JP2006124734A - Film material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film material having the heat conductivity smaller than that of zirconia without any problem of the phase transition. <P>SOLUTION: A film having low heat conductivity and peeling resistance is realized by using a compound of high dielectric constant for a film material. More specifically, a thermal barrier coating material mainly contains a dielectric having the refractive index of ≥ 2.2 at the temperature of 25°C and the wavelength of 600 nm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermal barrier coating material applicable to equipment parts used in a high temperature environment such as a moving blade, stationary blade, combustor, and jet engine of a gas turbine for power generation.

  In order to improve the efficiency of gas turbines, jet engines, etc., the combustion gas has been getting hotter. Therefore, in order to protect metal parts from high temperature (for example, the blade surface temperature is about 1400 ° C. in a 1500 ° C. class gas turbine), a thermal barrier coating (TBC) is applied to the surface of the parts. As a material for this thermal barrier coating, practically, only a low thermal conductive ceramic such as rare earth stabilized zirconia such as yttria stabilized zirconia (YSZ) is used (see, for example, Patent Document 1). The thermal barrier coating is applied by atmospheric pressure plasma spraying on a base material that is a metal part, after a metal bonding layer is applied by low pressure plasma spraying or the like.

  Thermal barrier coatings applied to metal parts by atmospheric pressure plasma spraying have many pores inside rather than a dense structure. FIG. 1 shows a schematic diagram of the structure of the thermal barrier coating. As shown in FIG. 1, the structure of the thermal barrier coating 1 includes atmospheric pores 2 with a diameter of several tens of μm, small pores 3 with a diameter of about several μm, linear pores 4 and 5 with a narrow width, etc. There are various types of pores. At the same time as the thermal barrier coating 1 itself is a low thermal conductive ceramic, the heat insulating performance of the material is maintained by such a large number of pores 2 to 5 existing inside, and the high temperature of the metal part as the base material is high. It can be used in an environment.

  Since the Carnot efficiency is improved by 1% or more by increasing the temperature to 100 ° C. by the thermal barrier coating, a coating material having a high thermal barrier capability is required.

There is also a report that a material having a cubic pyrochlore structure such as La ₂ Zr ₂ O ₇ is applied as a thermal barrier coating material replacing zirconia (see Patent Documents 2 to 4). According to the literature, La ₂ Zr ₂ O ₇ is said to be suitable as a thermal barrier coating material because its thermal conductivity is smaller than that of zirconia. However, since La ₂ Zr ₂ O _{7 has} a thermal expansion coefficient smaller than that of zirconia, it actually has a problem that a tensile stress will remain between the metal parts as the base material.

JP 2003-026475 A Japanese Patent Laid-Open No. 10-212108 European Patent No. 0848077 US Pat. No. 6,117,560

  As described above, the material used for the thermal barrier coating is required to have as low a thermal conductivity as possible.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a novel thermal barrier coating material having a thermal conductivity smaller than that of zirconia.

  As described above, in order to provide a material having a melting point higher than the use temperature and a low thermal conductivity as a new thermal barrier coating material instead of zirconia, the present inventors use first-principles calculations. Searched. The “first-principles calculation” is a method for obtaining various physical property values on the nanometer scale by changing the conditions for solving the basic equations of quantum mechanics.

The present inventors have found for the first time that there is a correlation between a high dielectric constant compound and low thermal conductivity. A compound with a high dielectric constant is likely to cause oxygen deficiency because the electron cloud is easily deformed, and this is thought to be because the mean free path of phonons is shortened. The refractive index of zirconia is reported to be 2.1 to 2.2, and the dielectric constant at room temperature (25 ° C.) is 23 at 1 MHz. La ₂ Zr ₂ O ₇ has been reported to have a refractive index of 2.09 and a dielectric constant of 10 at 1 MHz at room temperature (25 ° C.), but a material having a higher refractive index and dielectric constant is considered desirable.

  As a result of further research and synthesis of various high dielectric constant compounds, it became clear that the high dielectric constant compounds exhibit low thermal conductivity.

That is, the present invention provides a thermal barrier coating material having a low thermal conductivity, which mainly contains a dielectric (high dielectric constant compound) having a refractive index of 2.2 or more at a wavelength of 600 nm at 25 ° C.
The refractive index of this dielectric at a wavelength of 600 nm at 25 ° C. is more preferably 2.3 or more, more preferably 2.4 or more, further preferably 2.5 or more, and further preferably 2.6 or more. More preferably, 2.8 or more is more preferable, 2.9 or more is more preferable, 3.0 or more is more preferable, and 4.0 or more is most preferable. This is because the higher the refractive index, the lower the thermal conductivity of the thermal barrier coating material.

The present invention also provides a thermal barrier coating material having a low thermal conductivity, characterized by mainly comprising a dielectric having a dielectric constant of 35 or more at 25 ° C. and a frequency of 1 MHz.
The dielectric constant of this dielectric at 25 ° C. and a frequency of 1 MHz is more preferably 45 or more, more preferably 55 or more, further preferably 65 or more, further preferably 75 or more, further preferably 85 or more, and further preferably 95 or more. 200 or more is more preferable, and 300 or more is most preferable. This is because the higher the dielectric constant, the lower the thermal conductivity of the thermal barrier coating material.
The dielectric constant is usually expressed as a complex number composed of a real part and an imaginary part, but the dielectric suitably used in the present invention has an imaginary part whose absolute value is close to 0. It will be ignored.
In the present invention, the “refractive index” and “dielectric constant” of the dielectric represent a refractive index and a dielectric constant measured in a state where the dielectric does not include pores.

  The thermal barrier coating material of the present invention exhibits sufficiently low thermal conductivity even when used alone. In addition, it is presumed that the thermal barrier coating material of the present invention is sufficiently suitable as the thermal barrier coating material because it is presumed that the low thermal conductivity will not be impaired even if they are used in combination.

  According to the present invention, by providing a thermal barrier coating material having a low thermal conductivity by using a high dielectric constant compound, a material suitable for a thermal barrier coating film exhibiting a low thermal conductivity as compared to the current zirconia. Can be provided.

  Further, according to the present invention, a thermal barrier coating material having low thermal conductivity is provided by using a high dielectric constant compound, and the thermal conductivity is further improved by including a composite material of each. A range-controlled thermal barrier coating material can be provided.

  Embodiments of the present invention will be described below.

[Example 1]
Mn _0.91 Zn _0.09 Fe ₂ O ₄ has a high refractive index of 4.65. The starting materials were weighed so as to have a predetermined ratio, and solid phase mixed using a ball mill. After drying the mixed powder, it was calcined at 1400 ° C. When the calcined powder was identified by powder X-ray diffraction, it was confirmed that no unreacted raw material component remained and it was in a single phase.
The sample was fired at 1600 ° C., a disk-shaped sample having a diameter of 10 mmφ and a thickness of 1 mm was cut out from the sintered body, and the thermal conductivity was measured by a laser flash method. The thermal conductivity was 0.9 [W / mK], which was a physical property value suitable as a thermal barrier coating.

[Example 2]
YBa ₂ Cu ₃ O _x has a large refractive index of 4.5. The starting materials were weighed so as to have a predetermined ratio, and solid phase mixed using a ball mill. After drying the mixed powder, it was calcined at 1400 ° C. When the calcined powder was identified by powder X-ray diffraction, it was confirmed that no unreacted raw material component remained and it was in a single phase.
The sample was fired at 1600 ° C., a disk-shaped sample having a diameter of 10 mmφ and a thickness of 1 mm was cut out from the sintered body, and the thermal conductivity was measured by a laser flash method. The thermal conductivity was 0.91 [W / mK], which was a physical property value suitable as a thermal barrier coating.

[Example 3]
Bi ₃ TiNbO ₉ was fired at 1600 ° C., a disk-shaped sample having a diameter of 10 mmφ and a thickness of 1 mm was cut out from the sintered body, and the thermal conductivity was measured by a laser flash method. The thermal conductivity was 0.8 [W / mK], and the physical property value suitable as a thermal barrier coating was shown.

