KR101582551B1 - Complex oxides for thermal barrier coating with reduced rare-earth contents and manufacturing method thereof - Google Patents
Complex oxides for thermal barrier coating with reduced rare-earth contents and manufacturing method thereof Download PDFInfo
- Publication number
- KR101582551B1 KR101582551B1 KR1020140073552A KR20140073552A KR101582551B1 KR 101582551 B1 KR101582551 B1 KR 101582551B1 KR 1020140073552 A KR1020140073552 A KR 1020140073552A KR 20140073552 A KR20140073552 A KR 20140073552A KR 101582551 B1 KR101582551 B1 KR 101582551B1
- Authority
- KR
- South Korea
- Prior art keywords
- powder
- oxide ceramics
- composite oxide
- rare earth
- thermal
- Prior art date
Links
Images
Abstract
More particularly, the present invention relates to a low thermal conductivity composite oxide ceramics for use in a rare-earth reduction type high temperature environment heat insulating material and a method for producing the same. More particularly, the present invention relates to a low thermal conductive composite oxide ceramics having the formula A 2 -x Zr 2 O 7-1.5x And 0 < x < 1), and has a fluorite crystal structure, and a method for manufacturing the same.
The low-temperature conductive complex oxide ceramics for high-temperature environment thermal insulation according to the present invention is expensive and can reduce the production cost by reducing the content of rare earth elements which are likely to be unstable in supply and demand, and can be used for non-stoichiometric, The vacancy removed from the rare earth element acts as a point defect to increase the phonon scattering, thereby further reducing the thermal conductivity and increasing the anharmonicity of the bond, (YSZ, stoichiometric rare earth zirconate, etc.), it is equivalent to or better than the conventional material (YSZ, stoichiometric rare earth zirconate, etc.) Can be usefully used.
Description
More particularly, the present invention relates to a low thermal conductive composite oxide ceramics for use in a high temperature environment-friendly thermal insulation, the content of a rare earth element contained in the composite oxide is reduced compared with the conventional one, And a manufacturing method thereof.
Thermal barrier coatings (TBC), which protect superalloy-based metal parts applied to high-temperature parts of power generation or aviation gas turbine engines from hot gases, have been developed to increase the operating temperature of gas turbines in order to increase engine efficiency [Non-Patent Documents 0001 to 0005].
The yttria-stabilized zirconia (YSZ) stabilized with 6-8 wt.% Y 2 O 3 (3.4-4.5 mol% Y 2 O 3 ) as a thermal barrier coating material has a low thermal conductivity and a high thermal expansion coefficient And relatively abundant resources, it has been widely used in the industry. However, there are limitations such as phase transition and high temperature durability deterioration when the temperature is higher than 1200 ° C, Non-Patent Documents 0006 and 0007].
Especially, it is difficult to use existing YSZ at the operating temperature (> 1300 ℃) of recently developed gas turbine. Thermal barrier coating materials that can be applied at temperatures above 1300 ° C should have properties such as high melting point, low thermal conductivity, high thermal expansion coefficient similar to metal base material, phase stability, chemical stability, and low sinterability. Particularly, researches on rare earth zirconate-based oxides of pyrochlore or fluorite structure have been actively carried out [Non-Patent Documents 0008 and 0011].
Rare earth, which is a kind of rare metal, collectively refers to 17 elements including 15 lanthanum elements from element number 57 to 71, scandium 21 and yttrium 39. Rare earths are indispensable materials for permanent magnets, which are essential for low-carbon green growth industries such as electric and hybrid cars, wind power generation, and solar power generation. They are used in the IT industry such as LCD, LED and smart phone, electronic products such as cameras and computers, It is an essential metal for fluorescent materials such as lamps and optical fibers and is indispensable for the development of modern industry as it is called "industrial vitamins".
However, China, which currently supplies 97% of the world's rare earths market, will continue to restrict the production of rare earths in its own country in 2010 and continue to increase its tax burden on rare earths, The development of derealization technologies such as reduction of rare earth use amount, use of substitute element and development of parts with different principle from the past has been spreading all over the world. In Korea, too, the development of technology to cope with the mineralization of rare earth resources in China Movement is taking place.
In such an atmosphere, development of rare earth zirconate-based oxides which can maintain the properties required for thermal barrier coating materials while reducing the content of rare earth elements, which are expensive and have a fear of unstable supply and demand, It is a situation that is required.
