adhesion promoting layer, a stress relaxation layer, a crack progress preventing layer, a surface corrosion resistant layer, and the like is disclosed (for example, see Patent Document 3).

  Moreover, although the film in the above-described conventional high-temperature parts is formed by thermal spraying, metal parts having a thermal barrier coating film formed using electron beam physical vapor deposition are also disclosed (for example, patent documents). 4). In this electron beam physical vapor deposition, the evaporated coating material grows on the substrate to form a film, so that a columnar ceramic structure is obtained, which is superior in thermal stress relaxation compared to thermal spraying.

  Here, FIG. 10 shows a diagram for explaining the outline of electron beam physical vapor deposition. Further, FIG. 11A shows the film thickness direction in the vicinity of the interface between the ceramic material A layer and the ceramic material B layer when a gradient composition layer is formed for two types of ceramic materials (A, B) using thermal spraying. A change in characteristic X-ray intensity (corresponding to the concentration of ceramic material A) is schematically shown. FIG. 11B shows a film in the vicinity of the interface between the ceramic material A layer and the ceramic material B layer when the gradient composition layer is formed for two types of ceramic materials (A, B) using electron beam physical vapor deposition. A change in characteristic X-ray intensity in the thickness direction (corresponding to the concentration of the ceramic material A) is schematically shown.

  In the electron beam physical vapor deposition shown in FIG. 10, evaporation targets 250 a and 250 b which are two types of ingots are prepared, and the gradient composition layer is formed by controlling the evaporation amount of the vapor 270 by gradually changing the output of the electron beam 260. Let it form. In the gradient composition layer formed by this electron beam physical vapor deposition, the characteristic X-ray intensity in the film thickness direction in the vicinity of the interface between the ceramic material A layer and the ceramic material B layer is as shown in FIG. Distribution. On the other hand, in the gradient composition layer formed by thermal spraying, the characteristic X-ray intensity in the film thickness direction in the vicinity of the interface between the ceramic material A layer and the ceramic material B layer has a stepwise intensity distribution as shown in FIG. 11A. .

JP 2003-41358 A JP 2001-348655 A JP 2006-124226 A JP 2005-313644 A

  In the multilayer coating described above, it is important to relieve thermal stress caused by adhesion between each coating, crystal structure consistency, and thermal expansion difference. Ideally, the gradient composition should change.

  In thermal spraying, which is a conventional thermal barrier coating method, a gradient composition is achieved by changing the blending ratio of powder to be sprayed stepwise, and it is necessary to replace the thermal spray powder every time the composition is changed. Therefore, as described above, the characteristic X-ray intensity in the thickness direction in the vicinity of the interface between the ceramic material A layer and the ceramic material B layer in the gradient composition layer has a stepwise intensity distribution, and the composition is continuously changed. I couldn't.

  Further, in the conventional electron beam physical vapor deposition, the evaporation vapor amount of the evaporation target with respect to the electron beam output is not necessarily constant, and a time lag occurs in the evaporation of both evaporation targets. Therefore, as described above, the characteristic X-ray intensity in the film thickness direction in the vicinity of the interface between the ceramic material A layer and the ceramic material B layer in the gradient composition layer has a severe intensity distribution, and the composition can be continuously changed. could not.

  Therefore, the present invention has been made to solve the above-mentioned problems, and an electron beam physical vapor deposition is used to form a gradient composition structure in which the composition of the interface between the films changes continuously, thereby providing a heat shielding property. An object of the present invention is to provide a ceramic-coated member having an excellent thermal cycle life.

  In order to achieve the above object, according to one aspect of the present invention, it is configured by laminating at least a thermal stress relaxation layer and a thermal barrier layer in this order on a base material made of metal or ceramics by electron beam physical vapor deposition. 1st ceramic material which is a ceramic coating | coated member and forms the said thermal stress relaxation layer toward the said thermal insulation layer from the said thermal stress relaxation layer in the boundary layer of the said thermal stress relaxation layer and the said thermal insulation layer There is provided a ceramic-coated member characterized in that the concentration of the second ceramic material forming the heat-shielding layer is continuously increased while the concentration of is continuously reduced.

  According to this ceramic covering member, the concentration of the first ceramic material forming the thermal stress relaxation layer is continuous between the thermal stress relaxation layer and the thermal barrier layer from the thermal stress relaxation layer to the thermal barrier layer. And the gradient composition layer in which the concentration of the second ceramic material forming the heat shield layer continuously increases. As a result, the concentration of thermal stress at the contact portion of the coating of the different material can be relaxed, and the thermal cycle characteristics can be improved.

  According to another aspect of the present invention, there is provided a ceramic coating formed by laminating at least an oxygen barrier layer, a thermal stress relaxation layer, and a thermal barrier layer in this order on a substrate made of metal or ceramic by electron beam physical vapor deposition. A concentration of a third ceramic material that forms the oxygen barrier layer from the oxygen barrier layer toward the thermal stress relaxation layer in a boundary layer between the oxygen barrier layer and the thermal stress relaxation layer; The thermal stress relaxation is continuously reduced and the concentration of the first ceramic material forming the thermal stress relaxation layer is continuously increased, and the thermal stress relaxation is performed in a boundary layer between the thermal stress relaxation layer and the thermal barrier layer. The concentration of the first ceramic material that forms the thermal stress relaxation layer decreases continuously from the layer toward the thermal barrier layer, and the second ceramic that forms the thermal barrier layer Ceramic coating member is provided, wherein the concentration of the charge increases continuously.

  According to this ceramic covering member, the concentration of the third ceramic material forming the oxygen barrier layer is continuously between the oxygen barrier layer and the thermal stress relaxation layer from the oxygen barrier layer toward the thermal stress relaxation layer. A gradient composition layer in which the concentration of the first ceramic material forming the thermal stress relaxation layer increases continuously while decreasing. Furthermore, between the thermal stress relaxation layer and the thermal barrier layer, the concentration of the first ceramic material forming the thermal stress relaxation layer continuously decreases from the thermal stress relaxation layer to the thermal barrier layer, and the thermal barrier layer is also shielded. A gradient composition layer in which the concentration of the second ceramic material forming the thermal layer continuously increases is obtained. As a result, the concentration of thermal stress at the contact portion of the coating of the different material can be relaxed, and the thermal cycle characteristics can be improved.