[Example 4]
SrBi ₂ Nb ₂ O ₉ was fired at 1600 ° C., a disk-shaped sample having a diameter of 10 mmφ and a thickness of 1 mm was cut out from the sintered body, and the thermal conductivity was measured by a laser flash method. The thermal conductivity was 0.81 [W / mK], and the physical property value suitable as a thermal barrier coating was shown.

[Example 5]
A study was made to combine low thermal conductivity materials according to the present invention.

The thermal conductivity (λ _c ) of the composite material is expressed by the following equation (1) called the Maxwell-Eucken equation. In equation (1), λ is thermal conductivity, V is volume fraction, subscript m is a matrix, and subscript p is a phase to be added.

λ _c = λ _m (1 + 2V _p Φ) / (1-V _p Φ) (1)

However, Φ is expressed by the following equation (2).

Φ = (1−λ _m / λ _p ) / (2λ _m / λ _p +1) (2)

By using these equations (1) and (2), the composite thermal conductivity can be calculated when two materials having different thermal conductivities are combined.
Consider, for example, the thermal conductivity when Mn _0.91 Zn _0.09 Fe ₂ O ₄ and Bi ₃ TiNbO ₉ are composited 1: 1. If Mn _0.91 Zn _0.09 Fe ₂ O ₄ is a matrix and Bi ₃ TiNbO ₉ is added, λ _m = 0.9, λ _p = 0.8, and V _p = 0.5. If they are substituted into the equations (1) and (2), the composite thermal conductivity (λ _c ) is λ _c = 0.85.
It becomes. This is a value suitable as a thermal barrier coating.

  Thus, it becomes possible to adjust thermal conductivity by compounding the material of this invention which shows low thermal conductivity. It can be easily estimated that the thermal conductivity can be controlled by conducting the same study on other materials of the present invention.

[Example 6]
Composition formula Nd ₂ Ti ₂ O ₇ , La ₂ Si ₂ O ₇ , La ₂ Ti ₂ O ₇ , Sr ₂ Nb ₂ O ₇ , Sr ₂ Ta ₂ O ₇ , Sr ₃ Ti ₂ O ₇ , La ₂ NiO ₄ , LaTaO _The composition represented by ₄ was selected.

  Then, oxides or carbonates of the respective constituent elements were selected as starting materials, weighed so as to have a predetermined ratio, and solid phase mixed using a ball mill. After drying the mixed powder, it was calcined at 1200 ° C. When the obtained calcined powder was identified by powder X-ray diffraction, it was confirmed that no unreacted raw material component remained and that all samples were in a single phase.

Subsequently, each said sample was baked at 1400 degreeC, the bar-shaped sample of 4x4x15mm was cut out from the sintered compact, and the thermal expansion coefficient was measured. Table 1 shows the values of the coefficient of thermal expansion at 1000 ° C. Note 3YSZ as comparative material _{(3mol% Y 2 O 3 -ZrO} 2: yttria partially stabilized zirconia) value of the thermal expansion coefficient is also shown in the table.

Among the prepared samples, Nd ₂ Ti ₂ O ₇ , Sr ₂ Nb ₂ O ₇ , Sr ₃ Ti ₂ O ₇ , and La ₂ NiO ₄ have a thermal expansion coefficient larger than that of 3YSZ. This suggests that when these materials are used as thermal barrier coatings, they are less likely to generate tensile stress with the underlying metal part than with the current zirconia.

Next, Nd ₂ Ti ₂ O ₇ , La ₂ Si ₂ O ₇ , La ₂ Ti ₂ O ₇ , Sr ₂ Nb ₂ O ₇ , Sr ₂ Ta ₂ O ₇ , Sr ₃ Ti ₂ O ₇ , La ₂ NiO ₄ , LaTaO ₄ was fired at 1400 ° C., a disk-shaped sample having a diameter of 10 mmφ and a thickness of 1 mm was cut out from the sintered body, and the thermal conductivity was measured by a laser flash method. Table 2 shows the values of thermal conductivity at room temperature. In addition, the value (1000 degreeC, literature value) of the thermal conductivity of 3YSZ was also described in the table | surface as a comparative material.

  There is a relationship of the following equation (3) among the thermal conductivity λ of the material, the specific heat C, the mean free path L of the heat transfer medium (phonon), and the motion velocity v. Since the phonon mean free path L is inversely proportional to the absolute temperature T (L∝ (1 / T)), in the case of ceramics, the equation (3) can be expressed by the following equation (4) (where A is a proportional constant): As shown, the thermal conductivity tends to decrease with increasing temperature.

  λ∝C ・ L ・ v (3)

  λ = A · (C · L · v) / T (4)

_Nd listed in Table _{2 2 Ti 2 O 7, La} 2 Si 2 O 7, La 2 Ti 2 O 7, Sr 2 Nb 2 O 7, Sr 2 Ta 2 O 7, Sr 3 Ti 2 O 7, La 2 NiO The thermal conductivity of ₄ is a value measured at room temperature (~ 300K). According to equation (4), it can be estimated that the thermal conductivity of these materials at 1000 ° C. (1273 K) is about ¼ of the value at room temperature. The estimated thermal conductivity values at 1000 ° C. are shown in Table 3.
As shown in Table 3, it can be estimated that the thermal conductivity of these materials at 1000 ° C. is smaller than that of zirconia, which is considered suitable as a thermal barrier coating material.

[Example 7]
In this example, it was considered to combine the materials whose thermal expansion coefficient and thermal conductivity were measured in Example 6 above.
According to Example 6, La ₂ Si ₂ O ₇ , La ₂ Ti ₂ O ₇ , Sr ₂ Ta ₂ O _7, and LaTaO ₄ have a thermal expansion coefficient smaller than that of zirconia as it is, and therefore, as a thermal barrier coating material. If used, tensile stress may occur. Therefore, in order to increase the coefficient of thermal expansion while maintaining the low thermal conductivity of these materials, a combination with other materials having a high coefficient of thermal expansion listed in Table 1 was examined.

When two types of ceramics having a large difference in thermal expansion coefficient are combined, the thermal expansion coefficient (α _c ) of the composite material is expressed by the following equation (5) called the Turner equation. In the equation (5), α is a coefficient of thermal expansion, K is a bulk modulus, V is a volume fraction, a subscript m is a matrix, and a subscript p is a phase to be added.

_{α c = (α p V p} K p + α m V m K m) / (V p K p + V m K m) ··· (5)

The thermal conductivity (λ _c ) of the composite material is expressed by the following equation (6) when the equation (2) is substituted into the above equation (1). In the equation (6), λ is the thermal conductivity, V is the volume fraction, the subscript m is the matrix, and the subscript p is the phase to be added.

_{λ c = λ m {1 +} 2V p (1-λ m / λ p) / (2λ m / λ p +1)} / {1-V p (1-λ m / λ p) / (2λ m / λ p +1 )} (6)

For example, a low thermal expansion (low thermal conductivity) material LaTaO ₄ (α = 5.33, λ = 2.11) shown in Tables 1 and 2 is used as a high thermal expansion (high thermal conductivity) material, Sr ₃ Ti _2. It is assumed that O ₇ (α = 1.11.99, λ = 5.64) is combined. That is, Sr ₃ Ti ₂ O ₇ is a matrix and LaTaO ₄ is added. If LaTaO ₄ is added at 10 vol%, V _p = 0.1, and the bulk modulus of Sr ₃ Ti ₂ O ₇ and LaTaO ₄ is K _m = 146.7 and K _p = 213.6, respectively.
Substituting these numerical values into equations (5) and (6),
From equation (5), α _c = 11.06
From equation (6) λ _c = 5.11
It becomes. Since λ _c = 5.11 is room temperature thermal conductivity, assuming that the thermal conductivity at 1000 ° C. is about ¼, λ = 1.28. This is an advantageous value as a thermal barrier coating compared with those of the current zirconia-based materials in terms of thermal expansion coefficient and thermal conductivity.

