EB-PVD制备热障涂层的反射光谱特性研究
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摘要
为了研究航空发动机中涡轮叶片表面的热障涂层对辐射光谱的反射特性,本文使用真空电弧镀法在不锈钢基体上分别制备了NiCrAlYSi和NiCoCrAlYHf两种热障涂层的粘结层,并随后使用电子束物理气相沉积(EB-PVD)法制备了ZrO_2·Y_2O_3(YSZ)热障涂层的陶瓷面层,最后利用紫外-可见-近红外分光光度计测定了常温下热障涂层在0.3μm～2.5μm波段的反射率光谱并进行了分析研究。结果表明:金属粘结层和陶瓷面层厚度均相同时,不同的粘结层材料对热障涂层的光谱反射率影响不大,整个波段内NiCrAlYSi/YSZ和NiCoCrAlYHf/YSZ涂层的光谱反射率接近。当粘结层NiCrAlYSi的厚度相同,面层YSZ的厚度分别为20μm、100μm、170μm三种不同厚度时,热障涂层的光谱反射率表现出不同的特性,在0.3μm～0.45μm波段,厚度为20μm的YSZ的试样因表面呈蓝紫色反射紫光能力最强,而灰白色的其他两个试样反射紫光能力接近;在0.45μm～2.5μm波段,YSZ涂层厚度与光谱反射率正相关,涂层厚度越厚光谱反射率越高。通过调整电子束物理气相沉积工艺制备了YSZ微叠层,与相同厚度的传统柱状晶的YSZ相比,YSZ微叠层的光谱反射率提高了约一倍。
In order to study the spectral reflectance characteristics of the thermal barrier coatings deposited on the surface of turbine blades in aero-engines, the NiCrAlYSi and NiCoCrAlYHf bondcoat of thermal barrier coatings(TBCs) were deposited on the 304 stainless steel substrate by vacuum arc ion plating and the topcoat of YSZ was deposited by EB-PVD. The spectral reflectance of TBCs within a wavelength range of 0.3 to 2.5 μm at room temperature was measured by UV-VIS-NIR spectrophotometer. The results show that no matter which kind of bondcoat is, the reflectance spectra of the NiCrAlYSi/YSZ and NiCoCrAlYHf/YSZ with the same thickness of bondcoat and topcoat are very close in the whole wavelength band. The spectral reflectance of the NiCrAlYSi/YSZ coat shows different characteristics under the topcoat thickness of 20, 100 and 170μm. Within the wavelength range from 0.3 to 0.45 μm, the coating with a 20 μm topcoat shows the strongest reflct ability on purple light,while the other two grayish-white sample show similar ability. Reflectance has a positive relativity to the YSZ thickness in the0.45 to 2.5 μm wavelength range. Compared with that of the conventional YSZ, the spectral reflectance of micro laminate deposited by modified EB-PVD process is improved by two times.
In order to study the spectral reflectance characteristics of the thermal barrier coatings deposited on the surface of turbine blades in aero-engines, the NiCrAlYSi and NiCoCrAlYHf bondcoat of thermal barrier coatings(TBCs) were deposited on the 304 stainless steel substrate by vacuum arc ion plating and the topcoat of YSZ was deposited by EB-PVD. The spectral reflectance of TBCs within a wavelength range of 0.3 to 2.5 μm at room temperature was measured by UV-VIS-NIR spectrophotometer. The results show that no matter which kind of bondcoat is, the reflectance spectra of the NiCrAlYSi/YSZ and NiCoCrAlYHf/YSZ with the same thickness of bondcoat and topcoat are very close in the whole wavelength band. The spectral reflectance of the NiCrAlYSi/YSZ coat shows different characteristics under the topcoat thickness of 20, 100 and 170μm. Within the wavelength range from 0.3 to 0.45 μm, the coating with a 20 μm topcoat shows the strongest reflct ability on purple light,while the other two grayish-white sample show similar ability. Reflectance has a positive relativity to the YSZ thickness in the0.45 to 2.5 μm wavelength range. Compared with that of the conventional YSZ, the spectral reflectance of micro laminate deposited by modified EB-PVD process is improved by two times.
引文
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[11]牟仁德,贺世美,何利民,等.微叠层结构EB-PVD热障涂层[J].航空材料学报,2009,29(3):55-60.
[2]Limarga A M,Widjaja S,Yip T H.Mechanical properties and oxidation resistance of plasma-sprayed multilayered Al2O3/Zr O2thermal barrier coatings[J].Surface and Coatings Technology,2005,197:93-102.
[3]何利民,等.高温防护涂层技术[M].北京:国防工业出版社,2012.
[4]曹学强.热障涂层材料[M].北京:科学出版社,2007.
[5]Huang X.High temperature radiation heat transfer performance of thermal barrier coatings with multiple layered structures[J].Journal of Engineering for Gas Turbines and Power,2009,131,011301:1-7.
[6]Nicholls J R,Lawson K J,Johnstoneb A,et al.Methods to reduce the thermal conductivity of EB-PVD TBCs[J].Surface and Coatings Technology,2002,151-152:383-391.
[7]Eldridge J I,Spuckler C M,Street K W,et al.Infrared radiative properties of Yttria-stabilized zirconia thermal barrier coatings[J].Journal of American Ceramic Society,2002,13-18:417-430.
[8]Eldridge J I,Spuckler C M.Determination of Scattering and Absorption Coefficients for Plasma-Sprayed Yttria-Stabilized Zirconia Thermal Barrier Coatings[J].Journal of the American Ceramic Society,2008,91(5):1603-1611.
[9]Huang X,Wang D M,Patnaik P,et al.Design and computational analysis of highly reflective multiple layered thermal barrier coating structure[J].Materials Science and Engineering A,2007,460-461:101-110.
[10]Wang D M,Huang X,Patnaik P.Design and modeling of multiple layered TBC system with high reflectance[J].Journal of Materials Science,2006,41:6245-6255.
[11]牟仁德,贺世美,何利民,等.微叠层结构EB-PVD热障涂层[J].航空材料学报,2009,29(3):55-60.