Effect of surface roughness on properties of PS-PVD YSZ ceramic coating
Jie MAO1,*(), Jing-tao MA1,2, Chang-guang DENG1, Chun-ming DENG1, Jin-bing SONG1, Min LIU1, Peng SONG2
1 The Key Laboratory of Guangdong for Modern Surface Engineering Technology, National Engineering Laboratory for Modern Materials Surface Engineering Technology, Guangdong Institute of New Materials, Guangzhou 510650, China 2 Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China
YSZ ceramic coating was prepared by PS-PVD process on K417G superalloy prefabricated with NiCoCrAlYTa bond coating. The tensile bond strength, particle erosion resistance and high temperature oxidation resistance of PS-PVD YSZ ceramic coating were tested by the universal tensile testing machine, particle erosion device and static oxidation furnace. The SEM and EDS were used to analyze the surface, cross-section morphology and element distribution. The results show that surface roughness has great influence on tensile bond strength, particle erosion resistance and high temperature oxidation resistance of YSZ ceramic coating. The bonding strength is increased first and then decreased with the increase of surface roughness. The coating prepared on the surface of Ra=0.40 μm has the highest bonding strength of 23.5 MPa. The tensile fracture occurs in the interior of YSZ ceramic coating at a distance of 40-70 μm from the bond coating. The erosion rate is decreased first and then increased with the increase of surface roughness. The coating prepared on the surface of Ra=0.40 μm has the best particle erosion resistance, and the erosion rate is 2.8×10-3 g/g. Small surface fluctuations and low porosity are two important reasons for preventing fast particle erosion. The YSZ coatings prepared with different surface roughness can produce dense and continuous TGO layer. Larger surface roughness causes larger fluctuation of growing TGO layer, which is more likely to cause local thickening and stress concentration, thus leading to failure.
ZHENG L , GUO H B , GUO L , et al. New generation thermal barrier coatings for ultrahigh temperature applications[J]. Journal of Aeronautical Materials, 2012, 32 (6): 14- 24.
GUO H B , VAßEN R , STOVER D . Thermophysical properties and thermal cycling behavior of plasma sprayed thick thermal barrier coatings[J]. Surface and Coatings Technology, 2005, 192, 48- 56.
YU H T , MU R D , XIE M , et al. Evolution status and processing technologies of thermal barrier coatings[J]. Chinese Rare Earths, 2010, 31 (5): 83- 88.
SONG P , NAUMENKO D , VAßEN R , et al. Effect of oxygen content in NiCoCrAlY bondcoat on the lifetimes of EB-PVD and APS thermal barrier coatings[J]. Surface and Coatings Technology, 2013, 221, 207- 213.
SHEN Z Y , HE L M , XU Z H , et al. Morphological evolution and failure of LZC/YSZ DCL TBCs by electron beam-physical vapor deposition[J]. Materialia, 2018, 4, 340- 347.
SHEN Z Y , HE L M , XU Z H . Rare earth oxides stabilized La2Zr2O7 TBCs:EB-PVD, thermal conductivity and thermal cycling life[J]. Surface and Coatings Technology, 2019, 357, 427- 432.
Von NIESSEN K , GINDRAT M . Plasma spray-PVD:a new thermal spray process to deposit out of the vapor phase[J]. Journal of Thermal Spray Technology, 2011, 20 (4): 736- 743.
SAMPATH S , SCHULZ U , JARLIGO M O , et al. Processing science of advanced thermal-barrier systems[J]. MRS Bulletin, 2012, 37 (10): 903- 910.
SHINOZAWA A , EGUCHI K , KAMBARA M , et al. Feather-like structured YSZ coatings at fast rates by plasma spray physical vapor deposition[J]. Journal of Thermal Spray Technology, 2010, 19 (1/2): 190- 197.
MAUER G , HOSPACH A , VAßEN R . Process development and coating characteristics of plasma spray-PVD[J]. Surface and Coatings Technology, 2013, 220, 219- 224.
GORAL M , KOTOWSKI S , NOWOTNIK A , et al. PS-PVD deposition of thermal barrier coatings[J]. Surface and Coatings Technology, 2013, 237, 51- 55.
MAO J , DENG Z Q , LIU M , et al. Regional characteristics of YSZ coating prepared by expanded Ar/He/H plasma jet at very low pressure[J]. Surface and Coatings Technology, 2017, 328, 240- 247.
DENG Z Q, MAO J, LIU M, et al. Regional characteristic of 7YSZ coatings prepared by PS-PVD technique[J/OL]. Rare Metals, doi: s12598-018-1041-y.
MAO J , LIU M , DENG C G , et al. Preparation and distribution analysis of thermal barrier coatings deposited on multiple vanes by plasma spray-physical vapor deposition technology[J]. Journal of Engineering Materials and Technology, 2017, 139 (4): 041003.
GAO L H , WEI L L , GUO H B , et al. Deposition mechanisms of yttria stabilized zirconia coatings during plasma spray physical vapor deposition[J]. Ceramics International, 2016, 42 (4): 5530- 5536.
ZHANG X F , ZHOU K S , DENG C G , et al. Gas-deposition mechanisms of 7YSZ coating based on plasma spray-physical vapor deposition[J]. Journal of the European Ceramic Society, 2016, 36 (3): 697- 703.
DENG Z Q , LIU M , MAO J , et al. Stage growth of columnar 7YSZ coating prepared by plasma spray-physical vapor deposition[J]. Vacuum, 2017, 145 (11): 39- 46.
DENG Z Q , ZHANG X F , ZHOU K S , et al. 7YSZ coating prepared by PS-PVD based on heterogeneous nucleation[J]. Chinese Journal of Aeronautics, 2018, 31 (4): 820- 825.
NICHOLLS J R , DEAKIN M J , RICKERBY D S . A comparison between the erosion behaviors of thermal spray and electron beam physical vapor deposition thermal barrier coating[J]. Wear, 1999, 233/235 (3): 352- 361.
WELLMAN R G , NICHOLLS J R . A review of the erosion of thermal barrier coatings[J]. Journal of Physics:D, 2007, 40 (16): 293- 305.