It can be seen that by combining the two kinds of materials in this manner, both the thermal expansion coefficient and the thermal conductivity can be taken, and the values can be controlled by appropriately determining the volume fraction. And here, the case where Sr ₃ Ti ₂ O ₇ and LaTaO ₄ are combined was calculated as an example, but the thermal expansion coefficient and the thermal conductivity were determined by conducting the same examination for other materials listed in the table. It can be easily estimated that it can be controlled.
Therefore, a material obtained by combining two or more materials listed in Tables 1 and 2 is considered to be sufficiently suitable as a thermal barrier coating material.

[Example 8]
Mg ₂ SiO ₄ has been used in electric and electronic devices such as IC substrates and packaging as insulating material, have been examples are not used in high temperature structural materials including a thermal barrier coating. The present inventors have focused on the high thermal expansion and low thermal conductivity with the Mg ₂ SiO _4, consider the application to the thermal barrier coating was investigated first Mg ₂ SiO ₄ and analogs thereof.

Mg ₂ SiO ₄ is called the mineral name Forsterite, and belongs to a material having an olivine structure of M ₂ SiO ₄ (M is a divalent metal element) classified by orthorhombic and space group Pmnb. Other materials having such an orthorhombic and olivine structure classified by the space group Pmnb include Fe ₂ SiO ₄ (mineral name Fayalite), Mn ₂ SiO ₄ (mineral name Tephroite), Ni ₂ SiO ₄ ( Mineral name Liebenbergite), Co ₂ SiO _{4 and the} like.

The divalent metal element represented by M in the above composition formula does not have to be one kind in particular, and is in the form of (M, M ′) ₂ SiO ₄ , for example, (Fe, Mg) ₂ SiO ₄ (mineral name Olivine ), (Ca, Mg) ₂ SiO ₄ (mineral name Monticellite), (Fe, Mn) ₂ SiO ₄ (mineral name Knebelite), (Ca, Mn) ₂ SiO ₄ (mineral name Glaucochroite), (Ca, Fe) ₂ Materials such as SiO ₄ (mineral name Kirschsteinite) also exist. As shown in the form of (M, M ′) ₂ , this divalent metal element portion does not necessarily have a 1: 1 ratio of M and M ′, and can take an arbitrary ratio. it can.

These materials represented by M ₂ SiO ₄ or (M, M ′) ₂ SiO ₄ were examined for thermal stability. The state diagrams of each material are shown in FIGS. Table 4 shows melting points (or decomposition temperatures) that can be read from the respective phase diagrams. The sources of the state diagrams in FIGS. 2 to 11 are listed in Table 9.

Of these, Fe ₂ SiO ₄ , Mn ₂ SiO ₄ , (Fe, Mn) ₂ SiO ₄ , CaMnSiO ₄ , and CaFeSiO ₄ having a melting point lower than 1400 ° C. are clearly not considered. Is appropriate. However, as can be seen, for example, in the case of (Fe, Mg) ₂ SiO _4, a composite having a high melting point Mg ₂ SiO ₄ and a low melting point Fe ₂ SiO ₄ has an intermediate melting point (Fe, Mg). ) ₂ SiO ₄ can be made. The fact that the melting point can be controlled by the ratio of Fe and Mg can be read from the FeO-MgO-SiO ₂ phase diagram of FIG. Therefore, it is easily estimated that a material having a desired melting point can be obtained by the combination of M and M ′ elements in (M, M ′) ₂ SiO ₄ and the ratio thereof other than the case of Fe and Mg. it can.

Therefore, the composition formulas Mg ₂ SiO ₄ , Ni ₂ SiO ₄ , Co ₂ SiO ₄ , (Ca, Mg) ₂ SiO ₄ , (Mg, Co) ₂ SiO ₄ , (Mg, Ni) ₂ SiO ₄ , (Ni, Co ) About the composition represented by ₂ SiO ₄ , the oxide powder of each constituent element is weighed so as to have a predetermined ratio, solid phase mixed using a ball mill, dried, and calcined at 1200 ° C. Thus, calcined powder was produced. When these calcined powders were identified by powder X-ray diffraction, it was confirmed that no unreacted raw material components such as SiO ₂ remained and that all samples were in a single phase.

Table 5 shows the theoretical density of the materials listed in Table 4. However, those materials whose melting point is lower than 1400 ° C. and are inappropriate for use as a thermal barrier coating are omitted. Further, Mg ₂ SiO ₄ , Ni ₂ SiO ₄ , Co ₂ SiO ₄ , (Ca, Mg) ₂ SiO ₄ , (Mg, Co) ₂ SiO ₄ , (Mg, Ni) ₂ SiO ₄ , (Ni, Table 5 also shows the results of calcining each calcined powder of Co) ₂ SiO ₄ at 1400 ° C. and measuring the density of the sintered body. Of these, Co ₂ SiO ₄ was excluded from the measurement because a part of the sintered body was melted. Further, the density value of 3YSZ (3 mol% Y ₂ O ₃ —ZrO ₂ : yttria partially stabilized zirconia) as a comparative material is also shown in the table.

The relative density of 3YSZ presented as a comparative material was about 97%, and the other materials showed a low relative density of 75 to 94%, compared to almost a dense body. This can be presumed that M ₂ SiO ₄ and (MM ′) ₂ SiO ₄ -based materials are generally difficult to sinter as compared to zirconia. When sprayed onto a metal part as a thermal barrier coating, the structure is in a state having a large number of pores as shown in FIG. And since the heat insulation performance of the material can be maintained due to the presence of such a large number of pores, these olivine structures of M ₂ SiO ₄ and (MM ′) ₂ SiO _{4 which} are considered to be less dense than the current zirconia. It is considered that a material having a thickness is suitable as a thermal barrier coating.

  In addition, since the theoretical density of each material is about 1/2 to 5/6 that of zirconia, the weight can be reduced when it is applied as a thermal barrier coating, which has a positive effect on the efficiency of gas turbines and the like. Since such a material can be expected, it is considered that these materials are practically suitable in this respect.

[Example 9]
Next, the composition formula Mg ₂ SiO ₄ , Ni ₂ SiO ₄ , (Ca, Mg) ₂ SiO ₄ , (Mg, Co) ₂ SiO ₄ , (Mg, Ni) ₂ SiO ₄ , (Ni, Co) ₂ SiO ₄ A 4 × 4 × 15 mm rod-shaped sample was cut out from each of the obtained sintered bodies and the coefficient of thermal expansion was measured. Table 6 shows the values of the coefficient of thermal expansion at 1000 ° C. In addition, the value of the thermal expansion coefficient of 3YSZ was also described in the table as a comparative material.

As shown in Table 6, the thermal expansion coefficient of any of the prepared samples is larger than that of 3YSZ. This suggests that when used as a thermal barrier coating, there is less potential for tensile stress with the underlying metal part than with current zirconia. Therefore, it is considered that the material having the olivine structure of M ₂ SiO ₄ and (MM ′) ₂ SiO ₄ is also suitable as a thermal barrier coating in this respect.

Next, a composition represented by the composition formula Mg ₂ SiO ₄ , Ni ₂ SiO ₄ , (Ca, Mg) ₂ SiO ₄ , (Mg, Co) ₂ SiO ₄ is produced by firing at 1400 ° C. A disk-shaped sample having a diameter of 10 mmφ and a thickness of 1 mm was cut out from each sintered body, and the thermal conductivity was measured by a laser flash method. Table 7 shows the values of thermal conductivity at room temperature. In addition, the value (1000 degreeC, literature value) of the thermal conductivity of 3YSZ was also described in the table | surface as a comparative material.

When the same consideration as described in Example 6 is performed, Mg ₂ SiO ₄ , Ni ₂ SiO ₄ , (Ca, Mg) ₂ SiO ₄ , and (Mg, Co) ₂ SiO listed in Table 7 are obtained. _It can be estimated that the thermal conductivity at 1000 ° C. (1273 K) is about ¼ of the value at room temperature with respect to the thermal conductivity value measured at room temperature (˜300 K) of 4. Table 8 shows the estimated thermal conductivity values at 1000 ° C.