SUMMARY OF THE INVENTION The present invention provides a low thermal conductive composite oxide ceramics for a high temperature environmentally-friendly thermal insulation material capable of maintaining or improving thermal properties required for a thermal barrier coating material while reducing the content of rare earth elements and a method for manufacturing the same. will be.
In order to accomplish the above object, the present invention provides a low thermal conductivity composite oxide ceramics for a high temperature environmental thermal spray coating having a fluorite crystal structure represented by the following formula:
[Chemical Formula]
A 2-x Zr 2 O 7 - 1.5x
(Wherein A is Gd, Sm or Dy, 0 < x < = 1).
Also disclosed is a low thermal conductive composite oxide ceramics for high temperature environmental thermal spray coating characterized in that the thermal conductivity at 1000 占 폚 is 2.0 W / mK or less.
Also disclosed is a low thermal conductive composite oxide ceramics for high temperature environmental thermal spray coating characterized by a thermal expansion coefficient at 1000 占 폚 of 10.5 占10-6 / K or more.
The present invention also provides a low thermal conductive composite oxide ceramics for high temperature environment thermal spray coating characterized by having thermal conductivity and thermal expansion coefficient of 1.5 W / mK and 11.5 × 10 -6 / K at 1000 ° C. :
[Chemical Formula]
A 2-x Zr 2 O 7 - 1.5x
(Where A is Gd and x = 0.2).
The present invention also provides a method for producing a zirconium oxide powder, comprising the steps of (a) weighing an A 2 O 3 powder (where A is Gd, Sm or Dy) and ZrO 2 powder in a molar ratio of (2-x) Preparing; (b) mixing the prepared A 2 O 3 powder and ZrO 2 powder; (c) a step of producing a molded body using the mixed powder obtained in the step (b) and sintering the sintered body, A manufacturing method is proposed:
[Chemical Formula]
A 2-x Zr 2 O 7 - 1.5x
(Wherein A is Gd, Sm or Dy, 0 < x < = 1).
In addition, in step (a), more than 42.4 wt% to 59.5 wt% of Gd 2 O 3 powder; And 40.5 wt.% Or more and less than 57.6 wt.% Of ZrO 2 powder are prepared. The present invention also provides a method for producing a low thermal conductive composite oxide ceramics for high temperature environment heat radiation.
Also, in the step (c), a sintering is performed at a temperature of 1500 to 1800 ° C for 1 to 20 hours to form a fluorite single phase, and a method for manufacturing a low thermal conductive composite oxide ceramics for high temperature environment .
Further, the present invention further provides a method for manufacturing a low thermal conductive composite oxide ceramics for high temperature environment heat radiation, which comprises calcining the mixed powder obtained in the step (b) prior to the step (c).
Further, the present invention proposes a method for producing a low thermal conductive composite oxide ceramics for high temperature environment heat radiation, characterized in that the mixed powder is calcined at a temperature lower than the melting point of A 2 O 3 and ZrO 2 for 1 to 100 hours.
The low-temperature conductive complex oxide ceramics for high temperature environmental thermal insulation according to the present invention is expensive, and the content of the rare earth element, which is likely to be unstable in supply and demand, can be reduced compared to the prior art, resulting in a reduction in production cost.
In addition, the low-temperature conductive composite oxide ceramics for high temperature environmental thermal insulation according to the present invention has a non-stoichiometric composition, so that vacancies from which rare-earth elements are removed act as point defects, The thermal conductivity and the thermal expansion rate are increased by increasing the scattering of the material (YSZ, chemical amount, etc.) and the thermal expansion coefficient by increasing the anharmonicity of the bond. Or rare earth rare earth zirconate), it can be used effectively as a material for high quality thermal barrier coating because it is equivalent or rather superior.
FIGS. 1A and 1B are schematic diagrams for 1/8 of a unit cell having a fluorite crystal structure and a unit cell having a pyrochlore crystal structure, respectively.
FIG. 2 is a flowchart of a method for manufacturing a low thermal conductive composite oxide ceramics for a high temperature environment heat shielding in which rare earths are reduced according to the present invention.
2 is a schematic diagram of a suspension plasma spray apparatus used in the present embodiment.
FIG. 3 shows X-ray diffraction (XRD) pattern analysis results of the composite oxide ceramics specimens prepared in Examples 1 to 5 and Comparative Examples of the present invention.
4 is a Raman spectroscopy analysis result of the composite oxide ceramics specimens prepared in Examples 1 to 5 and Comparative Examples of the present invention.