  According to the present invention, a gradient coated structure in which the composition of the interface between each film continuously changes is formed using electron beam physical vapor deposition, and a ceramic-coated member having excellent heat shielding characteristics and thermal cycle life is provided. be able to.

It is the figure which showed the cross section of the ceramic coating | coated member of 1st Embodiment. It is sectional drawing which shows the outline | summary of the electron beam physical vapor deposition for manufacturing a ceramic coating | coated member. It is the figure which showed the cross section of the ceramic coating | coated member of 2nd Embodiment. It is sectional drawing which shows the outline | summary of the electron beam physical vapor deposition for manufacturing a ceramic coating | coated member. 6 is a diagram showing a backscattered electron image obtained by observing a cross section of a test piece 3 with an SEM in Example 3. FIG. It is a figure which shows the result of the elemental distribution measurement of the boundary part in the test piece 3 implemented in Example 3, and its vicinity. The figure which shows the relationship between the angle (theta) which the contact surface of a zirconium oxide ingot and a hafnium oxide ingot makes with respect to the center axis | shaft of a columnar laminated body, and the thickness of the gradient composition layer formed when using the ingot of the angle It is. It is a figure which shows a part of cross-sectional structure of the moving blade used for the latest industrial gas turbine and jet engine. It is a schematic diagram for showing the effect of thermal barrier coating. It is a figure for demonstrating the outline | summary of electron beam physical vapor deposition. Change in characteristic X-ray intensity in the film thickness direction in the vicinity of the interface between the ceramic material A layer and the ceramic material B layer when a gradient composition layer is formed for two types of ceramic materials (A, B) using a thermal spraying method FIG. Characteristic X-ray intensity in the film thickness direction in the vicinity of the interface between the ceramic material A layer and the ceramic material B layer when a gradient composition layer is formed on two types of ceramic materials (A, B) using electron beam physical vapor deposition It is a figure which shows typically the change of.

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

(First embodiment)
FIG. 1 is a view showing a cross section of the ceramic-coated member 10 of the first embodiment.

  As shown in FIG. 1, the ceramic covering member 10 includes a base material 20, an antioxidant layer 21 laminated on the base material 20, a thermal stress relaxation layer 22 laminated on the antioxidant layer 21, and this heat. And a heat shield layer 23 laminated on the stress relaxation layer 22.

  Further, in the boundary portion 24 between the thermal stress relaxation layer 22 and the thermal barrier layer 23 and in the vicinity thereof, the concentration of the ceramic material forming the thermal stress relaxation layer 22 from the thermal stress relaxation layer 22 toward the thermal barrier layer 23 is increased. While it decreases continuously, the density | concentration of the ceramic material which forms the thermal insulation layer 23 becomes a structure which increases continuously. The boundary portion 24 and the vicinity thereof function as a boundary layer.

  The base material 20 is made of, for example, a heat-resistant metal material such as a Ni-base superalloy or a ceramic material such as silicon nitride. Examples of the substrate 20 include members exposed to high-temperature gas in industrial gas turbines, jet engines, and the like, but are not limited thereto, and may be any high-temperature member that requires ceramic coating.

  The antioxidant layer 21 is a film that suppresses the formation of oxides on the surface of the base material 20 and improves the bondability with the thermal stress relaxation layer 22, and is a metal material having excellent corrosion resistance, oxidation resistance, and crack resistance. Composed. The antioxidant layer 21 is made of, for example, a Ni-based alloy, a Co-based alloy, a Ni—Co-based alloy, or the like to which Cr, Al, and Y are added at a predetermined ratio. Further, the antioxidant layer 21 is formed on the surface of the substrate 20 by plasma spraying or the like.

The thermal stress relaxation layer 22 is a film made of a ceramic material having a thermal expansion coefficient larger than that of the thermal barrier layer 23. As a ceramic material for forming this film, for example, a stabilized zirconium oxide ceramic material mainly composed of zirconium oxide (ZrO ₂ ) is used. Further, rare earth element oxides such as yttria (Y ₂ O ₃ ) and ceria (Ce ₂ O ₃ ) are added to zirconium oxide as a stabilizer.

The heat shield layer 23 is a film made of a ceramic material having excellent heat resistance and low thermal conductivity. As a ceramic material for forming this film, for example, a stabilized hafnium oxide ceramic material mainly composed of hafnium oxide (HfO ₂ ) is used. Moreover, oxides of rare earth elements such as yttria (Y ₂ O ₃ ) and ceria (Ce ₂ O ₃ ) are also added to hafnium oxide as a stabilizer.

  Further, at the boundary portion 24 between the thermal stress relaxation layer 22 and the thermal barrier layer 23 and in the vicinity thereof, the concentration of zirconium oxide forming the thermal stress relaxation layer 22 is continuous from the thermal stress relaxation layer 22 toward the thermal barrier layer 23. In addition, the concentration of hafnium oxide forming the heat shielding layer 23 increases continuously. That is, a gradient composition layer in which the concentrations of zirconium oxide and hafnium oxide continuously change in the thickness direction is formed in the boundary portion 24 between the thermal stress relaxation layer 22 and the heat shielding layer 23 and in the vicinity thereof. Here, considering the generation of thermal stress, for example, the thickness of the gradient composition layer is preferably about ¼ of the thickness of the ceramic layer composed of the thermal stress relaxation layer 22 and the thermal barrier layer 23. On the other hand, in consideration of the heat shielding characteristics, the thickness of the gradient composition layer is preferably about ½ of the thickness of the ceramic layer composed of the thermal stress relaxation layer 22 and the heat shielding layer 23. The thickness of the gradient composition layer is not limited to this, and is appropriately set according to the requirements of the base material 20.

  Next, the manufacturing method of the ceramic covering member 10 is demonstrated with reference to FIG.