  As shown in Table 8, it can be estimated that the thermal conductivity of these materials at 1000 ° C. is smaller than that of zirconia, which is considered to be sufficiently suitable as a thermal barrier coating.

[Example 10]
In this example, in Example 6 described above, it can be estimated that the thermal expansion coefficient is larger than that of zirconia and the thermal conductivity is smaller than that of zirconia, so that it is suitable as a thermal barrier coating material. Based on Sr ₂ Nb ₂ O ₇ , the thermal expansion coefficient α and the thermal conductivity λ were similarly examined for other oxides containing Nb. Similarly, based on La ₂ NiO ₄ described in Example 6, another rare earth element instead of La, for example, an oxide obtained by substituting a trivalent rare earth element like La, such as Pr, Nd, and Eu, Based on LaTaO ₄ described in Example 6, instead of La, other trivalent metal elements such as Al, V, Cr, Fe, Ga, Y, Rh, In, Ce, Nd, Sm, Eu, Gd , Dy, Ho, Er, Tm, Yb, Lu and other oxides containing Ta were similarly examined for thermal expansion coefficient α and thermal conductivity λ. The materials selected here are Sr ₄ Nb ₂ O ₉ , Sr ₅ Nb ₄ O ₁₅ , and Ca ₂ Nb ₂ O ₇ using Ca, which is the same alkaline earth metal system, instead of Sr ₄ Nb ₂ O ₉ , Sr ₅ , and Sr. , Oxides containing Nb such as YNbO ₄ and LaNbO ₄ using rare earth elements instead of Sr, Nd ₂ NiO ₄ substituted with Nd instead of La in La ₂ NiO ₄ , Nd instead of La in LaTaO ₄ NdTaO ₄ , Ca ₄ Ta ₂ O ₉ and BaTa ₂ O ₆ substituted with These materials are shown in Table 10.

As shown in Table 10, these materials all have a melting point of 1400 ° C. or higher, and it is considered that there is no problem in thermal stability in a temperature range that can be used as a thermal barrier coating.
In synthesizing the materials listed in Table 10, oxides, hydroxides or carbonates of the respective constituent elements were selected as starting materials, weighed so as to have a predetermined ratio, and solid-phase mixed using a ball mill. After drying the mixed powder, it was calcined at 1400 ° C. When the obtained calcined powder was identified by powder X-ray diffraction, it was confirmed that no unreacted raw material component remained and that all samples were in a single phase. Subsequently, each said sample was baked at 1500 degreeC, the rod-shaped sample of 4x4x15mm was cut out from the sintered compact, and the thermal expansion coefficient was measured. Table 11 shows the values of the coefficient of thermal expansion at 1000 ° C. As a comparative material, the thermal expansion coefficient of 3YSZ is also shown in the table.

Among the prepared samples, Sr ₄ Nb ₂ O ₉ , Sr ₅ Nb ₄ O ₁₅ , Ca ₂ Nb ₂ O ₇ , and LaNbO ₄ have values of thermal expansion higher than that of 3YSZ. This suggests that when these materials are used as thermal barrier coatings, they are less likely to generate tensile stress with the underlying metal part than with the current zirconia. YNbO ₄ also has almost the same thermal expansion coefficient as that of zirconia, but when used as a thermal barrier coating, the tensile stress generated between the base metal parts is the same as that of zirconia. It can be estimated that it is the same level as when used, and there is no problem in terms of thermal expansion as a thermal barrier coating material.

In this example, the coefficient of thermal expansion was measured only for the nine types of samples listed in Table 11. However, oxidation in which rare earth elements other than Nd, such as Pr and Eu, were substituted for La in La ₂ NiO ₄ . Or trivalent metal elements other than Nd instead of La in LaTaO ₄ , such as Al, V, Cr, Fe, Ga, Y, Rh, In, Ce, Sm, Eu, Gd, Dy, Ho, Er, Even if oxides substituted for Tm, Yb, and Lu have the same crystal structure as Nd ₂ NiO ₄ and NdTaO ₄ , it is easy to guess that they will have similar thermal expansion coefficients. it can.

Next, Sr ₄ Nb ₂ O ₉ , Ca ₂ Nb ₂ O ₇ , YNbO ₄ , Nd ₂ NiO ₄ , NdTaO ₄ , Ca ₄ Ta ₂ O ₉ , and BaTa ₂ O ₆ were fired at 1500 ° C. and sintered. A disk-shaped sample having a diameter of 10 mmφ and a thickness of 1 mm was cut out from the body, and the thermal conductivity was measured by a laser flash method. Table 12 shows the values of thermal conductivity at room temperature. In addition, the value (1000 degreeC, literature value) of the thermal conductivity of 3YSZ was also described in the table | surface as a comparative material.

  When the same consideration as described in Example 6 is performed and the thermal conductivity at 1000 ° C. (1273 K) is estimated by the above-described formula (4), it is as shown in Table 13.

As shown in Table 13, it can be estimated that the thermal conductivity of these materials at 1000 ° C. is smaller than that of zirconia, which is considered suitable as a thermal barrier coating material.
Moreover, since it is possible to control a thermal expansion coefficient and a thermal conductivity by using Formula (5) and (6) demonstrated in Example 7, two types of materials listed in Table 11 and 12 or It is considered that a material obtained by further compounding is sufficiently suitable as a thermal barrier coating material. Similarly, a material obtained by combining two or more of the materials listed in Tables 1 and 2 in Example 6 and the materials listed in Tables 11 and 12 in this example is also suitable as a thermal barrier coating material. It is thought that.

In this example, the thermal conductivity was measured only for the seven types of samples listed in Table 12. However, in La ₂ NiO ₄ , oxidation was performed by substituting rare earth elements other than Nd, for example, Pr and Eu, instead of La. Or trivalent metal elements other than Nd instead of La in LaTaO ₄ , such as Al, V, Cr, Fe, Ga, Y, Rh, In, Ce, Sm, Eu, Gd, Dy, Ho, Er, It is easy to guess that even oxides substituted for Tm, Yb, and Lu will have the same crystal structure as Nd ₂ NiO ₄ and NdTaO ₄ and will have the same thermal conductivity. it can.

[Example 11]
In this example, in Example 6 described above, it can be estimated that the thermal expansion coefficient is larger than that of zirconia and the thermal conductivity is smaller than that of zirconia, so that it is suitable as a thermal barrier coating material. Based on the solid solution of the Sr—Nb-based oxide, the thermal expansion coefficient α and the thermal conductivity λ of the solid solution of BaTa ₂ O ₆ , the solid solution of LaNiO ₄ and other similar compounds were similarly examined. The materials selected here are Ca ₄ Nb ₂ O ₉ , Ca ₁₁ Nb ₄ O ₂₁ , BaTa _1.8 Ti _0.2 O ₆ , BaTa _1.8 Zr _0.2 O ₆ , Sr ₂ Nb _1.8 Ti _{0. .2} O ₇ , Sr ₂ Nb _{2 -x} Zr _x O ₇ , Sr ₄ Nb _{2 -x} Ti _x O ₉ , Sr ₄ Nb _1.8 Zr _0.2 O ₉ , La ₃ NbO ₇ , DyNbO ₄ , La _{1 .8} Ca _0.2 NiO ₄ , La ₆ WO ₁₂ , Ce ₆ WO ₁₂ , Dy ₆ WO ₁₂ , Sm ₆ WO ₁₂ , Yb ₆ WO ₁₂ , Y ₆ WO ₁₂ , Dy ₂ WO ₆ , Yb ₂ WO ₆ SrYb ₂ O _{4, La} 6 _WO 12, was a _Dy 2 WO _6. These materials are shown in Table 14.