5A to 5F are scanning electron microscope (SEM) photographs of the surfaces of the composite oxide ceramics specimens manufactured in Examples 1 to 5 and Comparative Examples, respectively.
6A and 6B are graphs showing the results of measuring the thermal conductivity of the composite oxide ceramics prepared in Examples 1 to 5 and Comparative Examples according to the temperature changes before porosity correction and after porosity correction, respectively .
FIG. 7 is a graph showing the results of measuring the coefficient of thermal expansion (CTE) of the composite oxide ceramics prepared in Examples 1 to 5 and Comparative Examples according to the temperature change.
Hereinafter, the present invention will be described in detail.
The low thermal conductive composite oxide ceramics for high temperature environment thermal spray coating according to the present invention is characterized by having a fluorite crystal structure represented by the following chemical formula.
[Chemical Formula]
A 2-x Zr 2 O 7 - 1.5x
(Wherein A is Gd, Sm or Dy, 0 < x < = 1).
That is, the composite oxide ceramics according to the present invention is characterized in that the content of the rare earth element is higher than that of rare earth zirconate oxide (A 2 Zr 2 O 7 [where A is Gd, Sm or Dy]) having a stoichiometric composition The stoichiometric composite oxide ceramics having a reduced non-stoichiometric composition and represented by the above-mentioned A 2 Zr 2 O 7 in its crystal structure can be produced by the pyrochlore shown in FIG. 1 (a) Pyrochlore phase, whereas the non-stoichiometric composite oxide ceramics according to the present invention have a difference in that the schematic diagram of the fluorite phase is shown in Fig. 1 (b).
For reference, in the case of the fluorite structure, eight tetrahedral sites (
The above-described low-temperature conductive complex oxide ceramics for high temperature environmental thermal insulation according to the present invention is expensive and can reduce the production cost because the content of the rare earth element having the concern of supply and demand instability is reduced compared with the conventional one.
In addition, the low-temperature conductive composite oxide ceramics for high temperature environmental thermal insulation according to the present invention has a non-stoichiometric composition, so that the vacancy in which rare-earth elements are removed acts as a point defect, The thermal conductivity and the thermal expansion rate are increased by increasing the scattering of the material (YSZ, chemical amount, etc.) and the thermal expansion coefficient by increasing the anharmonicity of the bond. Or rare earth rare earth zirconate), it can be used effectively as a material for high quality thermal barrier coating because it is equivalent or rather superior.
Specifically, the low thermal conductive composite oxide ceramics for high temperature environment thermal spray coating according to the present invention can realize a low thermal conductivity of 2.0 W / mK or less and a high thermal expansion coefficient of 10.5 × 10 -6 / K or more at a high temperature of 1000 ° C. or higher And can be usefully used as a material for a thermal barrier coating for improving the durability of components in a high temperature environment while reducing expensive rare earths.
FIG. 2 is a flow chart showing a method for producing a rare-heat-reduced low-temperature conductive high-temperature conductive composite oxide according to the present invention represented by the following formula and having a fluorite crystal structure.
[Chemical Formula]
A 2-x Zr 2 O 7 - 1.5x
(Wherein A is Gd, Sm or Dy, 0 < x < = 1)
2, the production method according to the present invention is characterized in that (a) an A 2 O 3 powder (where A is Gd, Sm or Dy) and ZrO 2 powder are mixed in a molar ratio of (2-x) , 0 < x? 1]; (b) mixing the prepared A 2 O 3 powder and ZrO 2 powder; (c) preparing a molded body using the mixed powder obtained in the step (b), and sintering the molded body, and each step will be described in detail below.
First, in step (a), a rare earth zirconate oxide having a stoichiometric composition represented by A 2 Zr 2 O 7 (where A is Gd, Sm or Dy) (2-x): 4 (where 0 < x < (x) < 2 >): 4 for the production of the oxide, the powder of one kind of oxide of the lanthanum element such as Gd 2 O 3 , Sm 2 O 3 and Dy 2 O 3 and the ZrO 2 powder, ≤ 1].
For example, when Gd 2 O 3 is used as the rare earth oxide, it can be prepared by weighing 42.4 wt% to 59.5 wt% of Gd 2 O 3 powder and 40.5 wt% to less than 57.6 wt% of ZrO 2 powder.
Next, step (b) is a step of mixing the A 2 O 3 powder and the ZrO 2 powder, which are the raw material powders prepared in the previous step. In the method of forming the mixed powder in this step, the raw materials are uniformly mixed, The specific method is not particularly limited as long as it can be formed and preferably is mechanically mixed through milling using a ball mill, a planetary mill, an attrition mill, or the like This step can be performed through the process.
