A high fracture toughness layered perovskite structure high entropy thermal barrier coating material and preparation method thereof

Abstract

The present invention discloses a high-fracture-toughness layered perovskite structure high-entropy thermal barrier coating material and a preparation method thereof. The present invention relates to the technical field of thermal barrier coating materials. The present invention discloses a high-fracture-toughness layered perovskite structure high-entropy thermal barrier coating material, whose chemical formula is BaLn2Ti3O 10 , Ln is selected from at least three of La, Ce, Pr, Nd, and Sm. The preparation method comprises weighing the respective rare earth oxides, BaCO3, and nano-TiO2 according to the chemical formula, mixing them, and wet-ball milling them. The milled mixture precursor is filtered, cleaned, and dried, and then pre-calcined and calcined to produce a layered perovskite structured high-entropy thermal barrier coating material. This invention utilizes high-entropy design by screening for differences in rare earth ion size and mass, thereby proposing a novel multi-principal element doping system. The resulting phase is highly stable even at high temperatures, while also improving the fracture toughness of the layered perovskite structure.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal barrier coating materials, and in particular to a layered perovskite structure high-entropy thermal barrier coating material with high fracture toughness and a preparation method thereof. Background Art

[0002] Thermal barrier coatings (TBCs) are inorganic thermal protective coatings that provide a low-thermal-conductivity heat shield between alloy components and substrates, reducing the surface temperature of turbine blades in high-temperature environments. With their low thermal conductivity and excellent corrosion resistance, TBCs effectively protect aircraft engine hot-end components and extend the service life of turbine blades. However, the most widely used 6-8% YSZ TBC material undergoes phase transformation and cracking at 1200°C, making it unsuitable for practical use.

[0003] Among the many alternative materials, layered perovskite materials and their derivatives have the advantages of low thermal conductivity, good corrosion resistance and low cost, and are expected to become candidates for thermal barrier coating materials.

[0004] Layered perovskite BaLn2Ti3O 10 The material can be viewed as a triple perovskite layer separated by weakly bonded Ba-O layers along the c-axis, showing a high degree of anisotropy. 10 The crystal belongs to the monoclinic system. The insertion of weakly bonded Ba-O layers can serve as a barrier to phonon conduction, thereby reducing the thermal diffusion coefficient and giving the material good high-temperature performance. However, due to its layered structure, the powder is prone to exfoliation during high-temperature service and has poor mechanical properties. Summary of the Invention

[0005] The purpose of the present invention is to address the above-mentioned deficiencies in the prior art and to provide a layered perovskite structured high entropy thermal barrier coating material with high fracture toughness and a preparation method thereof.

[0006] The present invention provides a high fracture toughness layered perovskite structure high entropy thermal barrier coating material, the chemical formula of which is BaLn2Ti3O 10 , Ln is selected from at least three of La, Ce, Pr, Nd, and Sm.

[0007] Furthermore, Ln is La, Nd, Sm, and / or Ce, and / or Pr.

[0008] Furthermore, Ln=La, Nd, Sm, forming a ternary high entropy ceramic Ba(La 1 / 3 Nd 1 / 3 Sm 1 / 3 )2Ti3O 10 .

[0009] Furthermore, Ln=La, Pr, Nd, Sm, forming a quaternary high entropy ceramic Ba(La 1 / 4 Pr 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 .

[0010] Furthermore, Ln=La, Ce, Nd, Sm, forming a quaternary high entropy ceramic Ba(La 1 / 4 Ce 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 .

[0011] Furthermore, Ln=La, Ce, Pr, Nd, Sm, forming a five-element high entropy ceramic Ba(La 1 / 5 Ce 1 / 5 Pr 1 / 5 Nd 1 / 5 Sm 1 / 5 )2Ti3O 10 .

[0012] A method for preparing a layered perovskite structure high entropy thermal barrier coating material with high fracture toughness as described above comprises weighing rare earth oxides, BaCO3, and nano-TiO2 according to a chemical formula, mixing them and wet-ball milling them, filtering, cleaning, and drying the ball-milled mixture precursor, and then pre-calcining and calcining them to obtain a layered perovskite structure high entropy thermal barrier coating material.

[0013] Furthermore, the steel is pre-fired at 800-900°C for 5 hours and then calcined at 1200-1500°C for 5-100 hours.

[0014] Further, drying is carried out at 70-120° C. for 5-12 hours.

[0015] Furthermore, the liquid in the wet ball milling was isopropyl alcohol, the rotation speed was set to 3000 rps / min, and the ball milling was performed for a total of 5 h.

[0016] The present invention performs high entropy design by screening out the size and mass differences of rare earth ions, and proposes a new multi-principal element doping system. The phase generated after doping is also very stable at high temperatures, while also improving the fracture toughness of the layered perovskite structure.