  As shown in Table 14, all of these materials have a melting point of 1700 ° C. or higher, and some of them have a melting point of 2500 ° C., which is higher than that of zirconia in which yttria is dissolved, and can be used as a thermal barrier coating. It is considered that there is no problem with thermal stability in a wide temperature range.

Next, the materials listed in Table 15 were synthesized. In synthesizing these materials, oxides, hydroxides or carbonates of respective constituent elements were selected as starting materials, weighed so as to have a predetermined ratio, and solid phase mixed using a ball mill. After drying the mixed powder, it was calcined at 1400 ° C. When the obtained calcined powder was identified by powder X-ray diffraction, it was confirmed that no unreacted raw material components remained and that all the samples were in a single phase. Each peak was examined in detail, and a peak shift was observed in a certain direction, and it was confirmed that the added solid solution component was surely dissolved in the crystal. Subsequently, each said sample was baked at 1500 degreeC, the rod-shaped sample of 4x4x15mm was cut out from the sintered compact, and the thermal expansion coefficient was measured. In general, even if the compound has a similar compound or a similar crystal structure, the thermal conductivity often varies greatly due to subtle differences, but the thermal expansion coefficient rarely varies so much. That is, for Ca ₄ Nb ₂ O ₉ and Ca ₁₁ Nb ₄ O ₂₁ , Ca ₂ Nb ₂ O ₇ and BaTa _{2 -x} Ti _x O ₆ , BaTa _{2 -x} Zr _x O ₆ and BaTa ₂ O ₆ Sr ₂ Nb _{2 -x} Ti _x O ₇ , Sr ₂ Nb _{2 -x} Zr _x O ₇ for Sr ₂ Nb ₂ O ₇ , Sr ₄ Nb _{2 -x} Ti _x O ₉ , Sr ₄ Nb _{2 -x} Zr and _Sr 4 _Nb 2 _{O 9} for _x O _9, and Lanbo ₄ for La ₃ NbO 7, DyNbO _4, and LaNiO ₄ for _{La 2-x Ca x NiO 4} , Ce 6 WO 12, Dy 6 WO 12, It is clear that Sm ₆ WO ₁₂ , Yb ₆ WO ₁₂ , Y ₆ WO ₁₂ have La ₆ WO ₁₂ and Yb ₂ WO ₆ have the same thermal expansion coefficient as Dy ₂ WO ₆ . Therefore, it is omitted here, and Table 15 shows the thermal expansion coefficient values of SrYb ₂ O ₄ , La ₆ WO ₁₂ , and Dy ₂ WO ₆ at 1000 ° C. As a comparative material, the thermal expansion coefficient of 3YSZ is also shown in the table.

As shown in Table 15, among the prepared samples, SrYb ₂ O ₄ , La ₆ WO ₁₂ , and Dy ₂ WO ₆ have a coefficient of thermal expansion larger than that of 3YSZ. This suggests that, when these materials are used as a thermal barrier coating, the possibility of generating a tensile stress with the underlying metal part (base material) is smaller than that of the current zirconia.

Next, Ca ₄ Nb ₂ O ₉ , Ca ₁₁ Nb ₄ O ₂₁ , BaTa _1.8 Ti _0.2 O ₆ , BaTa _1.8 Zr _0.2 O ₆ , Sr ₂ Nb _1.8 Ti _0.2 O ₇ , Sr ₂ Nb _2−x Zr _x O ₇ , Sr ₄ Nb _2−x Ti _x O ₉ , Sr ₄ Nb _1.8 Zr _0.2 O ₉ , La ₃ NbO ₇ , DyNbO ₄ , La _1.8 Ca _0.2 NiO ₄ , La ₆ WO ₁₂ , Ce ₆ WO ₁₂ , Dy ₆ WO ₁₂ , Sm ₆ WO ₁₂ , Yb ₆ WO ₁₂ , Y ₆ WO ₁₂ , Dy ₂ WO ₆ , Yb ₂ WO ₆ at 1400 ° C. After firing, a disk-shaped sample having a diameter of 10 mmφ and a thickness of 1 mm was cut out from the sintered body, and the thermal conductivity was measured by a laser flash method. Table 16 shows the values of thermal conductivity at room temperature. In addition, the value (1000 degreeC, literature value) of the thermal conductivity of 3YSZ was also described in the table | surface as a comparative material.

  From the results obtained above, the same considerations as those described in Example 6 were made, and the thermal conductivity at 1000 ° C. (1273 K) was estimated by the equation (4) shown above, as shown in Table 17. Become.

As shown in Tables 16 and 17, the thermal conductivity of these materials at room temperature and 1000 ° C. can be estimated to be smaller than that of zirconia, and is considered suitable as a thermal barrier coating material.
Moreover, since it is possible to control a thermal expansion coefficient and a thermal conductivity by using the formulas (5) and (6) described in Example 7, two types of materials listed in Table 15 and Table 16 are used. Alternatively, a composite material more than that is considered to be sufficiently suitable as a thermal barrier coating material. Similarly, a material obtained by combining two or more of the materials listed in Tables 1 and 2 in Example 6 and the materials listed in Tables 15 and 16 in this example is also sufficient as a thermal barrier coating material. It is considered suitable.

In this example, the thermal conductivity was measured only for 19 types of samples listed in Table 16, but other rare earth elements such as Pr and Nd were used instead of La in La ₆ WO ₁₂ and Dy ₂ WO ₆ . Even oxides substituted with Eu, Gd, Er, etc. will have the same crystal structure as La ₆ WO ₁₂ and Dy ₂ WO ₆ and will have similar thermal conductivity Can be easily guessed.

[Example 12]
In this example, in Example 6 above, the material estimated to have a thermal expansion coefficient larger than that of zirconia and a thermal conductivity smaller than that of zirconia is suitable as a thermal barrier coating material. A verification test was conducted. For the verification, assuming the operating condition of the gas turbine as the application destination, considering the thermal stress applied at the time of start / stop as the state where the greatest stress is applied, a thermal cycle test was conducted in which the fatigue phenomenon due to this thermal stress was investigated elementally. Carried out.

First, a Ni-based heat-resistant alloy having a composition Ni-16Cr-8.5Co-1.7Mo-2.6W-1.7T-0.9Nb-3.4Al-3.4Ti (at%) was cut out into a disk shape. A test piece substrate was obtained. And after grit blasting with the substrate surface _Al 2 _{O 3} powder, the bond coat layer composed of Co-32Ni-21Cr-8Al- 0.5Y (at%) made CoNiCrAlY alloy having a composition as a metal bonding layer thereon Tested by forming a thermal barrier coating film by laminating a ceramic layer (a coating composed of thermal barrier coating material) on this CoNiCrAlY alloy bond coat layer by an atmospheric pressure plasma spray method. It was a piece.
In addition, the thickness of the bond coat layer (CoNiCrAlY alloy film) was 0.1 mm, and the thickness of the ceramic layer was 0.5 mm.

Next, a large infrared lamp is condensed on the surface of the thermal barrier coating film side of this test piece and heated, and when the surface temperature is heated to a predetermined temperature, the lamp light is blocked by the shutter. Then, a heat cycle test was repeated in which a heating / cooling cycle in which the shutter was opened again and heated when it was cooled to a predetermined temperature was repeated.
Further, in order to finish the test in a short cycle, cooling air of about −20 ° C. was jetted from the nozzle to the opposite surface of the test piece to be heated as an acceleration condition to cool the entire test piece. As a result, the test piece is cooled to approximately 0 ° C. with the surface on the side opposite to the thermal barrier coating film as the center, so the entire surface is always cooled except for the surface on the thermal barrier coating film side when heated by the infrared lamp. Become so. And by giving such a temperature difference intentionally, a very big thermal stress centering on a film | membrane interface is loaded to a test piece. This test was performed until peeling of the thermal barrier coating surface was confirmed visually.

