Zirconia-based ceramic target material synergistically modified by rare earth oxide and TiO2 as well as preparation method and application of zirconia-based ceramic target material

Abstract

The invention provides a rare earth oxide and TiO2 synergistically modified zirconia-based ceramic target material and a preparation method and application thereof.The ceramic target material comprises a base material and a modification stabilizer, the base material is yttrium-stabilized zirconia, the modification stabilizer comprises TiO2 and rare earth oxide, and the rare earth oxide is one or a mixture of more of Eu2O3, Nd2O3, Ge2O3 and Tb2O3. According to the rare earth oxide and TiO2 synergistically modified zirconia-based thermal barrier coating ceramic target material, through the synergistic effect of the rare earth oxide and TiO2, the thermal conductivity of a coating is remarkably reduced, the CMAS corrosion resistance is enhanced, grains are refined, the fracture toughness is improved, meanwhile, the sintering temperature is reduced, energy consumption is reduced, and the rare earth oxide and TiO2 synergistically modified zirconia-based thermal barrier coating ceramic target material is suitable for preparing a high-performance thermal barrier coating.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of thermal barrier coating materials, and particularly relates to a rare earth oxide and TiO2 synergistically modified zirconia-based ceramic target material and a preparation method and application thereof. BACKGROUND

[0002] With the development of aero-engines towards high thrust-to-weight ratio, increased service life and efficiency, the engine inlet temperature is also increased. TBCs can effectively reduce the metal surface temperature and become one of the key technologies for preparing high-performance aero-engine turbine blades. At present, the most widely used is yttrium stabilized zirconia (YSZ) coating material, but it is prone to phase change at a high temperature of 1200 DEG C or above, which causes the volume expansion of the coating, resulting in coating cracking, sintering, reduction of the heat insulation performance of the ceramic layer and shortening of the service life, etc., which has become an important factor restricting the safe use of YSZ coating at a higher temperature. SUMMARY

[0003] Therefore, the application aims to overcome the defects in the prior art and provides a rare earth oxide and TiO2 synergistically modified zirconia-based ceramic target material and a preparation method and application thereof.

[0004] To achieve the above-mentioned purpose, the technical scheme of the application is as follows: In a first aspect, the application provides a rare earth oxide and TiO2 synergistically modified zirconia-based ceramic target material, which comprises a base material and a modified stabilizer, the base material is yttrium stabilized zirconia, the modified stabilizer comprises TiO2 and a rare earth oxide, and the rare earth oxide is a mixture of one or more of Eu2O3, Nd2O3, Ge2O3 and Tb2O3.

[0005] Preferably, the addition amount of TiO2 is 0.5-1wt% of the total mass of the base material and the rare earth oxide, and the addition amount of the rare earth oxide is 2-5wt% of the total mass of the base material and the rare earth oxide.

[0006] Preferably, the mass percentage of yttrium oxide in the base material is 6-9wt%.

[0007] In a second aspect, the application further provides a preparation method of the above-mentioned rare earth oxide and TiO2 synergistically modified zirconia-based ceramic target material, which comprises the following steps: Step one: ball-milling yttrium stabilized zirconia and a rare earth oxide and then high-temperature solid-phase reaction; Step two: crushing the block obtained after the high-temperature solid-phase reaction and then secondary ball-milling to obtain a solid solution powder; Step three: adding TiO2 and a binder to the solid solution powder, stirring and spray granulating; Step four: the powder is isostatically pressed to form a target blank, and the blank is trimmed in size and shape; Step five: the target blank is sintered at low temperature by using a segmented heating method to obtain a ceramic target.

[0008] Preferably, the reaction conditions of the high-temperature solid-phase reaction in step one are sintering at 1400-1500℃ for 5-10h.

[0009] Preferably, the amount of the binder added in step three is 1-2wt% of the solid solution powder.

[0010] Preferably, the binder is a PVA aqueous solution with a concentration of 10wt%.

[0011] Preferably, the low-temperature sintering in step five is performed according to the following steps: Starting from room temperature, the temperature is raised to 300℃ at a rate of 0.5-2℃, and then kept at 300℃ for 0.5-2h. Then the temperature is raised to 600℃ at a rate of 0.5-2℃, and then kept at 600℃ for 0.5-2h. Then the temperature is raised to 800-1000℃ at a rate of 1-3℃, and then kept at 800-1000℃ for 3-6h. Finally, the furnace is cooled to room temperature.

[0012] Preferably, the ball milling in step one is performed according to the following steps: deionized water is used as the dispersant, the ratio of the material to the ball is 1:1, the ratio of the material to the water is 3:1, and the ball milling is performed for 8-10h.