  FIG. 2 is a cross-sectional view showing an outline of electron beam physical vapor deposition (EB-PVD) for manufacturing the ceramic-coated member 10.

  First, the antioxidant layer 21 made of the above metal material is formed on the surface of the substrate 20 by plasma spraying or the like.

  Subsequently, the thermal stress relaxation layer 22 and the thermal barrier layer 23 formed on the antioxidant layer 21 are formed by electron beam physical vapor deposition. Hereinafter, a method for forming the thermal stress relaxation layer 22 and the thermal barrier layer 23 will be specifically described.

  In this electron beam physical vapor deposition, an ingot 40 made of ceramics is irradiated with an electron beam 45 in a vacuum, and the surface of the oxidation layer 21 heated to a high temperature is melted by melting the ingot surface to form an evaporating vapor 46. Apply. At this time, as shown in FIG. 2, the base material 20 is rotated at a constant speed in a predetermined direction with the central axis of the base material 20 as a rotation axis so that the surface of the antioxidant layer 21 can be uniformly coated with ceramics. It has become. For example, when ceramic coating is performed by this method, the coating is generally performed to a thickness of 200 to 300 μm at a coating speed of about 100 μm / h (thickness coated in one hour). On the other hand, the rotation speed of the base material 20 is set to about 10 rpm (the number of rotations per minute). That is, the thickness coated per rotation is about 0.17 μm, and even when the substrate 20 is rotated and coated, a good gradient composition layer can be formed regardless of the location of the substrate 20. it can.

  The ingot 40 has a zirconium oxide ingot 41 and a hafnium oxide ingot 42 stacked in a columnar shape in a water-cooled crucible 50 such that the side that evaporates first becomes the zirconium oxide ingot 41. Further, the contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42 is configured to have a predetermined angle θ with respect to the central axis of the columnar laminate.

  Here, the predetermined angle θ is preferably 45 to 85 degrees. The predetermined angle θ is preferable when the angle is less than 45 degrees, the thickness of the gradient composition layer becomes thicker than necessary. That is, the thickness of the entire film is increased, the film formation time is long, and the film is easily peeled off. Moreover, when the thickness of the whole film | membrane is decided previously, the thickness of the required heat-shielding layer will become thin. On the other hand, when it exceeds 85 degrees, the effect of providing an angle on the contact surface is impaired, and a continuous gradient composition is not formed.

  As described above, by forming the contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42 with a predetermined angle θ with respect to the central axis of the columnar laminate, this portion becomes the evaporated vapor 46. In this case, the vaporized vapor 46 having a composition containing both components of zirconium oxide and hafnium oxide can be formed. The component composition of the evaporated vapor 46 when the portion of the ingot 40 having the predetermined angle θ evaporates is such that the concentration of zirconium oxide continuously decreases and the concentration of hafnium oxide continuously increases. As a result, the concentration of zirconium oxide forming the thermal stress relaxation layer 22 continuously decreases between the thermal stress relaxation layer 22 and the thermal barrier layer 23 from the thermal stress relaxation layer 22 toward the thermal barrier layer 23. At the same time, a gradient composition layer in which the concentration of hafnium oxide that forms the heat shielding layer 23 continuously increases is formed.

  Further, by adjusting the predetermined angle θ described above, the thickness of the gradient composition layer and the concentration gradient of zirconium oxide and hafnium oxide in the gradient composition layer can be adjusted. Furthermore, in this ingot 40, the thickness of the thermal stress relaxation layer 22 or the heat shielding layer 23 is adjusted by adjusting the stacking amount of the zirconium oxide ingot 41 or the hafnium oxide ingot 42 other than the portion in contact with the predetermined angle θ. Can be adjusted. Further, depending on the characteristics required for the base material 20 to be coated, such as thermal cycle life, thermal insulation characteristics, thermal shock resistance, etc., the ingot 40 is appropriately contacted at the predetermined angle θ or the predetermined angle θ. Coating can be performed by adjusting the stacking amount of the zirconium oxide ingot 41 or the hafnium oxide ingot 42 other than the portion where the metal oxide is in.

  As described above, according to the ceramic covering member 10 of the first embodiment, the boundary portion 24 between the thermal stress relaxation layer 22 and the thermal insulation layer 23 and the vicinity thereof are changed from the thermal stress relaxation layer 22 to the thermal insulation layer 23. On the other hand, a gradient composition layer in which the concentration of zirconium oxide forming the thermal stress relaxation layer 22 continuously decreases and the concentration of hafnium oxide forming the thermal barrier layer 23 continuously increases can be obtained. As a result, the concentration of thermal stress at the contact portion of the film made of the different material can be relaxed, and the thermal cycle characteristics can be remarkably improved.

  Further, in the ceramic covering member 10, the surface is composed of a heat shielding layer 23 made of hafnium oxide having low heat conductivity and excellent heat resistance, and is laminated on the heat shielding layer 23, and the metal layer side is more thermally expanded than hafnium oxide. By comprising the thermal stress relaxation layer 22 made of zirconium oxide having a high thermal conductivity and low thermal conductivity, it is possible to maintain excellent heat shielding characteristics even when used at a high temperature for a long time.

  In addition, the ceramic-coated member 10 having the above-described gradient composition layer (the boundary portion 24 and the vicinity thereof) has the zirconium oxide ingot 41 and the hafnium oxide so that the first evaporation side becomes the zirconium oxide ingot 41 in the electron beam physical vapor deposition. An ingot 40 is configured such that ingots 42 are stacked in a columnar shape, and a contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42 has a predetermined angle θ with respect to the central axis of the columnar stacked body. It can manufacture by using.

(Second Embodiment)
FIG. 3 is a view showing a cross section of the ceramic-coated member 60 of the second embodiment. In addition, the same code | symbol is attached | subjected to the component same as the structure of the ceramic coating | coated member 10 of 1st Embodiment, and the overlapping description is abbreviate | omitted or simplified.