The thermal cycle test was performed on a sample coated with a thermal barrier coating film made of Sr ₂ Nb ₂ O ₇ . As conditions for the thermal cycle test, the maximum temperature of the test piece heating surface (thermal barrier coating film surface) is set to 1450 ° C., and the maximum interface temperature (maximum temperature at the interface between the thermal barrier coating film and the substrate) is repeated to 850 ° C. Was heated. At that time, the heating time was 1 minute and the cooling time was 1 minute. The results of this thermal cycle test are shown in Table 18. For comparison, the case of 3YSZ thermal barrier coating film is also shown.

As is clear from Table 18, it was confirmed that Sr ₂ Nb ₂ O ₇ has an excellent effect as a thermal barrier coating material. This is considered to be the result of this material having a higher coefficient of thermal expansion and lower thermal conductivity than the comparative material, and it can be easily assumed that the same effect will be observed for other materials. .

[Example 13]
Refractive index of Sr ₄ Nb ₂ O ₉ , Sr ₂ Nb ₂ O ₉ , YSZ, La ₂ Zr ₂ O ₇ , LaTaO ₄ , LaNiO ₄ , MgCoSiO ₄ , CaMgSiO ₄ and Mg ₂ SiO ₄ at a wavelength of 600 nm. The relationship between the reciprocal of and the measured value of thermal conductivity was investigated. A graph plotting the results is shown in FIG. From this result, the relationship between the reciprocal of the refractive index (x) and the thermal conductivity (y) is approximated by the least square method.
y = 27.328x-11.222
Met. The straight line represented by this formula is shown in the graph of FIG.
From this result, it can be inferred that the higher the refractive index, the lower the thermal conductivity and the better the thermal barrier coating material.

[Example 14]
Dielectric constant of Sr ₄ Nb ₂ O ₉ , Sr ₂ Nb ₂ O ₉ , YSZ, La ₂ Zr ₂ O ₇ , LaTaO ₄ , LaNiO ₄ , MgCoSiO ₄ , CaMgSiO ₄ and Mg ₂ SiO ₄ at a frequency of 1 MHz. The relationship between the reciprocal of and the measured value of thermal conductivity was investigated. A graph plotting the results is shown in FIG. Further, from this result, when the relationship between the reciprocal of the dielectric constant (x) and the thermal conductivity (y) is approximated by the least square method,
y = 55.783x-0.6328
Met. The straight line represented by this formula is shown in the graph of FIG.
From this result, it can be inferred that a material having a higher dielectric constant has a lower thermal conductivity and is superior as a thermal barrier coating material.

[Example 15]
The dielectrics having a refractive index of 2.2 or more at 25 ° C. and a wavelength of 600 nm that can be suitably used for the thermal barrier coating material of the present invention are listed below. The respective refractive indices at 25 ° C. and a wavelength of 600 nm are also shown on the right side of the composition formula of each dielectric.
Mn _0.91 Zn _0.09 Fe ₂ O ₄ 4.65
YBa ₂ Cu ₃ O _(x) 4.5
YMnO ₃ 4.5
La ₂ CuO ₄ 2.86
CuFe ₂ O ₄ 2.71
Bi ₁₂ TiO ₂₀ 2.682
Bi ₁₂ GeO ₂₀ 2.67214
Bi ₂ MoO ₆ 2.67
Bi ₁₂ TiO ₂₀ 2.65
Sb _0.8 Bi _0.2 NbO ₄ 2.61

Sb _0.9 Bi _0.1 NbO ₄ 2.61
Sb _0.7 Bi _0.3 NbO ₄ 2.61
MnBO ₃ 2.6
CaFe ₂ O ₄ 2.58
SbNbO ₄ 2.58
(Fe, Mn) (Ta, Nb) ₂ O ₆ 2.53
(Fe, Mn) (Nb, Ta) ₂ O ₆ 2.53
Sn {(Ta, Nb) ₂ O ₇ } 2.52
Fe ₆ Ti ₅ Sb ₂ O ₂₁ 2.51
Bi ₄ Ti ₃ O ₁₂ 2.5

Bi ₂ WO ₆ 2.5
BiVO ₄ 2.5
Sr _0.61 Ba _0.39 (Nb ₂ O ₆ ) 2.4973
Ba ₃ LaNb ₃ O ₁₂ 2.487
MnTiO ₃ 2.481
In ₃ Sb ₅ O ₁₂ 2.48
Sb (Ta, Nb) O ₄ 2.48
In ₃ Sb ₅ O ₁₂ 2.48
Bi ₁₂ ZnO ₁₉ 2.48
SbTaO ₄ 2.452

Nd ₂ CuO ₄ 2.45
BiNbO ₄ 2.45
FeNb ₂ O ₆ 2.45
BiNbO ₄ 2.45
MnWO ₄ 2.43
Bi (Ta, Nb) O ₄ 2.428
DyVO ₄ 2.422
BiVO ₄ 2.41
Fe ₂ TiO ₅ 2.4075
MnNb ₂ O ₆ 2.4

(TmBiY) ₃ (FeGa) ₅ O ₁₂ 2.4
FeWO ₄ 2.4
(Mg, Fe, Mn) (Nb, Ti, Ta) ₂ O ₆ 2.4
FeNb ₂ O ₆ 2.4
NiFe ₂ O ₄ 2.39
Bi ₂ (CO ₃ ) O ₂ 2.39
Bi ₂ SrTa ₂ O ₉ 2.38
Fe ₂ TiO ₅ 2.375
(Mn, Sb, Ca) ₄ (Mn, Fe, Mg) ₃ {O ₈ SiO ₄ } 2.36
Ba _0.67 Sr _0.33 Nb ₂ O ₆ 2.357

Sr _0.75 Ba _0.25 Nb ₂ O ₆ 2.356
Sr _0.46 Ba _0.54 Nb ₂ O ₆ 2.355
La ₂ Ti ₂ O ₇ 2.35
BiTaO ₄ 2.35
Zr ₃ Nb ₂ O ₁₁ 2.35
MgFe ₂ O ₄ 2.34
ZnMn ₂ O ₄ 2.34
MnTa ₂ O ₆ 2.34
UV ₄ O ₁₀ 2.34
O ₇ Pr ₂ Ti ₂ 2.34

Fe ₂ Sb ₂ O ₇ 2.33
ZrNb ₆ O ₁₇ 2.325
YVO ₄ 2.3175
(Ba, Sr) Nb ₂ O ₆ 2.317
ZnFe ₂ O ₄ 2.31
FeWO ₄ 2.31
MgTiO ₃ 2.31
TiNb ₂ O ₇ 2.305
(U, Ca, Y, Ce) (Ti, Fe) ₂ O ₆ 2.3
(Ga ₂ S ₃ ) _0.69 (La ₂ O ₂ S) _0.31 2.3

MgNb ₂ O ₆ 2.29
Cr ₂ NiO ₄ 2.29
LaTiNbO ₆ 2.29
Ca ₂ Fe ₂ O ₅ 2.29
Ca ₂ Cr ₂ O ₅ 2.29
AlNb ₂₅ O ₆₄ 2.28
MgCa ₂ Fe ₂ O ₆ 2.28
Mn (Ta, Nb, Sn) ₂ O ₆ 2.28
YNbO ₄ 2.28
La ₅ Ti ₂ NbO ₁₄ 2.28

Nd ₂ Ti ₂ O ₇ 2.27
Yb ₃ Sb ₅ O ₁₂ 2.27
PtO ₂ 2.26
Tb ₃ Sb ₅ O ₁₂ 2.26
DyVO ₄ 2.257
YbVO ₄ 2.256
ErVO ₄ 2.254
VNb ₂ O ₇ 2.25
BaZr _0.25 Nb _1.5 O _5.25 2.25
(Y, Ce, Fe, U, Ca) (Nb, Ta, Fe) ₂ O ₆ 2.25

Yb ₂ Ti ₂ O ₇ 2.25
GdVO ₄ 2.244
(Bi, Lu, Nd) ₃ (Fe, Al) ₅ O ₁₂ 2.2403
BaNb ₂ O ₆ 2.24
NbTiYO ₆ 2.24
Ca ₃ Ti ₂ O ₇ 2.24
Pr ₃ Sb ₅ O ₁₂ 2.22
AlNb ₁₁ O ₂₉ 2.22
Sm ₂ Ti ₂ O ₇ 2.22
BiOF 2.213