[0013] Preferably, the secondary ball milling in step two is performed according to the following steps: deionized water is used as the dispersant, the ratio of the material to the ball is 1:1, the ratio of the material to the water is 3:1, and the ball milling is performed for 10-15h.

[0014] In a third aspect, the application also provides a use of the above-mentioned ceramic target in the field of thermal barrier coatings.

[0015] The multi-component rare earth oxide-doped YSZ has high-temperature phase stability and low thermal conductivity, and has other thermal physical properties and mechanical properties comparable to those of YSZ. Moreover, the single-layer structure can avoid the problem of interface mismatching caused by the multi-layer structure. In addition, the incorporation of rare earth oxides can react with CMAS to form a dense layer, hinder the deepening of corrosion, and increase the service life of the coating.

[0016] TiO2 is a widely used sintering aid. It can introduce lattice defects in various oxide ceramic systems through solid solution doping, and cooperatively reduce the grain boundary energy and promote material diffusion, thereby significantly reducing the sintering temperature and optimizing the microstructure. Its core role lies in effectively reducing the kinetic barrier of the sintering process.

[0017] The rare earth oxide is added in the YSZ substrate prepared by a solid phase method, the heat scattering capacity is increased, the thermal conductivity of the thermal barrier coating is significantly reduced, the rare earth element can form a dense layer on the surface of the coating to hinder the corrosion of CMAS, and the addition of the rare earth oxide can increase the lattice distortion of the yttrium stabilized zirconia substrate, increase the sintering driving force; meanwhile, the addition of TiO2 promotes the sintering of the target material, further reduces the sintering temperature, reduces the energy consumption, refines the grains, obtains higher fracture toughness, and makes the target material not easy to produce cracks during transportation, installation and electron beam thermal shock.

[0018] The rare earth oxide and TiO2 cooperatively modified zirconia-based thermal barrier coating ceramic target of the application significantly reduces the thermal conductivity of the coating, enhances the CMAS corrosion resistance, refines the grains and improves the fracture toughness, reduces the sintering temperature and saves energy consumption, and is suitable for the preparation of high-performance thermal barrier coatings.

[0019] Compared with the prior art, the application has the following advantages: The application realizes performance optimization based on rare earth oxide doped YSZ ceramic materials, the addition of the rare earth oxide causes local lattice distortion to be intensified, the distortion can enhance phonon scattering or increase the cooperative scattering of phonons and photons to dominate heat conduction, so that the thermal conductivity of the thermal barrier coating is reduced. Meanwhile, the rare earth oxide is easy to react with the CMAS molten salt in the service environment of the thermal barrier coating, inhibits the penetration of the molten salt into the coating, and improves the corrosion resistance of the coating.

[0020] The TiO2 in the application can form silicate or titanate eutectic liquid phase with ZrO2 and trace impurities (such as SiO2 and Al2O3) in the system and YSZ itself at a relatively low temperature. The existence of the liquid phase layer greatly promotes the rate of material migration, narrows the distance between particles, and thus rapidly densifies. The ionic radius (0.605 Å) of Ti 4+ is different from the ionic radius (0.72 Å) of Zr 4+ . When Ti 4+ is doped into the ZrO2 lattice, it will cause lattice distortion and produce a stress field. In order to maintain electrical neutrality, this doping may introduce oxygen vacancies, which significantly accelerate the diffusion of O 2-The diffusion of ions in the crystal lattice increases the diffusion rate of ions, and thus promotes the densification process. The combined effect of the above two effects provides a faster path (liquid phase) and more "carriers" (oxygen vacancies) for atomic migration, thereby significantly reducing the activation energy of the sintering process and reducing the sintering temperature. Combined with the lattice distortion caused by rare earth oxides to the matrix, the target material can be densified and sintered at a lower temperature, which not only improves the performance of the coating but also greatly reduces the sintering temperature, thereby achieving the purpose of energy saving. And by reducing the sintering temperature and inhibiting the migration of grain boundaries, composite doping helps to obtain a fine and uniform microstructure, improve the fracture toughness of the target material, and make the target material less likely to crack during transportation, installation or under the impact of electron beam heat. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Scanning electron microscope image of the ceramic target material of Example 1; Figure 2 Scanning electron microscope image of the ceramic target material of Example 2; Figure 3 Scanning electron microscope image of the ceramic target material of Example 3. DETAILED DESCRIPTION

[0022] Embodiments of the present application are described in detail below. The embodiments described below are exemplary only, and are not to be construed as limiting the present application.