  As shown in FIG. 3, the ceramic covering member 60 includes a base material 20, an antioxidant layer 21 laminated on the base material 20, an oxygen barrier layer 70 laminated on the antioxidant layer 21, and this oxygen barrier. The thermal stress relaxation layer 22 laminated | stacked on the layer 70 and the thermal-insulation layer 23 laminated | stacked on this thermal stress relaxation layer 22 are provided.

  Further, in the boundary portion 71 between the oxygen barrier layer 70 and the thermal stress relaxation layer 22 and its vicinity, the concentration of the ceramic material forming the oxygen barrier layer 70 is continuous from the oxygen barrier layer 70 toward the thermal stress relaxation layer 22. In addition, the concentration of the ceramic material forming the thermal stress relaxation layer 22 increases continuously. Further, in the boundary portion 24 between the thermal stress relaxation layer 22 and the thermal barrier layer 23 and its vicinity, the concentration of the ceramic material forming the thermal stress relaxation layer 22 is continuous from the thermal stress relaxation layer 22 toward the thermal barrier layer 23. And the concentration of the ceramic material forming the heat shield layer 23 increases continuously. This boundary portion 71 and its vicinity function as a boundary layer.

The oxygen barrier layer 70 is excellent in preventing oxygen from being transmitted from the outside to the antioxidant layer 21 side, and is composed of a ceramic material mainly composed of zirconium oxide that forms the thermal stress relaxation layer 22 and an oxidation that forms the thermal barrier layer 23. It is a film made of a ceramic material having a thermal expansion coefficient larger than that of a ceramic material mainly composed of hafnium. As the ceramic material for forming this film, for example, a stabilized aluminum oxide-based ceramic material mainly composed of aluminum oxide (Al ₂ O ₃ ) is used.

  Further, in the boundary portion 71 between the oxygen barrier layer 70 and the thermal stress relaxation layer 22 and its vicinity, the concentration of aluminum oxide forming the oxygen barrier layer 70 is continuous from the oxygen barrier layer 70 toward the thermal stress relaxation layer 22. In addition, the concentration of zirconium oxide forming the thermal stress relaxation layer 22 increases continuously. In other words, the boundary portion 71 between the oxygen barrier layer 70 and the thermal stress relaxation layer 22 and its vicinity form a gradient composition layer in which the concentrations of aluminum oxide and zirconium oxide continuously change in the thickness direction. Further, in the boundary portion 24 between the thermal stress relaxation layer 22 and the thermal barrier layer 23 and its vicinity, the concentration of zirconium oxide forming the thermal stress relaxation layer 22 is continuous from the thermal stress relaxation layer 22 toward the thermal barrier layer 23. In addition, the concentration of hafnium oxide forming the heat shielding layer 23 increases continuously. That is, the boundary portion 24 between the thermal stress relaxation layer 22 and the heat shielding layer 23 and its vicinity form a gradient composition layer in which the concentrations of zirconium oxide and hafnium oxide continuously change in the thickness direction.

  Next, a manufacturing method of the ceramic covering member 60 will be described with reference to FIG.

  FIG. 4 is a cross-sectional view showing an outline of electron beam physical vapor deposition for manufacturing the ceramic covering member 60.

  First, the antioxidant layer 21 made of the above metal material is formed on the surface of the substrate 20 by plasma spraying or the like.

  Subsequently, the oxygen barrier layer 70, the thermal stress relaxation layer 22, and the thermal barrier layer 23 formed on the antioxidant layer 21 are formed by electron beam physical vapor deposition. Hereinafter, a method for forming the oxygen barrier layer 70, the thermal stress relaxation layer 22, and the thermal barrier layer 23 will be described in more detail.

  In this electron beam physical vapor deposition, an ingot 65 formed of ceramics is irradiated with an electron beam 45 in a vacuum, and the surface of the oxidation layer 21 heated to a high temperature is dissolved on the surface of the oxidation layer 21 by melting the ingot surface and evaporating vapor 67. Apply. At this time, as shown in FIG. 4, the base material 20 is rotated at a constant speed in a predetermined direction with the central axis of the base material 20 as a rotation axis so that the surface of the antioxidant layer 21 can be uniformly coated with ceramics. It has become.

  In the ingot 65, an aluminum oxide ingot 66, a zirconium oxide ingot 41, and a hafnium oxide ingot 42 are stacked in this order in a column shape in the water-cooled crucible 50 so that the first evaporation side becomes the aluminum oxide ingot 66. ing. Further, the contact surface between the aluminum oxide ingot 66 and the zirconium oxide ingot 41 and the contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42 respectively have predetermined angles θ and γ with respect to the central axis of the columnar laminate. It is configured.

  Here, the predetermined angle θ and the predetermined angle γ are preferably 45 to 85 degrees, respectively. The predetermined angles θ and γ are preferable when the gradient composition layer is thicker when the angle is less than 45 degrees, and when the angle exceeds 85 degrees, the effect of providing an angle on the contact surface is impaired, and the continuous gradient composition is obtained. Will not be formed. In addition, since the thermal conductivity of the gradient composition layer is high, it is desirable that the gradient composition layer is thin.

  As described above, the contact surface between the aluminum oxide ingot 66 and the zirconium oxide ingot 41 is configured to have a predetermined angle γ with respect to the central axis of the columnar laminate, and this portion becomes the evaporated vapor 67. In this case, the vaporized vapor 67 having a composition containing both components of aluminum oxide and zirconium oxide can be formed. The component composition of the vaporized vapor 67 when the portion of the ingot 65 having the predetermined angle γ evaporates is such that the concentration of aluminum oxide continuously decreases and the concentration of zirconium oxide continuously increases. As a result, the concentration of aluminum oxide forming the oxygen barrier layer 70 continuously decreases between the oxygen barrier layer 70 and the thermal stress relaxation layer 22 from the oxygen barrier layer 70 toward the thermal stress relaxation layer 22. A gradient composition layer in which the concentration of zirconium oxide forming the thermal stress relaxation layer 22 continuously increases is formed.