[0017] The present invention uses the mature ball milling method to prepare the powder, which has a relatively low cost. By regulating the process parameters, the obtained powder has good fracture toughness. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is Ba(La in Example 1 of the present invention 1 / 4 Pr 1 / 4Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 XRD patterns of the materials after calcination at 1500 °C for 10 h and 100 h;

[0019] Figure 2 is Ba(La in Example 1 of the present invention 1 / 4 Pr 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 Microstructure of the material after being heated at 1500℃ for 10h;

[0020] Figure 3 is Ba(La in Example 2 of the present invention 1 / 4 Pr 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 and Ba(La 1 / 3 Nd 1 / 3Sm 1 / 3 )2Ti3O 10 Mechanical properties;

[0021] Figure 4 is Ba(La in Example 3 of the present invention 1 / 5 Ce 1 / 5 Pr 1 / 5 Nd 1 / 5 Sm 1 / 5 )2Ti3O 10 XRD patterns of the materials after calcination at 1500 °C for 10 h and 100 h;

[0022] Figure 5 is Ba(La in Example 3 of the present invention 1 / 5 Ce 1 / 5 Pr 1 / 5 Nd 1 / 5 Sm 1 / 5 )2Ti3O 10 Microstructure of the material after being heated at 1500℃ for 10h;

[0023] Figure 6 is Ba(La in Example 4 of the present invention 1 / 3 Nd 1 / 3 Sm 1 / 3 )2Ti3O 10 XRD patterns of the materials after calcination at 1500 °C for 10 h and 100 h;

[0024] Figure 7 is Ba(La in Example 4 of the present invention 1 / 3 Nd 1 / 3 Sm1 / 3 )2Ti3O 10 Microstructure of the material after being heated at 1500℃ for 10h;

[0025] Figure 8 1 is the XRD pattern of the materials prepared in Example 1 and Comparative Example 1 after calcination at 1500° C. for 10 h. DETAILED DESCRIPTION

[0026] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0027] Example 1

[0028] According to the composition formula Ba(La 1 / 4 Pr 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 The compound represented by the Ln position is (La 1 / 4 Pr 1 / 4Nd 1 / 4 Sm 1 / 4 ), La2O3, Nd2O3, Sm2O3, Pr2O3, BaCO3 and nano-TiO2 were weighed and put into a high-energy ball mill, 700-800g of zirconia ball milling beads with a diameter of 0.1-0.2mm and 100-150mL of isopropanol were added to the high-energy ball mill, the high-energy ball mill was installed, the program was set, the speed was set to 3000rps / min, and the ball milling was carried out for a total of 5 hours; the mixture precursor after ball milling was filtered and cleaned, and then the evaporating dish containing the liquid was placed in a drying oven at 70-120℃ and dried for more than 5-12 hours. The dried powder was pre-calcined at 850℃ for 5 hours, the pre-calcined powder was ground, sieved, PVA granulated, and then pressed into shape, and then calcined at 1500℃ for 10 hours to obtain Ba(La 1 / 4 Pr 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 The thermal expansion coefficient of the material is 11.66×10 -6 K -1 .

[0029] Figure 1 is Ba(La in Example 1 1 / 4 Pr 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10XRD phase analysis after the material was calcined at 1500℃ for 10h and 100h showed that the powder phase after doping was stable, no impurity phase was produced, and no phase change occurred, indicating that the material has good high-temperature phase stability.

[0030] Figure 2 is Ba(La in Example 1 1 / 4 Pr 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 Microstructure after heating at 1500℃ for 10h.

[0031] Example 2

[0032] According to the composition formula Ba(La 1 / 4 Pr 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 The compound represented by the Ln position is (La 1 / 4 Pr 1 / 4Nd 1 / 4 Sm 1 / 4 ), La2O3, Nd2O3, Sm2O3, Pr2O3, BaCO3 and nano-TiO2 were weighed and put into a high-energy ball mill, 700-800g of zirconia ball milling beads with a diameter of 0.1-0.2mm and 100-150mL of isopropanol were added to the high-energy ball mill, the high-energy ball mill was installed, the program was set, the speed was set to 3000rps / min, and the ball milling was carried out for 5 hours; the mixture precursor after ball milling was filtered and cleaned, and then the evaporating dish containing the liquid was placed in a drying oven at 70-120℃ and dried for more than 5-12 hours. The dried powder was pre-calcined at 850℃ for 5 hours, the pre-calcined powder was ground and sieved, and then calcined at 1500℃ for 10 hours to obtain Ba(La 1 / 4 Pr 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 Material.

[0033] The obtained powder was spark plasma sintered at a heating rate of 100°C / min under the conditions of 20 MPa and 1450°C for 5 min, and then the surface was ground and polished for fracture toughness testing.