Y _2.875 Nd _0.125 Fe ₅ O ₁₂ 2.211
LaNbO ₄ 2.21
(ZrO ₂ ) _0.915 (Sm ₂ O ₃ ) _0.085 2.21
(ZrO ₂ ) _0.915 (Dy ₂ O ₃ ) _0.085 2.21
Y ₃ Fe ₅ O ₁₂ 2.2
Ca ₃ Nb ₂ O ₈ 2.2
LaTiNbO ₆ 2.2
MnWO ₄ 2.2
(Ta, Nb, Sn, Mn, Fe) ₂ O ₄ 2.2
In ₂ Sn ₂ O _(7-x) 2.2
Ba _0.75 Sr _0.25 TiO ₃ 2.2

[Example 16]
The dielectrics having a dielectric constant of 35 or more at 25 ° C. and a frequency of 1 MHz that can be suitably used for the thermal barrier coating material of the present invention are listed below. The dielectric constants at 25 ° C. and the wavelength of 1 MHz are also shown on the right side of the composition formula of each dielectric.
Bi ₃ TiNbO ₉ 312.949887179
SrBi ₂ Nb ₂ O ₉ 312.948787179
Sr _0.6 Ba _0.4 Nb ₂ O ₆ 293.1794872
Ba _0.75 Y _0.16 Nb ₂ O ₆ 286.5897436
Bi ₂ CuO ₄ 286.5897436
Bi ₇ Ti ₃ Fe ₃ O ₂₁ 284.28333333
SbNbO ₄ 280
Sr ₂ CaTiNb ₄ O ₁₅ 280
(SrB ₄ O ₇ ) _0.5 (Bi ₂ VO _5.5 ) _0.5 279.6705128
Sr _0.5 Ba _0.5 Nb ₂ O ₆ 278.0230769

BaBi ₂ Nb ₂ O ₉ 2700.1153546
BaTi _0.90 Sn _0.04 Si _0.06 O ₃ 2700.115384
Ba _0.7 Sm _0.2 Nb ₂ O ₆ 256.9935974
Ba _0.90 La _0.10 Ti _0.975 O ₃ 253.6410256
Ba ₃ Bi ₂ MoO ₉ 253.6410256
Sr ₆ Ti ₂ Nb ₈ O ₃₀ 248.69887179
MnTa ₂ O ₆ 237.1666667
Ba _0.8 Y _0.13 Nb ₂ O ₆ 233.87717949
(SrB ₄ O ₇ ) _0.5 (Bi ₂ VO _5.5 ) _0.5 231.565353846
Sr _0.90 La _0.10 Ti _0.90 Co _0.10 O ₃ 227.2820513

Ba _0.7 Zr _0.4 Nb _0.7 O ₃ 222.0102564
Ba ₂ YCu ₃ O _(x) 220.6923077
BiCu ₃ Ti ₃ FeO ₁₂ 218.05643
Ba ₅ DyTi ₃ Nb ₇ O ₃₀ 196.3102564
(BiFeO ₃ ) _0.8 (BaTiO ₃ ) _0.2 194.3333333
Ba ₅ SmTi ₃ Nb ₇ O ₃₀ 192.6858974
(Ba, Sr) Nb ₂ O ₆ 191.0384615
Ba _0.70 Y _0.20 Nb ₂ O ₆ 191.0384615
Ba _0.85 Sm _0.10 Nb ₂ O ₆ 191.0384615
Ni _0.4 Zn _0.6 Fe ₂ O ₄ 191.0384615

Ba _0.6 Sm _0.267 Nb ₂ O ₆ 187.7435897
Ba ₂ CaTiNb ₄ O ₁₅ 187.7435897
ZnCo _0.5 Cr _0.5 MnO ₄ 184.4487179
Ca _0.90 Y _0.10 Ti _0.90 Co _0.10 O ₃ 177.2
Ba ₃ TiNb ₄ O ₁₅ 171.2692308
Ba _0.65 Zr _0.3 Nb _0.75 O ₃ 163.3615385
Ca _0.97 Y _0.03 Ti _0.97 Co _0.03 O ₃ 161.0551282
Ba _0.8 La _0.132 Nb ₂ O ₆ 158.0987436
Ba ₃ MgTa ₂ O ₉ 154.7948718
In ₂ Ca ₈ Cu ₄ O ₁₅ 153.147474359

Ba _0.6 Sr _0.4 TiO ₃ 144.9102564
ZnMnCrO ₄ 143.2628205
Zn _0.3 Mg _0.9 Ti _0.2 Fe _1.6 O ₄ 141.9494718
Ba _0.25 Sr _0.75 Nb ₂ O ₆ 141.6153846
In ₁₄ Ca ₉ Cu ₂ O ₃₂ 141.6153846
BaBi ₂ Ta ₂ O ₉ 138.3205128
Sr _0.75 Ba _0.25 Nb ₂ O ₆ 138.3205128
BaSn ₂ Fe ₄ O ₁₁ 135.0256641
Ba _0.67 Sr _0.33 Nb ₂ O ₆ 134.36666667
ZnCo _0.4 Cr _0.6 MnO ₄ 133.3782051

Ba _0.75 La _0.165 Nb ₂ O ₆ 131.7307692
(Ba, Mg) (Ti, Sn) O ₃ 130.0833333
La _0.67 Cu ₃ Ti ₄ O ₁₂ 127.777691
Ba _0.5 Sm _0.333 Nb ₂ O ₆ 125.1410256
Sr _0.80 La _0.20 Ti _0.80 Co _0.20 O ₃ 125.1410256
Sr ₃ Mg _0.33 Nb _4.67 O ₁₅ 1211.8461538
Ba _0.25 Sr _0.75 Nb ₂ O ₆ 116.9038462
Sr _0.46 Ba _0.54 Nb ₂ O ₆ 115.25664103
Ba _0.70 La _0.198 Nb ₂ O ₆ 111.9615385
LaYbO ₃ 111.9615385

BaTi ₄ O ₉ 106.6897436
YBa ₂ Cu ₃ O _(x) 105.3717949
Ba _0.59 Sr _0.32 Ti _1.08 O ₃ 103.3948718
MgNb ₂ O ₆ 103.3948718
Ba _0.60 La _0.264 Nb ₂ O ₆ 102.0769231
ZnMnCoO ₄ 102.0769923
CaNb ₂ O ₆ 95.81666667
(BiFeO ₃ ) _0.9 (BaTiO ₃ ) _0.1 95.48717949
SrBi ₂ B ₄ VO _12.5 85.27307692
Ba _0.9 La _0.066 Nb ₂ O ₆ 82.30769231

Ba _0.9 Sm _0.067 Nb ₂ O ₆ 82.30769231
BaZr _0.25 Nb _1.5 O _5.25 82.30769231
SnNb ₂ O ₇ 82.30769231
ZnCo _0.8 Cr _0.2 MnO ₄ 80.66025641
Sr _0.3 La _0.7 MnO ₃ 79.01282051
Ba _0.80 La _0.20 Ti _0.95 O ₃ 73.74102564
Ba _0.5 O ₃ Sr _0.5 Ti 72.42307692
Ba ₂ Bi ₄ Ti ₅ O ₁₈ 72.42307692
Bi ₂ Cu _0.667 Nb _1.333 O ₇ 72.42307692
Gd ₂ TiZnO ₆ 62.53846154

_{SrBi 2 (Ta, Nb) 2} O 9 62.53846154
Ba ₅ NdTi ₃ Nb ₇ O ₃₀ 59.90256641
Bi ₂ Mg _0.667 Nb _1.333 O ₇ 59.24358974
Ba ₅ NdTi ₂ ZrNb ₇ O ₃₀ 57.92564103
ZnCo _0.2 Cr _0.8 MnO ₄ 5759615385
ZnCo _0.6 Cr _0.4 MnO ₄ 5759615385
Bi ₄ Ti ₃ O ₁₂ 55.948871
Ca _0.85 Y _0.15 Ti _0.85 Co _0.15 O ₃ 55.87871775
Bi ₄ Ti _2.86 Nb _0.14 O ₁₂ 54.63076923
Mg ₂ Nd ₂ SnO ₇ 52.65438415