  Further, by forming the contact surface of the zirconium oxide ingot 41 and the hafnium oxide ingot 42 with a predetermined angle θ with respect to the central axis of the columnar laminate, when this portion becomes the evaporated vapor 67, An evaporating vapor 67 having a composition containing both components of zirconium oxide and hafnium oxide can be formed. The component composition of the vaporized vapor 67 when the portion of the ingot 65 having the predetermined angle θ evaporates is such that the concentration of zirconium oxide continuously decreases and the concentration of hafnium oxide continuously increases. As a result, the concentration of zirconium oxide forming the thermal stress relaxation layer 22 continuously decreases between the thermal stress relaxation layer 22 and the thermal barrier layer 23 from the thermal stress relaxation layer 22 toward the thermal barrier layer 23. At the same time, a gradient composition layer in which the concentration of hafnium oxide that forms the heat shielding layer 23 continuously increases is formed.

  Further, by adjusting the predetermined angles θ and γ, the thickness of the gradient composition layer, the concentration gradient of aluminum oxide and zirconium oxide, and the concentration gradient of zirconium oxide and hafnium oxide in the gradient composition layer can be adjusted. Can do. Further, in the ingot 65, the oxygen barrier layer 70, the thermal stress relaxation layer 22 and the shielding layer 22 are adjusted by adjusting the amount of lamination of the ingots 41, 42 and 66 other than the portions in contact with the predetermined angles θ and γ. The thickness of the thermal layer 23 can be adjusted. Further, depending on the characteristics required for the substrate 20 to be coated, such as thermal cycle life, thermal insulation characteristics, thermal shock resistance, and the like, the predetermined angles θ and γ in the ingot 40 and the predetermined angles θ and γ are appropriately selected. It is possible to apply the coating by adjusting the stacking amount of the aluminum oxide ingot 66, the zirconium oxide ingot 41 or the hafnium oxide ingot 42 other than the portions in contact with each other.

  As described above, according to the ceramic covering member 60 of the second embodiment, the boundary 71 between the oxygen barrier layer 70 and the thermal stress relaxation layer 22 and the vicinity thereof are changed from the oxygen barrier layer 70 to the thermal stress relaxation layer 22. On the other hand, a gradient composition layer in which the concentration of aluminum oxide forming the oxygen barrier layer 70 continuously decreases and the concentration of zirconium oxide forming the thermal stress relaxation layer 22 continuously increases can be obtained. As a result, the concentration of thermal stress at the contact portion of the film made of the different material can be relaxed, and the thermal cycle characteristics can be remarkably improved.

  Further, the concentration of zirconium oxide forming the thermal stress relaxation layer 22 is continuously increased from the thermal stress relaxation layer 22 toward the heat shield layer 23 at the boundary portion 24 between the thermal stress relaxation layer 22 and the thermal barrier layer 23 and the vicinity thereof. And the gradient composition layer in which the concentration of hafnium oxide forming the heat shielding layer 23 continuously increases. As a result, the concentration of thermal stress at the contact portion of the film made of the different material can be relaxed, and the thermal cycle characteristics can be remarkably improved.

  Further, in the ceramic covering member 10, the surface is constituted by a heat shielding layer 23 made of hafnium oxide having low heat conductivity and excellent heat resistance, and the thermal expansion coefficient is higher than that of hafnium oxide on the metal layer side of the heat shielding layer 23. A thermal stress relaxation layer 22 made of zirconium oxide having a large low thermal conductivity is formed, and an oxygen barrier layer 70 made of aluminum oxide having a thermal expansion coefficient larger than that of zirconium oxide is formed on the metal layer side of the thermal stress relaxation layer 22. Thus, even when used at a high temperature for a long time, excellent heat shielding characteristics are maintained and excellent thermal cycle characteristics are obtained.

  Further, the ceramic covering member 60 having the above-described gradient composition layer (each of the boundary portions 24 and 71 and the vicinity thereof) has an aluminum oxide ingot 66 so that the first evaporation side becomes the aluminum oxide ingot 66 in the electron beam physical vapor deposition. The zirconium oxide ingot 41 and the hafnium oxide ingot 42 are stacked in this order in a columnar shape, and the contact surface between the aluminum oxide ingot 66 and the zirconium oxide ingot 41 and the contact between the zirconium oxide ingot 41 and the hafnium oxide ingot 42 are arranged. The surface can be manufactured by using an ingot 65 configured to have predetermined angles θ and γ with respect to the central axis of the columnar laminate.

  Next, the ceramic according to the present invention, in which the contact surface of each of the ingots made of ceramic is coated with a ceramic using an ingot configured to have an angle of 45 to 85 degrees with respect to the central axis of the columnar laminate. It demonstrates that a coating | coated member has the outstanding heat cycle characteristic.

Example 1
A method for producing the test piece 1 used in Example 1 will be described with reference to a cross-sectional view showing an outline of electron beam physical vapor deposition for producing the ceramic-coated member 10 shown in FIG.

  First, from a Ni-Co base alloy having excellent corrosion resistance and oxidation resistance by plasma spraying on the surface of a disk-shaped substrate 20 made of a Ni base superalloy having a diameter of 2.54 cm (1 inch) and a thickness of 5 mm. An antioxidant layer 21 having a thickness of about 100 μm was formed.

  The base material 20 on which the antioxidant layer 21 was formed was mounted in a vacuum chamber of an electron beam physical vapor deposition apparatus so as to be rotatable about the center of the disk-shaped base material 20 as a rotation axis. Here, the base material 20 was rotated at about 10 rpm. In addition, the zirconium oxide ingot 41 and the hafnium oxide ingot 42 are stacked in a columnar shape in the water-cooled crucible 50 in the vacuum chamber so that the first evaporation side is the zirconium oxide ingot 41. At this time, the contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42 was formed to be 85 degrees with respect to the central axis of the columnar laminate.

