CERAMIC MATERIAL FOR THERMAL BARRIER COATING AND MANUFACTURING METHOD THEREOF

Abstract

The present disclosure provides a ceramic material for a thermal barrier coating and a manufacturing method thereof. A chemical composition of the ceramic material is LaYbZrCeO7. The ceramic material is manufactured by doping LaO1.5, YbO1.5 and CeO2 into ZrO2. A mole ratio of LaO1.5, YbO1.5, CeO2 and ZrO2 is 1:1:1:1. The manufactured ceramic material is in a composite phase structure mainly including a pyrochlore phase and a fluorite phase. The ceramic material according to the present disclosure can effectively inhibit corrosion penetration of molten CMAS in a high temperature environment, which reduces or avoids ceramic cracking and peeling. This better maintains microstructural integrity of the ceramic surface, thereby extending service life of ceramics.

Claims

1. A ceramic material for a thermal barrier coating, wherein a chemical composition of the ceramic material is LaYbZrCeO.sub.7.

2. The ceramic material according to claim 1, wherein the ceramic material is manufactured by doping LaO.sub.1.5, YbO.sub.1.5 and CeO.sub.2 into ZrO.sub.2.

3. The ceramic material according to claim 2, wherein a mole ratio of LaO.sub.1.5, YbO.sub.1.5, CeO.sub.2 and ZrO.sub.2 is 1:1:1:1.

4. The ceramic material according to claim 2, wherein the manufactured ceramic material is in a composite phase structure mainly comprising a pyrochlore phase and a fluorite phase.

5. The ceramic material according to claim 2, wherein the ceramic material still maintains good microstructural integrity, after calcium-magnesium-alumina-silicate (CMAS) corrodes the ceramic material at a temperature of 1250? C. for 30 minutes.

6. A manufacturing method of the ceramic material according to claim 1, comprising: S1. placing powders La.sub.2O.sub.3, Yb.sub.2O.sub.3, ZrO.sub.2 and CeO.sub.2 respectively in a box dryer for drying and heat preservation, to remove residual impurities; S2. weighing the powders in a mole ratio of 25LaO.sub.1.5-25YbO.sub.1.5-25ZrO.sub.2-25CeO.sub.2, dissolving the powders in pure alcohol, and performing mechanical ball milling, to obtain a mixed product; S3. drying the mixed product in a vacuum drying oven and taking it out, to obtain a dry fine powder for later use; S4. cold-pressing the obtained dry fine powder into a ceramic body at 350-400 MPa, and performing pressureless sintering in a tube furnace at 1550-1600? C., to manufacture the ceramic material.

7. The manufacturing method of the ceramic material according to claim 6, wherein in S1, in the box dryer, a drying temperature is set to 100-110? C., and the heat preservation is performed for 3-4 hours.

8. The manufacturing method of the ceramic material according to claim 6, wherein in S2, the mechanical ball milling is performed at 350-400 r/min for 8-10 hours.

9. The manufacturing method of the ceramic material according to claim 6, wherein in S3, the mixed product is dried in the vacuum drying oven at 65-70? C. for 24-30 hours and then taken out.

10. The manufacturing method of the ceramic material according to claim 6, wherein the obtained dry fine powder is cold-pressed into the ceramic body at 350-400 MPa for 5-10 minutes, and the pressureless sintering is performed in the tube furnace at 1550-1600? C. for 12-14 hours.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 shows macroscopic schematic diagrams of ceramic material samples for thermal barrier coatings after coating CMAS: (a) La.sub.2Zr.sub.2O.sub.7, and (b) LaYbZrCeO.sub.7.

[0028] FIG. 2 shows cross-sectional morphologies (1250? C., 5 minutes) of ceramic material samples for thermal barrier coatings after CMAS corrosion: (a) La.sub.2Zr.sub.2O.sub.7, and (b) LaYbZrCeO.sub.7.

[0029] FIG. 3 shows ceramic cross-sectional morphologies (1250? C., 30 minutes) of ceramic material samples for thermal barrier coatings after CMAS corrosion: (a) La.sub.2Zr.sub.2O.sub.7, and (b) LaYbZrCeO.sub.7.

DETAILED DESCRIPTION OF EMBODIMENTS

[0030] The present disclosure will be detailed in the following through specific embodiments. However, the use and purpose of these exemplary embodiments are merely used to exemplify the present disclosure, do not limit the actual protection scope of the present disclosure in any form, and do not limit the protection scope of the present invention to this.