[0023] In the present text, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0024] In the present text, where values are described as ranges, it is to be understood that the disclosure includes disclosure of all possible sub-ranges within the range, and specific numerical values falling within the range, regardless of whether the specific numerical values or specific sub-ranges are explicitly stated.

[0025] In the present text, references to "a plurality" or the like, unless otherwise specified, mean greater than or equal to two in number. For example, "one or more" means one or more than two.

[0026] In the present text, references to "preferably", "more preferably" are only to describe embodiments or examples with better effects, and it should be understood that they do not constitute a limitation on the scope of protection of the present application.

[0027] In the present text, references to "further" or the like are used for descriptive purposes, indicating differences in content, but should not be understood as limiting the scope of protection of the present application.

[0028] In this document, the term "and / or" is an associative relationship describing the object, which means that there can be three relationships. For example, A and / or B, means: A or B, or A and B, three kinds of relationship.

[0029] In this document, the term "about" means + / - 10% of the specified value, preferably + / - 5%, more preferably + / - 1%.

[0030] In this document, "including", "including", "including", "including" and the like are all open terms, that is, it means including but not limited to.

[0031] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as generally understood by those skilled in the art to which the present application relates. Although the present application only describes the preferred method and material, any method and material similar or equivalent to that described herein can also be used in the implementation or test of the present application.

[0032] The present application will be described in detail below in conjunction with examples.

[0033] Example 1 Step one: put 97wt% of YSZ raw material and 3wt% of Eu2O3 powder into a ball mill tank for mixing and ball milling, with deionized water as dispersant, the ratio of material to ball is 1:1, the ratio of material to water is 3:1, ball milling for 10h, then sintering at 1500℃ for 10h, so that YSZ and Eu2O3 occur solid phase reaction.

[0034] Step two: crush the block material after sintering of YSZ and Eu2O3 after solid solution, and then ball mill the crushed powder with water as dispersant for 13h, the ratio of material to ball is 1:1, the ratio of material to water is 3:1, to obtain the powder after solid solution.

[0035] Step three: add deionized water, powder after solid solution, 0.5wt% of TiO2 powder based on the powder after solid solution, 1.5wt% of PVA aqueous solution with a concentration of 10wt% based on the powder after solid solution, in a blender, stirring at 1000rpm for 1h, then spray granulating the mixed slurry, with inlet temperature of 200℃ and outlet temperature of 200℃, to obtain the granulated powder.

[0036] Step four: put the powder into an isostatic pressing mold, shake it, press it at 150MPa for 5min, form the target blank by isostatic pressing, and trim the size and shape of the blank.

[0037] Step five: put the target blank into a sintering furnace for sintering, with sintering schedule as follows: start from room temperature, heat up to 300℃ at a rate of 1.5℃, keep for 1h, heat up to 600℃ at a rate of 2℃, keep for 1h, heat up to 1000℃ at a rate of 2.5℃, keep for 6h, then cool down to room temperature with the furnace, to obtain the ceramic target.

[0038] After incorporating Eu₂O₃ and TiO₂, the ceramic target exhibits a uniform morphology and a grain size of less than 10 μm. Figure 1 As shown, the specific fracture energy of the target material is 89.25 J / mm. 2 The thermal barrier coating prepared from this target material was compared with the traditional YSZ thermal barrier coating material, and the thermal conductivity of this material can be reduced by 10-15%.

[0039] Example 2 Step 1: Mix 95wt% YSZ raw material and 5wt% Tb2O3 powder in a ball mill jar, using deionized water as the dispersant. The material-to-ball ratio is 1:1 and the material-to-water ratio is 3:1. After ball milling for 10 hours, sinter at 1650℃ for 10 hours to allow YSZ and Tb2O3 to undergo a solid-phase reaction.

[0040] Step 2: Crush the block raw material after sintering YSZ and Tb2O3 after solid solution treatment, and ball mill the crushed powder again with water as a dispersant for 15 hours, wherein the material-to-ball ratio is 1:1 and the material-to-water ratio is 3:1, to obtain the solid solution powder.

[0041] Step 3: Add deionized water, dissolved powder, 0.8 wt% TiO2 powder, and 2 wt% PVA aqueous solution to the mixer. Stir at 1000 rpm for 1 hour. Spray granulate the mixture at an inlet temperature of 200℃ and an outlet temperature of 200℃ to obtain granulated powder.

[0042] Step 4: Place the powder into an isostatic pressing mold, vibrate to compact it, hold the pressure at 200MPa for 5 minutes, and form a target blank through isostatic pressing. Then, trim the size and shape of the blank.