  After vacuuming the inside of the vacuum chamber using the ingot 40, the surface of the zirconium oxide ingot 41 of the ingot 40 inserted in the water-cooled crucible 50 is irradiated with the electron beam 45 to melt and evaporate the zirconium oxide. The thermal stress relaxation layer 22 made of zirconium oxide was formed on the surface of the antioxidant layer 21 by using steam 46. Subsequently, the ingot 40 gradually melts and evaporates, reaches an area including the contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42, generates an evaporation vapor 46 including both zirconium oxide and hafnium oxide, A gradient composition layer was formed at and near the boundary 24 between the stress relaxation layer 22 and the heat shield layer 23. In the process of forming the thermal stress relaxation layer 22 and the gradient composition layer described above, the temperature of the substrate 20 was maintained at 850 to 900 ° C.

  Further, the ingot 40 was melted and evaporated to reach a region consisting only of the hafnium oxide ingot 42, and the hafnium oxide was melted to form the evaporated vapor 46, thereby forming the heat shielding layer 23 made of hafnium oxide. In the process of forming the heat shield layer 23, the temperature of the substrate 20 was maintained at 900 to 950 ° C.

  Then, the electron beam 45 was stopped immediately before the hafnium oxide ingot 42 was completely evaporated and consumed.

  The thickness of the thermal stress relaxation layer 22 formed in the above-described electron beam physical vapor deposition is about 200 μm, and the thickness of the gradient composition layer formed in the vicinity of the boundary portion 24 is about 24 μm. The thickness of 23 was about 100 μm.

  A thermal cycle test was carried out using the test piece 1 produced by the method described above. In the thermal cycle test, the test piece 1 was left to heat for 30 minutes in an electric furnace maintained at a temperature of 1100 ° C., and then left in the atmosphere until the temperature reached 100 ° C. Subsequently, the test piece 1 having a temperature of 100 ° C. was again left in the electric furnace for 30 minutes and heated, and then left in the atmosphere until the temperature reached 100 ° C. Thus, heating and cooling were repeated, and the number of repetitions until the ceramic layer of the test piece 1 was peeled was measured.

  Here, Table 1 shows the results of the thermal cycle test. The number of white circles and black circles in Table 1 means the number of times the thermal cycle test was performed under the same conditions. A white circle means that no damage has occurred in the corresponding number of repetitions, and a black circle means that peeling or local swelling has occurred in the corresponding number of repetitions.

  As shown in Table 1, in the test piece 1, damage (peel peeling) occurred in one of the two test pieces 1 carried out under the same conditions when the number of repetitions was 100 times. Moreover, damage (peel peeling) occurred when the number of repetitions was 125 times.

(Example 2)
The test piece 2 used in Example 2 used an ingot 40 formed such that the contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42 was 80 degrees with respect to the central axis of the columnar laminate. Except for the above, the test piece 1 was produced in the same manner as the test piece 1 in Example 1.

  Further, in the manufactured test piece 2, the thickness of the thermal stress relaxation layer 22 is about 200 μm, the thickness of the gradient composition layer formed in the vicinity of the boundary portion 24 is about 36 μm, and the heat shielding layer 23. The thickness of was about 100 μm. The thermal cycle test method and measurement conditions are the same as the test method and measurement conditions in Example 1.

  As shown in Table 1, in the test piece 2, when the number of repetitions was 125, damage (peel peeling) occurred in one of the two test pieces 1 performed under the same conditions. Moreover, damage (peel peeling) occurred when the number of repetitions was 150 times.

Example 3
The test piece 3 used in Example 3 used an ingot 40 formed so that the contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42 was 75 degrees with respect to the central axis of the columnar laminate. Except for the above, the test piece 1 was produced in the same manner as the test piece 1 in Example 1.

  In the prepared test piece 3, the thickness of the thermal stress relaxation layer 22 is about 200 μm, the thickness of the gradient composition layer formed in the vicinity of the boundary portion 24 and the vicinity thereof is about 50 μm, and the heat shielding layer 23. The thickness of was about 100 μm. The thermal cycle test method and measurement conditions are the same as the test method and measurement conditions in Example 1.

  As shown in Table 1, in the test piece 3, when the number of repetitions was 200, damage (peel peeling) occurred in one of the two test pieces 1 performed under the same conditions.

  Moreover, the cross section of the test piece 3 was observed using the scanning electron microscope (SEM: Scanning Electron Microscope). Furthermore, using an EPMA (Electron prove micro analyzer), an element distribution measurement of the boundary portion 24 and its vicinity in the test piece 3 was performed. The results of these observations and element distribution measurements will be described later.

Example 4
A method for producing the test piece 4 used in Example 4 will be described with reference to a cross-sectional view showing an outline of electron beam physical vapor deposition for producing the ceramic-coated member 60 shown in FIG.

  First, from a Ni-Co base alloy having excellent corrosion resistance and oxidation resistance by plasma spraying on the surface of a disk-shaped substrate 20 made of a Ni base superalloy having a diameter of 2.54 cm (1 inch) and a thickness of 5 mm. An antioxidant layer 21 having a thickness of about 100 μm was formed.

  The base material 20 on which the antioxidant layer 21 was formed was mounted in a vacuum chamber of an electron beam physical vapor deposition apparatus so as to be rotatable about the center of the disk-shaped base material 20 as a rotation axis. Here, the base material 20 was rotated at about 10 rpm. Further, in the water-cooled crucible 50 in the vacuum chamber, an aluminum oxide ingot 66, a zirconium oxide ingot 41, and a hafnium oxide ingot 42 are laminated in this order in a column shape so that the first evaporation side becomes the aluminum oxide ingot 66. Arranged. At this time, the contact surface between the aluminum oxide ingot 66 and the zirconium oxide ingot 41 and the contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42 are respectively set to 85 degrees with respect to the central axis of the columnar laminate. Formed.

  After vacuuming the inside of the vacuum chamber using the ingot 65, the surface of the aluminum oxide ingot 66 of the ingot 65 inserted into the water-cooled crucible 50 is irradiated with the electron beam 45 to melt and evaporate the aluminum oxide. Vapor 67 was used to form an oxygen barrier layer 70 made of aluminum oxide on the surface of the antioxidant layer 21. Subsequently, the ingot 65 gradually melts and evaporates, reaches an area including the contact surface between the aluminum oxide ingot 66 and the zirconium oxide ingot 41, generates an evaporation vapor 67 including both aluminum oxide and zirconium oxide, and is inclined. A composition layer was formed at the boundary portion 71 and its vicinity. In the process of forming the oxygen barrier layer 70 and the gradient composition layer described above, the temperature of the substrate 20 was maintained at 600 to 800 ° C.