Embodiment 1

[0031] The manufacturing method of a ceramic material for a thermal barrier coating according to this embodiment includes the following steps: [0032] S1. Powders La.sub.2O.sub.3, Yb.sub.2O.sub.3, ZrO.sub.2 and CeO.sub.2 (purities 99.99%) are placed in a box dryer respectively, and heat preservation is performed for 3 hours at a temperature of 100? C., to remove residual impurities (i.e., removing adsorbed water or carbon dioxide). [0033] S2. The powders are weighed according to a ratio of 25LaO.sub.1.5-25YbO.sub.1.5-25ZrO.sub.2-25CeO.sub.2 (mol %), dissolved in pure alcohol, and undergo mechanical ball milling at 350 r/min for 8 hours, to obtain a mixed product. [0034] S3. The mixed product is dried in a vacuum drying oven at 65? C. for 24 hours, and then taken out, to obtain a dry fine powder for later use. [0035] S4. The obtained dry fine powder is cold-pressed into a ceramic body at 350 MPa for 5 minutes, and undergoes pressureless sintering in a tube furnace at 1550? C. for 12 hours, to manufacture a ceramic bulk sample LaYbZrCeO.sub.7 (? 10 mm?3 mm).

[0036] The manufactured ceramic bulk sample LaYbZrCeO.sub.7 (hereinafter referred to as the ceramic sample LaYbZrCeO.sub.7) is compared with a ceramic bulk sample La.sub.2Zr.sub.2O.sub.7 (hereinafter referred to as the ceramic sample La.sub.2Zr.sub.2O.sub.7), to better show that the ceramic sample LaYbZrCeO.sub.7 has CMAS high-temperature corrosion resistance performance.

[0037] FIG. 1 shows macroscopic schematic diagrams of the ceramic sample La.sub.2Zr.sub.2O.sub.7 and the ceramic sample LaYbZrCeO.sub.7 after coating CMAS.

[0038] As shown in FIG. 1, the CMAS (33CaO-9MgO-13AlO.sub.1.5-45SiO.sub.2, mol %) powder was uniformly coated on a surface of the ceramic sample La.sub.2Zr.sub.2O.sub.7 and a surface of the ceramic sample LaYbZrCeO.sub.7, with a concentration of 15 mg/cm.sup.2.

[0039] FIG. 2 shows cross-sectional morphologies (1250? C., 5 minutes) of the ceramic sample La.sub.2Zr.sub.2O.sub.7 and the ceramic sample LaYbZrCeO.sub.7 after CMAS corrosion.

[0040] As shown in FIG. 2(a), the ceramic sample La.sub.2Zr.sub.2O.sub.7 is severely corroded by the molten CMAS, forming a loose and micro-cracked reaction layer of a thickness of about 2.7 m, and the CMAS has completely filled the cracks. However, a reaction layer in the ceramic sample LaYbZrCeO.sub.7 has a depth of only 1.5 m (FIG. 2(b)), and is relatively dense with only a few cracks, which indicates that the LaYbZrCeO.sub.7 has good CMAS high-temperature corrosion resistance performance.

Embodiment 2

[0041] On the basis of embodiment 1, FIG. 3 shows cross-sectional morphologies (1250? C., 30 minutes) of the ceramic sample La.sub.2Zr.sub.2O.sub.7 and the ceramic sample LaYbZrCeO.sub.7 after CMAS corrosion.

[0042] As shown in FIG. 3(a), the microstructure of the ceramic sample La.sub.2Zr.sub.2O.sub.7 is severely damaged, with a large number of ceramic particles peeled into the CMAS to form a reaction layer of a thickness of about 6.2 ?m, which indicates that the La.sub.2Zr.sub.2O.sub.7 has poor CMAS high-temperature corrosion resistance performance. However, the ceramic sample LaYbZrCeO.sub.7 only has a small number of ceramic particles peeled off, thus maintaining good microstructural integrity, and the depth of its reaction layer is only 4.0 ?m. This once again shows that the ceramic sample LaYbZrCeO.sub.7 has excellent CMAS high-temperature corrosion resistance performance.

[0043] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present disclosure, they are not intended to limit the scope of protection of the present disclosure, and any equivalent embodiment or modification made without departing from the technical spirit of the present disclosure should be included in the scope of protection of the present disclosure.