[0043] Step 5: Place the target blank into a sintering furnace for sintering. The sintering regime is as follows: start from room temperature, increase the temperature to 300℃ at a rate of 1.5℃, hold for 1 hour, increase the temperature to 600℃ at a rate of 2℃, hold for 1 hour, increase the temperature to 950℃ at a rate of 2.5℃, hold for 6 hours, and then cool with the furnace to room temperature to obtain the ceramic target.

[0044] After incorporating Tb₂O₃ and TiO₂, the ceramic target exhibits a uniform morphology and a grain size of less than 10 μm. Figure 2 As shown, the specific fracture energy of the target material is 91.13 J / mm. 2 The thermal barrier coating prepared from this target material was compared with the traditional YSZ thermal barrier coating material, and the thermal conductivity of this material can be reduced by 25-30%.

[0045] Example 3 Step 1: Mix 95wt% YSZ raw material and 5wt% GeO2 powder in a ball mill jar, using deionized water as the dispersant. The material-to-ball ratio is 1:1 and the material-to-water ratio is 3:1. After ball milling for 10 hours, sinter at 1500℃ for 10 hours to allow YSZ and GeO2 to undergo a solid-phase reaction.

[0046] Step 2: Crush the block raw material after solidification and sintering of YSZ and GeO2, and ball mill the crushed powder again for 12 hours with water as a dispersant, wherein the material-to-ball ratio is 1:1 and the material-to-water ratio is 3:1, to obtain the solidified powder.

[0047] Step 3: Add deionized water, dissolved powder, 1 wt% TiO2 powder, and 1.5 wt% PVA aqueous solution to the mixer. Stir at 1000 rpm for 1 hour. Spray granulate the mixture at an inlet temperature of 200℃ and an outlet temperature of 200℃ to obtain granulated powder.

[0048] Step 4: Place the powder into an isostatic pressing mold, vibrate to compact it, hold the pressure at 250MPa for 5 minutes, and form a target blank through isostatic pressing. Then, trim the size and shape of the blank.

[0049] Step 5: Place the target blank into a sintering furnace for sintering. The sintering regime is as follows: start from room temperature, increase the temperature to 300℃ at a rate of 1.5℃ and hold for 1 hour, increase the temperature to 600℃ at a rate of 2℃ and hold for 1 hour, increase the temperature to 900℃ at a rate of 2.5℃ and hold for 6 hours, and then cool it to room temperature with the furnace to obtain the ceramic target.

[0050] After incorporating GeO2 and TiO2, the ceramic target exhibits a uniform morphology and a grain size of less than 10 μm, such as... Figure 3 As shown, the specific fracture energy of the target material is 93.22 J / mm. 2 The thermal barrier coating prepared from this target material was compared with the traditional YSZ thermal barrier coating material, and the thermal conductivity of this material can be reduced by 20-30%.

[0051] Comparative Example 1 Step 1: Mix 95wt% YSZ raw material and 5wt% GeO2 powder in a ball mill jar, using deionized water as the dispersant. The material-to-ball ratio is 1:1 and the material-to-water ratio is 3:1. After ball milling for 10 hours, sinter at 1500℃ for 10 hours to allow YSZ and GeO2 to undergo a solid-phase reaction.

[0052] Step 2: Crush the block raw material after solidification and sintering of YSZ and GeO2, and ball mill the crushed powder again for 12 hours with water as a dispersant, wherein the material-to-ball ratio is 1:1 and the material-to-water ratio is 3:1, to obtain the solidified powder.

[0053] Step three: add deionized water, solid-solution powder, 10wt% PVA solution with a concentration of 1.5wt% of the solid-solution powder into a blender, stir at 1000rpm for 1h, spray granulate the mixed slurry, inlet temperature is 200℃, outlet temperature is 200℃, to obtain granulated powder.

[0054] Step four: put the powder into an isostatic pressing mold, shake it, press at 250MPa for 5min, isostatic pressing to form a target blank, and trim the size and shape of the blank.

[0055] Step five: put the target blank into a sintering furnace for sintering, the sintering schedule is as follows: from room temperature to 300℃ at a rate of 1.5℃, hold for 1h, from 300℃ to 600℃ at a rate of 2℃, hold for 1h, from 600℃ to 1000℃ at a rate of 2.5℃, hold for 6h, then cool to room temperature in the furnace, to obtain a ceramic target.

[0056] When only rare earth oxide is added without adding TiO2, the specific fracture energy of the target is reduced to 34.43J / mm 2 The thermal barrier coating prepared from the target can reduce the thermal conductivity of the traditional YSZ thermal barrier coating material by 20-30%.