  Further, the ingot 65 was melted and evaporated to reach a region consisting only of the zirconium oxide ingot 41, and the zirconium oxide was melted to form an evaporated vapor 67 to form the thermal stress relaxation layer 22 made of zirconium oxide. Subsequently, the ingot 40 gradually melts and evaporates, reaches an area including the contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42, generates an evaporated vapor 67 including both zirconium oxide and hafnium oxide, and is inclined. A composition layer was formed at the boundary 24 and its vicinity. In the process of forming the thermal stress relaxation layer 22 and the gradient composition layer described above, the temperature of the substrate 20 was maintained at 700 to 900 ° C.

  Further, the ingot 65 was melted and evaporated to reach a region consisting only of the hafnium oxide ingot 42, and the hafnium oxide was melted to form an evaporated vapor 67 to form the heat shielding layer 23 made of hafnium oxide. In the process of forming the heat shield layer 23, the temperature of the substrate 20 was maintained at 750 to 950 ° C.

  Then, the electron beam 45 was stopped immediately before the hafnium oxide ingot 42 was completely evaporated and consumed.

  The thickness of the oxygen barrier layer 70 formed in the above-described electron beam physical vapor deposition is about 20 μm, the thickness of the thermal stress relaxation layer 22 is about 200 μm, and the thickness of the gradient composition layer is about 24 μm. The thickness of the heat shield layer 23 was about 100 μm.

  A thermal cycle test was carried out using the test piece 4 produced by the method described above. The thermal cycle test method and measurement conditions are the same as the test method and measurement conditions in Example 1.

  As shown in Table 1, the test piece 4 was not damaged even when the number of repetitions was 200.

(Comparative Example 1)
The test piece 5 used in Comparative Example 1 used an ingot 40 formed such that the contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42 was 90 degrees with respect to the central axis of the columnar laminate. Except for the above, the test piece 1 was produced in the same manner as the test piece 1 in Example 1. Here, when the contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42 is 90 degrees with respect to the central axis of the columnar laminate, the contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42 is horizontal. Means that

  Moreover, in the produced test piece 5, the thickness of the thermal stress relaxation layer 22 was about 100 micrometers, and the thickness of the thermal insulation layer 23 was about 100 micrometers. The thermal cycle test method and measurement conditions are the same as the test method and measurement conditions in Example 1.

  As shown in Table 1, in the test piece 5, when the number of repetitions was 30, damage (peel peeling) occurred on one of the two test pieces 1 performed under the same conditions. Moreover, damage (peel peeling) occurred when the number of repetitions was 75 times.

(Comparative Example 2)
The test piece 6 used in Comparative Example 2 was manufactured using an ingot in which the positions of the zirconium oxide ingot 41 and the hafnium oxide ingot 42 of the ingot 40 used in Example 1 were reversed. That is, the test piece 6 uses an ingot in which a hafnium oxide ingot 42 and a zirconium oxide ingot 41 are stacked in a columnar shape in a water-cooled crucible 50 so that the first evaporation side becomes the hafnium oxide ingot 42. It was made. The ingot was formed such that the contact surface between the hafnium oxide ingot 42 and the zirconium oxide ingot 41 was 85 degrees with respect to the central axis of the columnar laminate.

  Using this ingot, the inside of the vacuum chamber described above is evacuated, and then the electron beam 45 is irradiated on the surface of the hafnium oxide ingot 42 of the ingot inserted into the water-cooled crucible 50 to melt the hafnium oxide and evaporate vapor 46. Then, a coating layer made of hafnium oxide was formed on the surface of the antioxidant layer 21. Subsequently, the ingot gradually melts and evaporates, reaches an area including the contact surface between the hafnium oxide ingot 42 and the zirconium oxide ingot 41, generates an evaporated vapor 46 including both hafnium oxide and zirconium oxide, and has a gradient composition. A layer was formed at and near the boundary 24. In the process of forming the coating layer and the gradient composition layer described above, the temperature of the substrate 20 was maintained at 750 to 950 ° C.

  Further, the ingot was melted and evaporated to reach the region consisting only of the zirconium oxide ingot 41, and the zirconium oxide was melted to form the evaporated vapor 46 to form a coating layer made of zirconium oxide. In the process of forming the coating layer, the temperature of the substrate 20 was maintained at 700 to 900 ° C.

  Then, the electron beam 45 was stopped immediately before the zirconium oxide ingot 41 was completely evaporated and consumed.

  The thickness of the coating layer made of hafnium oxide formed in the above-described electron beam physical vapor deposition is about 100 μm, the thickness of the gradient composition layer is about 24 μm, and the thickness of the coating layer made of zirconium oxide is about 200 μm. Met.

  A thermal cycle test was carried out using the test piece 6 produced by the method described above. The thermal cycle test method and measurement conditions are the same as the test method and measurement conditions in Example 1.

  As shown in Table 1, in the test piece 6, the number of repetitions was 10, and damage (peel peeling) occurred on both of the two test pieces carried out under the same conditions.

(Summary of Examples 1 to 4 and Comparative Examples 1 to 2)
As shown in Table 1, it was found that the test pieces (test pieces 1 to 4) used in Examples 1 to 4 according to the present invention showed good thermal cycle characteristics. Further, from the results of Example 4, it was found that better thermal cycle characteristics can be obtained by providing the oxygen barrier layer 70 made of aluminum oxide between the antioxidant layer 21 and the thermal stress relaxation layer 22. .

  Further, from the results in Examples 1 to 3 according to the present invention, the smaller the angle θ formed between the contact surface of the zirconium oxide ingot 41 and the hafnium oxide ingot 42 with respect to the central axis of the columnar laminate, the better. It was found to exhibit thermal cycle characteristics. As the angle θ decreases, the tendency of the composition to discontinuously change as shown in FIGS. 11A and 11B decreases and becomes continuous, and the concentration of thermal stress at the interface between different materials is reduced. It is thought that it was because of.