If necessary, degreasing impurities such as organic substances contained in the mixed powder obtained in the step (b) before carrying out the molding and sintering step of step (c) to be described later after carrying out the step (b) A step of calcining in a vacuum or reducing gas atmosphere may be further carried out. At this time, the calcination is preferably carried out at a temperature and for a time sufficient for the impurities to be completely removed. For example, the calcination is carried out at a temperature lower than the melting point of A 2 O 3 and ZrO 2 , for example, at a temperature of 1200 to 1400 ° C, For 100 hours.
In the step (c), the molded body is manufactured using the mixed powder obtained in the previous step and sintered.
The molding in this step is not limited as far as it is a method for obtaining a molded article having a shape suitable for advancing the sintering process such as press forming, cold isostatic press forming, extrusion forming, powder injection molding and the like. However, It is preferable from the viewpoints of easiness of production of a molded body by a simple method and economy.
The sintering conditions such as the sintering temperature and the pressure and the sintering time in the sintering after the production of the molded body in this step are appropriately selected in consideration of the kind and content of the starting ceramic powder and the microstructure control of the finally produced composite oxide .
For example, when the mixed powder containing Gd 2 O 3 and ZrO 2 is sintered, it is preferable to perform sintering at a temperature of 1500 to 1800 ° C and for 1 to 20 hours. If the sintering temperature is lower than 1500 ° C., sintering is not sufficiently performed. If the sintering temperature is higher than 1800 ° C., there is a problem that the economical efficiency is lowered due to a higher sintering temperature. If the sintering time is less than 1 hour, it is difficult to achieve sufficient sintering. If the sintering time is more than 20 hours, it is not preferable from the viewpoint of cost of the manufacturing process.
Regarding the sintering temperature, arbitrary temperatures T1 and T2 (where T1 < T2) belonging to the selected sintering temperature range are determined in consideration of the kind and content of the starting ceramic powder as described above, Or may be carried out while maintaining the sintering time at a predetermined temperature falling within the sintering temperature range. When sintering is carried out at a predetermined temperature, it may be maintained at a single temperature level or at a plurality of temperature levels. In this case, when the temperature is maintained at a plurality of temperature levels, the holding time at each temperature level may be the same or different can do.
On the other hand, it is preferable that the sintering in this step is carried out in a vacuum atmosphere or an inert atmosphere to prevent the inclusion of impurities.
The composite oxide ceramics obtained by sintering as described above forms a single phase of the fluorite crystal structure.
BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in detail below on the basis of embodiments. The presented embodiments are illustrative and are not intended to limit the scope of the invention.
<Examples 1-5 and Comparative Examples>
Two kinds of starting materials, Gd 2 O 3 (Kojundo Chemical Lab. Co., LTD, 99.9%, 2-3 μm) and ZrO 2 (Kojundo Chemical Lab Co., LTD, 98% In order to synthesize a composite oxide having a composition of Gd 2-x Zr 2 O 7 -1.5x (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) by using an oxide, the composition was weighed so as to have the composition shown in Table 1 below, The balls were mixed with isopropyl alcohol (IPA) as a mixing medium for 24 hours using a ball mill, wet mixed, and heated with stirring to evaporate the solvent. The solvent-evaporated mixture was dried in a dryer at 80 DEG C for 24 hours. The dried powder was pulverized by induction, maintained at 1400 ° C for 2 hours at a heating rate of 5 ° C per minute, and then cooled and calcined. The calcined powders were pulverized with alumina powder, sieved and assembled, and then uniaxially pressed at 50 MPa for 1 minute, heated to 5 ° C / min in an oxidizing atmosphere, sintered at 1600 ° C for 2 hours, .
(
Gd
2
-
x
Zr
2
O
7
-1.5x
)
<Experimental Example 1> Crystal structure analysis of the specimens prepared in Examples 1-5 and Comparative Examples
Fig. 3 shows X-ray diffraction (XRD) analysis results of the specimens prepared in Examples 1-5 and Comparative Examples.
According to Fig. 3, the specimen prepared in the comparative example having a stoichiometric composition had a peak corresponding to the peaks (331) and (511), that is, a characteristic peak for distinguishing the pyrochlore crystal phase from the fluorite crystal phase, In the case of the specimens prepared in Examples 1 to 5, the peaks are not shown, while the regular arrangement of the cations in the chloe structure and the oxygen vacancies at the specific positions indicate superlattice peaks existing in the unit cell, (See red double dotted line segment).