[0057] Comparative example 2 Step one: mix and ball mill YSZ raw material 95wt% and GeO2 powder 5wt% in a ball mill tank, use deionized water as dispersant, the ratio of material to ball is 1:1, the ratio of material to water is 3:1, ball mill for 10h, then sinter at 1500℃ for 10h to make YSZ and GeO2 react by solid phase.

[0058] Step two: crush the block of solid-solution YSZ and GeO2 sintered raw material, ball mill the crushed powder again with water as dispersant for 12h, the ratio of material to ball is 1:1, the ratio of material to water is 3:1, to obtain solid-solution powder.

[0059] Step three: add deionized water, solid-solution powder, 10wt% PVA solution with a concentration of 1.5wt% of the solid-solution powder into a blender, stir at 1000rpm for 1h, spray granulate the mixed slurry, inlet temperature is 200℃, outlet temperature is 200℃, to obtain granulated powder.

[0060] Step four: put the powder into an isostatic pressing mold, shake it, press at 250MPa for 5min, isostatic pressing to form a target blank, and trim the size and shape of the blank.

[0061] Step five: the target blank is put into a sintering furnace to be sintered, the sintering system is as follows: starting from room temperature, heating to 300℃ at a rate of 1.5℃, keeping for 1h, heating to 600℃ at a rate of 2℃, keeping for 1h, heating to 1000℃ at a rate of 2.5℃, keeping for 6h, and then cooling to room temperature in the furnace, to obtain the ceramic target.

[0062] When excess TiO2 is added, the specific fracture energy of the target is increased to 99.89 J / mm 2 However, the thermal conductivity of the target can only be reduced by 5-10%, because the addition of too much TiO2 makes the target too dense, which has a reverse effect on the thermal conductivity of the target, and because the difference in the thermal expansion coefficient between TiO2 and the yttrium-stabilized zirconia matrix is too large, the excessive addition will reduce the stability of the target.

[0063] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A zirconia-based ceramic target modified with rare earth oxide in cooperation with TiO2, characterized by: The ceramic target material comprises a substrate and a modified stabilizer, the substrate is yttrium stabilized zirconia, and the modified stabilizer comprises TiO2 and rare earth oxide, and the rare earth oxide is a mixture of one or more of Eu2O3, Nd2O3, Ge2O3 and Tb2O3.

2. The zirconia-based ceramic target modified synergistically with rare earth oxide and TiO2 according to claim 1, characterized in that: The addition amount of TiO2 is 0.5-1wt% of the total mass of the substrate and the rare earth oxide, and the addition amount of the rare earth oxide is 2-5wt% of the total mass of the substrate and the rare earth oxide.

3. The zirconia-based ceramic target material of claim 1, wherein: The mass percentage of yttrium oxide in the substrate is 6-9wt%.

4. Process for the production of a zirconia-based ceramic target modified with TiO2 and rare earth oxides, according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: Step one: high-temperature solid-phase reaction after ball milling of yttrium stabilized zirconia and rare earth oxide; Step two: crushing and secondary ball milling of the block after high-temperature solid-phase reaction to obtain a solid solution powder; Step three: adding TiO2 and a binder to the solid solution powder for stirring and spray granulation; Step four: isostatic pressing of the powder to obtain a target blank, and size and shape trimming of the blank; Step five: low-temperature sintering of the target blank in a segmented heating mode to finally obtain a ceramic target material.

5. The method of claim 4, wherein the method is characterized by: The reaction conditions of the high-temperature solid-phase reaction in step one are sintering at 1400-1500℃ for 5-10h.

6. The method of claim 4, wherein the method is characterized by: The addition amount of the binder in step three is 1-2wt% of the mass of the solid solution powder.

7. The method of claim 4, wherein the method is characterized by: The binder is a PVA aqueous solution with a concentration of 10wt%.

8. The method of claim 4, wherein the method is characterized by: The specific steps of the low-temperature sintering in step five are as follows: Starting from room temperature, heating at a rate of 0.5-2℃ to 300℃, holding for 0.5-2h, heating at a rate of 0.5-2℃ to 600℃, holding for 0.5-2h, heating at a rate of 1-3℃ to 800-1000℃, holding for 3-6h, and then cooling to room temperature in the furnace.

9. The method of claim 4, wherein the method is characterized by: The specific steps of the ball milling in step one are as follows: using deionized water as a dispersant, a material-to-ball ratio of 1:1, a material-to-water ratio of 3:1, and ball milling for 8-10h; The specific steps of the secondary ball milling in step two are as follows: using deionized water as a dispersant, a material-to-ball ratio of 1:1, a material-to-water ratio of 3:1, and ball milling for 10-15h.

10. Use of the ceramic target material of any one of claims 1-3 in the field of thermal barrier coatings.

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