  Here, FIG. 5 shows a backscattered electron image as a result of observing a cross section of the test piece 3 in Example 3 with an SEM. In addition, FIG. 6 shows the results of the element distribution measurement performed in Example 3 on the boundary portion 24 and its vicinity in the test piece 3.

  As shown in FIG. 5, it was found that a region having a configuration different from each layer exists between the thermal barrier layer 23 and the thermal stress relaxation layer 22 in the boundary portion 24 and the vicinity thereof. Further, from the result of the element distribution measurement shown in FIG. 6, the boundary 24 and the vicinity thereof correspond to the concentration of zirconium oxide forming the thermal stress relaxation layer 22 from the thermal stress relaxation layer 22 toward the thermal barrier layer 23. It has been clarified that the strength of hafnium corresponding to the concentration of hafnium oxide forming the heat shielding layer 23 continuously increases as the strength of zirconium decreases continuously. That is, it has been clarified that a gradient composition layer in which the concentrations of zirconium oxide and hafnium oxide continuously change is formed in the boundary portion 24 and the vicinity thereof.

  FIG. 7 shows an angle θ formed by the contact surface between the zirconium oxide ingot 41 and the hafnium oxide ingot 42 with respect to the central axis of the columnar laminate, and an inclination formed when the ingot 40 having that angle is used. The relationship with the thickness of a composition layer is shown. In addition, when the angle is 85 degrees, the thickness of the gradient composition layer of the test piece 1, when the angle is 80 degrees, the thickness of the gradient composition layer of the test piece 2, and when the angle is 75 degrees, the test piece 3 Respectively corresponding to the thickness of the gradient composition layer.

  As shown in FIG. 7, it became clear that the thickness of the boundary portion 24 and its vicinity, that is, the thickness of the gradient composition layer can be controlled by changing the angle θ. It was also found that the gradient composition layer can be made thinner by increasing the angle θ, while the gradient composition layer can be made thicker by reducing the angle θ. Accordingly, an appropriate thickness of the gradient composition layer can be set in accordance with characteristics required for a ceramic-coated member, such as thermal cycle life, thermal insulation characteristics, and thermal shock resistance.

Further, in the test piece 6 in Comparative Example 2 provided with the coating layer made of zirconium oxide on the coating layer made of hafnium oxide, a good gradient composition layer was formed at both the boundary portions and in the vicinity thereof (illustrated). No), and the heat cycle life was significantly inferior to the test pieces of Examples 1 to 3 (Test pieces 1 to 3). This result shows that the thermal expansion coefficient of hafnium oxide (about 6 × 10 ⁻⁶ / ° C.) is the same as that of zirconium oxide (about 10 × 10 ⁻⁶ / ° C.) or the thermal expansion coefficient of the metal base (15 × 10 ^{This is probably} because a large thermal stress was generated in the coating layer made of zirconium oxide having a small thermal expansion coefficient and a thermal expansion coefficient of about ⁻⁶ / ° C. and the coating layer made of hafnium oxide sandwiched between metal substrates. Therefore, in order to suppress the thermal stress generated in each layer, as in the test pieces (test pieces 1 to 3) of Examples 1 to 3, the thermal expansion coefficient of each layer is from the metal substrate side toward the surface. It has been found that it is effective to select materials so that they gradually become smaller.

  Although the present invention has been specifically described above with reference to the embodiments, the present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the invention.

  DESCRIPTION OF SYMBOLS 10 ... Ceramics coating member, 20 ... Base material, 21 ... Antioxidation layer, 22 ... Thermal stress relaxation layer, 23 ... Thermal insulation layer, 24 ... Boundary part, 40 ... Ingot, 41 ... Zirconium oxide ingot, 42 ... Hafnium oxide ingot 45 ... Electron beam, 46 ... Evaporated vapor, 50 ... Water-cooled crucible.

Claims (7)

A ceramic covering member configured by laminating at least a thermal stress relaxation layer and a thermal barrier layer in this order on a base material made of metal or ceramic by electron beam physical vapor deposition,
In the boundary layer between the thermal stress relaxation layer and the thermal barrier layer, the concentration of the first ceramic material forming the thermal stress relaxation layer continuously decreases from the thermal stress relaxation layer toward the thermal barrier layer. And the concentration of the second ceramic material forming the heat-insulating layer continuously increases.   2. The ceramic-coated member according to claim 1, wherein an antioxidant layer made of a metal is interposed between the base material and the thermal stress relaxation layer. A ceramic-coated member formed by laminating at least an oxygen barrier layer, a thermal stress relaxation layer, and a thermal barrier layer in this order on a base material made of metal or ceramics by electron beam physical vapor deposition,
In the boundary layer between the oxygen barrier layer and the thermal stress relaxation layer, the concentration of the third ceramic material forming the oxygen barrier layer continuously decreases from the oxygen barrier layer toward the thermal stress relaxation layer. And the concentration of the first ceramic material forming the thermal stress relaxation layer continuously increases,
And in the boundary layer between the thermal stress relaxation layer and the thermal barrier layer, the concentration of the first ceramic material forming the thermal stress relaxation layer is continuously from the thermal stress relaxation layer toward the thermal barrier layer. A ceramic-coated member characterized by decreasing and continuously increasing the concentration of the second ceramic material forming the heat-shielding layer.   4. The ceramic-coated member according to claim 3, wherein an antioxidant layer made of a metal is interposed between the base material and the oxygen barrier layer.   5. The ceramic-coated member according to claim 1, wherein a thermal expansion coefficient of the first ceramic material is larger than a thermal expansion coefficient of the second ceramic material.   The ceramic-coated member according to any one of claims 1 to 5, wherein the first ceramic material contains zirconium oxide as a main component, and the second ceramic material contains hafnium oxide as a main component.   The ceramic-coated member according to claim 3 or 4, wherein the third ceramic material contains aluminum oxide as a main component.

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