That is, the rare earth-reducing complex oxide specimen according to the present invention exhibits a fluorite crystal structure, while the specimen showing a stoichiometric composition has a pyrochlore crystal structure, which is different from that of the crystal phase.
Meanwhile, FIG. 4 shows Raman spectroscopic results of the specimens prepared in Examples 1-5 and Comparative Examples. As shown in FIG. 4, in the case of the sample prepared in the comparative example having a stoichiometric composition, about 320 cm -1 , 410cm -1, and there are about peaks clearly appear at a frequency of 520cm -1 shows the wider is finally disappears as, a decrease Gd content in the oxide composition, the gadolinium ion and oxygen for such a phenomenon is present in a specific position in the crystal (E g , T 2g and A 1g ), which is related to the oscillation of the ion-to-ion bond, indicating a phase change from pyrochlore to the fluorite phase, Match.
<Experimental Example 2> Observation of surface microstructure of the specimens prepared in Examples 1-5 and Comparative Examples
The surface microstructures of the specimens prepared in Examples 1 to 5 and Comparative Examples were observed using a scanning electron microscope (SEM), and the results are shown in Figs. 5 (a) to 5 (f).
The specimens prepared in the comparative examples having a stoichiometric composition showed dense microstructures having almost no pores (see FIG. 5 (f)). In the case of the specimens prepared in Examples 1 to 5, Except for the specimens, large pores were distributed evenly or large pores were found in some places.
For reference, the relative densities of the specimens prepared in Examples 1 to 5 were measured as 96.3%, 97.3%, 98.7%, 96.8% and 95.3%, respectively.
<Experimental Example 3> Measurement of thermal properties of the specimens prepared in Examples 1-5 and Comparative Examples
Thermal conductivity was measured for each of the specimens prepared in Examples 1 to 5 and Comparative Examples, and the results are shown in Fig. 6 (a).
For reference, thermal conductivity was calculated from the following formula using measured apparent density (ρ), specific heat (C p ), and thermal diffusivity (λ), where apparent density was measured using the Archimedes method using distilled water, The thermal diffusivity was measured by laser flash analysis while heating from room temperature to 1000 ° C.
Κ = ρ · C p · λ
Referring to FIG. 6 (a), the thermal conductivities of the specimens prepared in Examples 1 to 5 at 1000 ° C. were similar to those of the specimens prepared in the comparative example having a stoichiometric composition, The specimens prepared in Example 1 and Comparative Example 2 exhibited lower thermal conductivities than those of the comparative specimens. In particular, the specimens prepared in Example 1 showed a low thermal conductivity of about 1.5 W / mK.
On the other hand, FIG. 6 (b) is a graph showing the relationship between the crystal structure of the material constituting the test piece and the thermal conductivity caused by defects (point defects, intergranular) by excluding the influence of pores in the measurement results shown in FIG. 5 Fig.
K measured / K true = 1-4 / 3?
(K measured : thermal conductivity measurement value, K true : original thermal conductivity of material, and?: Porosity)
Referring to FIG. 6 (b), the thermal conductivities of the specimens prepared in Examples 1 to 5 at 1000 ° C. were slightly higher than those of the comparative examples having a stoichiometric composition The thermal conductivity of the specimens prepared in Examples 1 and 2 was still lower than that of the comparative specimens.
For reference, considering that the densified YSZ known in the literature has a thermal conductivity of 2.0 to 2.5 W / mK from room temperature to 1000 ° C, the rare earth reduced complex oxide ceramics prepared in Examples 1 to 5 are comparable to YSZ And it is expected that the heat shielding effect will be excellent.
FIG. 7 is a graph showing the measured thermal conductivity coefficient of thermal expansion (CTE) for each of the specimens prepared in Examples 1 to 5 and Comparative Example. The rare earth reduced complex oxide specimens prepared in Examples 1 to 5 exhibited almost the same level or higher thermal expansion coefficient as the specimens of the comparative example having a stoichiometric composition, and in particular, the specimens prepared in Example 1 had a modulus of about 11.5 x 10 < -6 / K. When the rare earth-reduced complex oxide according to the present invention is applied to a thermal barrier coating, the strain compliance with the metal base material is expected to be excellent.
Claims (9)
[Chemical Formula]
A 2-x Zr 2 O 7 - 1.5x
(Wherein A is Gd, Sm or Dy, 0 < x < = 1).