[0034] Figure 3 is Ba(La in Example 2 1 / 4 Pr 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 The mechanical properties of Ba(La1 / 4Pr 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 The fracture toughness is relatively high at 2.41 MPa·m 1 / 2 , than the Ba(La 1 / 3 Nd 1 / 3Sm 1 / 3 )2Ti3O 10 11% higher, comparable to 8YSZ.

[0035] Example 3

[0036] According to the composition formula Ba(La 1 / 5 Ce 1 / 5 Pr 1 / 5 Nd 1 / 5 Sm 1 / 5 )2Ti3O 10 The compound represented by the Ln position is (La 1 / 5Ce 1 / 5 Pr 1 / 5 Nd 1 / 5 Sm 1 / 5 ), La2O3, Nd2O3, Sm2O3, Pr2O3, Ce2O3, BaCO3 and nano-TiO2 were weighed and put into a high-energy ball mill, 700-800g of zirconia ball milling beads with a diameter of 0.1-0.2mm and 100-150mL of isopropanol were added to the high-energy ball mill, the high-energy ball mill was installed, the program was set, the speed was set to 3000rps / min, and the ball milling was carried out for a total of 5 hours; the mixture precursor after ball milling was filtered and cleaned, and then the evaporating dish containing the liquid was placed in a drying oven at 70-120℃ and dried for more than 5-12 hours. The dried powder was pre-calcined at 850℃ for 5 hours, the pre-calcined powder was ground, sieved, PVA granulated, and then pressed into shape, and then calcined at 1500℃ for 10 hours to obtain Ba(La 1 / 5 Ce 1 / 5 Pr 1 / 5 Nd 1 / 5 Sm 1 / 5 )2Ti3O 10 The thermal expansion coefficient of the material is 10.41×10 -6 K -1 .

[0037] Figure 4 is Ba(La in Example 3 1 / 5 Ce 1 / 5 Pr 1 / 5 Nd 1 / 5 Sm 1 / 5 )2Ti3O 10XRD phase analysis after the material was calcined at 1500℃ for 10h and 100h showed that the doped powder phase was stable, no impurity phase was produced, and no phase change occurred, indicating that the material has good high-temperature phase stability.

[0038] Figure 5 is Ba(La in Example 3 1 / 5 Ce 1 / 5 Pr 1 / 5 Nd 1 / 5 Sm 1 / 5 )2Ti3O 10 Microstructure after heating at 1500℃ for 10h.

[0039] Example 4

[0040] According to the composition formula Ba(La 1 / 3 Nd 1 / 3 Sm 1 / 3 )2Ti3O 10 The compound represented by the Ln position is (La 1 / 3 Nd 1 / 3Sm 1 / 3 ), La2O3, Nd2O3, Sm2O3, BaCO3 and nano-TiO2 were weighed and put into a high-energy ball mill, 700-800g of zirconia ball milling beads with a diameter of 0.1-0.2mm and 100-150mL of isopropanol were added to the high-energy ball mill, the high-energy ball mill was installed, the program was set, the speed was set to 3000rps / min, and the ball milling was carried out for a total of 5 hours; the mixture precursor after ball milling was filtered and cleaned, and then the evaporating dish containing the liquid was placed in a drying oven at 70-120℃ and dried for more than 5-12 hours. The dried powder was pre-calcined at 850℃ for 5 hours, the pre-calcined powder was ground, sieved, PVA granulated, and then pressed into shape, and then calcined at 1500℃ for 10 hours to obtain Ba(La 1 / 3 Nd 1 / 3 Sm 1 / 3 )2Ti3O 10 The thermal expansion coefficient of the material is 11.47×10 -6 K -1 .

[0041] Figure 6 is Ba(La in Example 4 1 / 3 Nd 1 / 3 Sm 1 / 3 )2Ti3O 10 XRD phase analysis after the material was calcined at 1500℃ for 10h and 100h showed that the doped powder phase was stable, no impurity phase was produced, and no phase change occurred, indicating that the material has good high-temperature phase stability.

[0042] Figure 7is Ba(La in Example 4 1 / 3 Nd 1 / 3 Sm 1 / 3 )2Ti3O 10 Microstructure after heating at 1500℃ for 10h.

[0043] Example 5

[0044] According to the composition formula Ba(La 1 / 3 Nd 1 / 3 Sm 1 / 3 )2Ti3O 10 The compound represented by the Ln position is (La 1 / 3 Nd 1 / 3Sm 1 / 3 ), weigh La2O3, Nd2O3, Sm2O3, BaCO3 and nano-TiO2 respectively and put them into a high-energy ball mill, add 700-800g of zirconia ball milling beads with a diameter of 0.1-0.2mm and 100-150mL of isopropanol into the high-energy ball mill, install the high-energy ball mill, set the program, set the speed to 3000rps / min, and ball mill for 5 hours; filter and clean the mixture precursor after ball milling, and then put the evaporating dish containing the liquid into a drying oven at 70-120℃ and dry it for more than 5-12 hours. The dried powder is pre-calcined at 850℃ for 5 hours, the pre-calcined powder is ground and sieved, and then calcined at 1500℃ for 10 hours to obtain Ba(La 1 / 3 Nd 1 / 3Sm 1 / 3 )2Ti3O 10 Material.