CoOFe ₂ O ₃ 51.656538462
(SrBi ₂ Ta ₂ O ₉ ) _0.2 (Bi ₃ TiNbO ₉ ) _0.8 49.35898736
(SrBi ₂ Ta ₂ O ₉ ) _0.6 (Bi ₃ TiNbO ₉ ) _0.4 49.0288718
YNdFeSbO ₇ 49.0294718
LaNiO ₃ 48.04102564
Sm ₂ TiZnO ₆ 47.71513846
(Bi _1.5 Zn _0.5 ) (Zn _0.5 Nb _1.5 ) O ₇ 46.06410256
AlNb ₃ O ₉ 46.06410256
Ba ₅ NdTiZr ₂ Nb ₇ O ₃₀ 46.06410256
(SrBi ₂ Ta ₂ O ₉ ) _0.8 (Bi ₃ TiNbO ₉ ) _0.2 45.40512821

Bi ₂ Ti ₂ O ₇ 45.14153546
Mg ₂ Pr ₂ SnO ₇ 44.41666667
Sr _0.5 Ba _0.5 Nb _0.4 Ta _1.6 O ₆ 43.52929472
YPrFeSbO ₇ 43.42820513
Bi ₄ V ₂ O ₁₁ 42.9937436
NdNb ₃ O ₉ 42.76923077
Sn (NbO ₃ ) ₂ 42.76923077
(SrBi ₂ Ta ₂ O ₉ ) _0.4 (Bi ₃ TiNbO ₉ ) _0.6 42.43974359
(SrBi ₂ Nb ₂ O ₉ ) _0.50 (Bi ₃ TiNbO ₉ ) _0.50
42.11025641
YBiFeSbO ₇ 41.78076923

Ba _0.53 Sr _0.24 Ti _1.22 O ₃ 41.45128205
BaTa ₂ O ₆ 41.45128205
YErFeSbO ₇ 41.45128205
Ba _0.984 Sr _0.016 TiO ₃ 41.21179487
YLaFeSbO ₇ 40.79230769
ZnBi _1.5 Nb _1.5 O ₇ 40.49576923
(SrBi ₂ Nb ₂ O ₉ ) _0.25 (Bi ₃ TiNbO ₉ ) _0.75
39.47435897
Bi ₇ Ti ₄ NbO ₂₁ 39.47435897
Ca ₂ Nd ₂ SnO ₇ 39.47435897
(SrBi ₂ Nb ₂ O ₉ ) _0.75 (Bi ₃ TiNbO ₉ ) _0.25
38.48589744

SrMo _0.5 Ni _0.5 O ₃ 38.48589744
YSmFeSbO ₇ 37.4974359
Bi ₂ Zn _0.667 Nb _1.333 O ₇ 37.16794872
Bi ₂ InNbO ₇ 36.8436154
(SrBi ₂ Nb ₂ O ₉ ) _0.40 (Bi ₃ TiNbO ₉ ) _0.60
36.17994818
Bi ₂ SrNb ₂ O ₉ 36.17971818
CaBi ₂ Ta ₂ O ₉ 36.17984718
Mg ₂ La ₂ SnO ₇ 36.17947818
SrTa ₂ O ₆ 36.17948718
BaTa ₂ O ₆ 35.19102564

BaMnTiO ₅ 35.19102564
BaNb ₂ O ₆ 35.170833333
TiNb ₂ O ₇ 35.154358974

  According to the thermal barrier coating material of the present invention, it is possible to provide a thermal barrier coating film with low thermal conductivity, and if the film is used for a thermal barrier coating film applied to the surface of a blade such as a gas turbine, it is excellent. A high-performance gas turbine that can obtain heat resistance and can easily cope with a high temperature of the combustion gas can be obtained.

It is a schematic diagram of the structure | tissue of a thermal barrier coating. It is a phase diagram of MgO-SiO ₂ system. It is a phase diagram of FeO-SiO ₂ system. It is a state diagram of MnO-SiO ₂ system. It is a state diagram of NiO-SiO ₂ system. It is a phase diagram of CoO—SiO ₂ system. It is a phase diagram of FeO-MgO-SiO ₂ system. It is a phase diagram of CaO-MgO-SiO ₂ system. It is a phase diagram of FeO-MnO-SiO ₂ system. It is a phase diagram of MgO-MnO-SiO ₂ system. Mg ₂ is a state diagram of SiO ₄ -Ni ₂ SiO ₄ system. It is the graph which plotted the relationship between the reciprocal number of the refractive index of a dielectric material, and the measured value of thermal conductivity. It is the graph which plotted the relationship between the reciprocal number of the dielectric constant of a dielectric material, and the measured value of thermal conductivity.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compound base material 2 Atmosphere hole of several tens micrometer diameter 3 Small pore of several micrometer diameter 4 Linear pore 5 Linear pore

Claims (20)

  A thermal barrier coating material comprising mainly a dielectric having a refractive index of 2.2 or more at a wavelength of 600 nm at 25 ° C.   A thermal barrier coating material comprising mainly a dielectric having a refractive index of 2.3 or more at a wavelength of 600 nm at 25 ° C.   A thermal barrier coating material comprising mainly a dielectric having a refractive index of 2.4 or more at 25 ° C. and a wavelength of 600 nm.   A thermal barrier coating material comprising mainly a dielectric having a refractive index of 2.5 or more at 25 ° C. and a wavelength of 600 nm.   A thermal barrier coating material comprising mainly a dielectric having a refractive index of 2.6 or more at a wavelength of 600 nm at 25 ° C.   A thermal barrier coating material comprising mainly a dielectric having a refractive index of 2.7 or more at a wavelength of 600 nm at 25 ° C.   A thermal barrier coating material comprising mainly a dielectric having a refractive index of 2.8 or more at a wavelength of 600 nm at 25 ° C.   A thermal barrier coating material comprising mainly a dielectric having a refractive index of 2.9 or more at a wavelength of 600 nm at 25 ° C.   A thermal barrier coating material comprising mainly a dielectric having a refractive index of 3.0 or more at 25 ° C. and a wavelength of 600 nm.   A thermal barrier coating material comprising mainly a dielectric having a refractive index of 4.0 or more at a wavelength of 600 nm at 25 ° C.   A thermal barrier coating material comprising mainly a dielectric having a dielectric constant of 35 or more at 25 ° C. and a frequency of 1 MHz.   A thermal barrier coating material comprising mainly a dielectric having a dielectric constant of 45 or more at 25 ° C. and a frequency of 1 MHz.   A thermal barrier coating material comprising mainly a dielectric having a dielectric constant of 55 or more at 25 ° C. and a frequency of 1 MHz.   A thermal barrier coating material comprising mainly a dielectric having a dielectric constant of 65 or more at 25 ° C. and a frequency of 1 MHz.   A thermal barrier coating material comprising mainly a dielectric having a dielectric constant of 75 or more at 25 ° C. and a frequency of 1 MHz.   A thermal barrier coating material comprising mainly a dielectric having a dielectric constant of 85 or more at 25 ° C. and a frequency of 1 MHz.   A thermal barrier coating material comprising mainly a dielectric having a dielectric constant of 95 or more at 25 ° C. and a frequency of 1 MHz.   A thermal barrier coating material comprising mainly a dielectric having a dielectric constant of 200 or more at 25 ° C. and a frequency of 1 MHz.   A thermal barrier coating material comprising mainly a dielectric having a dielectric constant of 300 or more at 25 ° C. and a frequency of 1 MHz.   A thermal barrier coating material mainly comprising a composition obtained by combining the composition according to claim 1.

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