[Chemical Formula]
A 2- x Zr 2 O 7 -1.5x
(Where A is Gd and x = 0.2).
(b) mixing the prepared A 2 O 3 powder and ZrO 2 powder;
(c) a step of producing a molded body using the mixed powder obtained in the step (b) and sintering the sintered body, Manufacturing method:
[Chemical Formula]
A 2-x Zr 2 O 7 - 1.5x
(Wherein A is Gd, Sm or Dy, 0 < x < = 1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020140073552A KR101582551B1 (en) | 2014-06-17 | 2014-06-17 | Complex oxides for thermal barrier coating with reduced rare-earth contents and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020140073552A KR101582551B1 (en) | 2014-06-17 | 2014-06-17 | Complex oxides for thermal barrier coating with reduced rare-earth contents and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR20150144581A KR20150144581A (en) | 2015-12-28 |
| KR101582551B1 true KR101582551B1 (en) | 2016-01-05 |
Family
ID=55084877
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020140073552A KR101582551B1 (en) | 2014-06-17 | 2014-06-17 | Complex oxides for thermal barrier coating with reduced rare-earth contents and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR101582551B1 (en) |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0947487A1 (en) * | 1998-03-31 | 1999-10-06 | Haldor Topsoe A/S | Fluorite ceramic material |
-
2014
- 2014-06-17 KR KR1020140073552A patent/KR101582551B1/en active IP Right Grant
Also Published As
| Publication number | Publication date |
|---|---|
| KR20150144581A (en) | 2015-12-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wang et al. | Transparent ceramics: Processing, materials and applications | |
| An et al. | Fabrication of transparent lutetium oxide by spark plasma sintering | |
| Zhou et al. | Effect of manganese oxide on the sintered properties of 8YSZ | |
| He et al. | Study on microstructure and thermal conductivity of spark plasma sintering AlN ceramics | |
| Wang et al. | Spark-plasma-sintered barium zirconate based proton conductors for solid oxide fuel cell and hydrogen separation applications | |
| Shilong et al. | Study of Sm0. 2Ce0. 8O1. 9 (SDC) electrolyte prepared by a simple modified solid-state method | |
| Zhang et al. | Vacuum sintering of transparent Cr: Y2O3 ceramics | |
| US20160104551A1 (en) | Yttria based conductive plasma-resistant member and methods thereof | |
| JP4894379B2 (en) | Rare earth sintered body and manufacturing method thereof | |
| Yoshida et al. | Doping effect on the flash sintering of Y2O3: promotion of densification and optical translucency | |
| An et al. | Fabrication of transparent La2Zr2O7 by reactive spark plasma sintering | |
| Gan et al. | Fabrication of submicron-grained IR-transparent Y2O3 ceramics from commercial nano-raw powders | |
| Zhou et al. | Microstructure and mechanical properties of 8YSZ ceramics by liquid-phase sintering with CuO-TiO2 addition | |
| Esposito et al. | Reactive sintering of YAG-based materials using micrometer-sized powders | |
| Wang et al. | Investigation of La3+ doped Yb2Sn2O7 as new thermal barrier materials | |
| KR101582551B1 (en) | Complex oxides for thermal barrier coating with reduced rare-earth contents and manufacturing method thereof | |
| Arellano et al. | Densification behavior of spark plasma sintered La2O3–YSZ ceramic composites | |
| Kosyanov et al. | Reactive SPS of Nd3+: YAG transparent ceramics with LiF sintering additive | |
| Kim et al. | Effect of ZnO and TiO2 doping on the sintering behavior of Y2O3 ceramics | |
| Zhu et al. | Effects of the Zr concentration on transparent Y 2 O 3 ceramics fabricated by vacuum pre-sintering and a subsequent HIP treatment | |
| KR20170078505A (en) | Method for manufacturing thermal barrier coating with reduced rare-earth contents using suspension plasma spraying | |
| Li et al. | Increasing the sinterability of tape cast oxalate-derived doped ceria powder by ball milling | |
| Bernard-Granger et al. | Comparisons of grain size-density trajectory during spark plasma sintering and hot-pressing of zirconia | |
| Sévin et al. | Structural stability of hafnia-based materials at ultra-high temperature | |
| KR20170032836A (en) | Complex oxides for thermal barrier coating having reduced rare-earth contents and pyrochlore-fluorite dual structure and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GRNT | Written decision to grant | ||
| FPAY | Annual fee payment |
Payment date: 20191204 Year of fee payment: 5 |