[0045] The obtained powder was spark plasma sintered at a heating rate of 100°C / min under the conditions of 20 MPa and 1450°C for 5 min, and then the surface was ground and polished for fracture toughness testing.

[0046] Figure 3 is Ba(La in Example 5 1 / 3 Nd 1 / 3 Sm 1 / 3 )2Ti3O 10 The mechanical properties of Ba(La 1 / 3 Nd 1 / 3Sm 1 / 3 )2Ti3O 10 Fracture toughness is 2.17 MPa·m 1 / 2 The elastic modulus is 148.3 GPa, slightly lower than Ba(La 1 / 4 Pr 1 / 4 Nd 1 / 4Sm 1 / 4 )2Ti3O 10158.8GPa, brittleness of 2.71μm 1 / 2 Slightly higher than Ba(La 1 / 4 Pr 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 2.42μm 1 / 2 .

[0047] Comparative Example 1

[0048] According to the composition formula Ba(La 1 / 4 Ce 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 The compound represented by the Ln position is (La 1 / 4 Ce 1 / 4Nd 1 / 4 Sm 1 / 4 ), weigh La2O3, Nd2O3, Sm2O3, Ce2O3, BaCO3 and nano-TiO2 respectively and put them into a high-energy ball mill, add 700-800g of zirconia ball milling beads with a diameter of 0.1-0.2mm and 100-150mL of isopropanol into the high-energy ball mill, install the high-energy ball mill, set the program, set the speed to 3000rps / min, and ball mill for 5 hours; filter and clean the mixture precursor after ball milling, and then put the evaporating dish containing the liquid into a drying oven at 70-120℃ and dry it for more than 5-12 hours. The dried powder is pre-calcined at 850℃ for 5 hours, and the pre-calcined powder is ground, sieved, PVA granulated, pressed into shape, and then calcined at 1500℃ to obtain Ba(La 1 / 4 Ce 1 / 4 Nd 1 / 4 Sm 1 / 4 )2Ti3O 10 Material.

[0049] Figure 8 The XRD patterns of the materials prepared in Example 1 and Comparative Example 1 after calcination at 1500°C for 10 h are shown in FIG. Figure 8 It can be seen that a large amount of secondary phase appears in the material prepared in Comparative Example 1.

[0050] Any matters not mentioned above shall be subject to the existing technology.

[0051] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are for illustration only and are not intended to limit the scope of the present invention. Those skilled in the art of the present invention may make various modifications or additions to the described specific embodiments or replace them in similar ways, but they will not deviate from the direction of the present invention or exceed the scope defined by the appended claims. Those skilled in the art should understand that any modifications, equivalent replacements, improvements, etc. made to the above embodiments based on the technical essence of the present invention should be included in the scope of protection of the present invention.

Claims

1. A layered perovskite structured high-entropy thermal barrier coating material with high fracture toughness, characterized by: Its chemical formula is BaLn2Ti3O 10 , Ln = La, Pr, Nd, Sm, forming a quaternary high entropy ceramic Ba(La 1∕4 Pr 1∕4 Nd 1∕4 Sm 1∕4 )2Ti3O 10 ; Ln = La, Ce, Pr, Nd, Sm, forming a five-element high entropy ceramic Ba(La 1∕5 Ce 1∕5 Pr 1∕5 Nd 1∕5 Sm 1∕5 )2Ti3O 10 .

2. A method for preparing the layered perovskite structured high-entropy thermal barrier coating material with high fracture toughness as claimed in claim 1, characterized in that: According to the chemical formula, each rare earth oxide, BaCO3 and nano-TiO2 are weighed and mixed by wet ball milling. The ball-milled mixture precursor is filtered, cleaned and dried, and then pre-calcined and calcined to obtain a layered perovskite structure high entropy thermal barrier coating material.

3. The preparation method according to claim 2, wherein: First pre-sinter at 800~900 ℃ for 5 h, and then calcinate at 1200~1500 ℃ for 5~100 h.

4. The preparation method according to claim 2, wherein: Dry at 70~120℃ for 5-12h.

5. The preparation method according to claim 2, wherein: The liquid in the wet ball milling was isopropyl alcohol, the speed was set at 3000 rps / min, and the ball milling was carried out for a total of 5 h.

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