等离子喷涂La2Zr2O7热障涂层高温烧结的硬化行为

唐春华,李广荣,刘梅军,杨冠军,李长久

中国表面工程 ›› 2020, Vol. 33 ›› Issue (2) : 119-126.

PDF(13993 KB)
PDF(13993 KB)
中国表面工程 ›› 2020, Vol. 33 ›› Issue (2) : 119-126. DOI: 10.11933/j.issn.1007-9289.20191014001
表面工程

等离子喷涂La2Zr2O7热障涂层高温烧结的硬化行为

  • 唐春华,李广荣,刘梅军,杨冠军,李长久
作者信息 +

Sintering-stiffening Behavior of Plasma Sprayed La2 Zr2 O7 Thermal Barrier Coatings During High Temperature Exposure

  • Tang Chunhua, Li Guangrong, Liu Meijun, Yang Guanjun, Li Changjiu
Author information +
文章历史 +

摘要

热障涂层在高温服役过程中发生烧结和硬化,是引发涂层开裂和剥离失效的主要因素,因此掌握涂层烧结规律是进行涂层设计制备、寿命预测和工艺优化的前提。 文中采用等离子喷涂技术制备 La2 Zr2 O7热障涂层,在 1250 ℃ 条件下进行涂层高温热暴露试验,表征了涂层高温烧结过程中力学性能的变化规律,从孔隙结构的角度揭示了涂层高温烧结硬化机理。 研究结果表明,喷涂态 La2 Zr2 O7 涂层为典型的层状结构,硬度为(405±20) HV0.3 ,高温热暴露后涂层呈现先快后慢的硬化趋势,热暴露 200 h 后涂层硬度提高了 80%。 涂层结构分析表明,涂层物相保持不变,但涂层孔隙率呈现出先快后慢的下降规律。 坐标轴变换处理后发现,硬度和孔隙率均呈现以 10 h 为临界的双阶段特性。 通过对涂层孔隙结构的高温准原位观察,发现涂层孔隙初期多点桥接超快愈合、后期以边界推进方式缓慢烧结的双阶段烧结现象, 从而揭示了 La2 Zr2 O7 热障涂层分阶段硬化的烧结机理,从而为发展抗烧结高性能热障涂层提供了新的理论依据。

Abstract

The sintering of thermal barrier coatings leads to the stiffening during high temperature service, and thereby causes coating cracking and peeling failure. Therefore, understanding the coating sintering law is the premise of coating design, prepa- ration, lifetime prediction and process optimization. La2 Zr2 O7thermal barrier coatings were prepared by plasma spraying technol- ogy. The high temperature thermal exposure test of coating was carried out at 1250 ℃ . Firstly, the mechanical properties of the coating during high temperature sintering were characterized. Subsequently, the high temperature sintering-stiffening mechanism of the coating was revealed from the perspective of pore structure. Results show that the as-sprayed La2 Zr2 O7coating is a typical layered structure with a hardness of (405±20) HV0.3. The coating exhibits a first fast sintering and then slow hardening tendency after high temperature exposure, and the coating hardness after 200 h thermal exposure is increased by 80%. The analysis of the coating structure shows that the phase of the coating remaines unchanged, but the porosity of the coating shows a first fast de- crease and then slow decline. After the coordinate axis transformation, it is found that both hardness and porosity exhibites a two- stage characteristic with a critical duration of 10 h. The quasi-in-situ observation of the pore structure suggests that the initial healing of pores proceeds very fast in a form of multi-point contact, and that the subsequent healing slows down in a form of sin-gle-contact and growth. Therefore, this can be responsible for the two-stage sintering mechanism of the La2 Zr2 O7, which makesfundamental contribution for the development of high performance thermal barrier coatings.

关键词

等离子喷涂; 热障涂层; La2 Zr2 O7 ; 烧结; 孔隙愈合

Key words

plasma spraying; thermal barrier coatings; La2 Zr2 O7 ; sintering; pore healing

引用本文

导出引用
唐春华,李广荣,刘梅军,杨冠军,李长久. 等离子喷涂La2Zr2O7热障涂层高温烧结的硬化行为[J]. 中国表面工程, 2020, 33(2): 119-126 https://doi.org/10.11933/j.issn.1007-9289.20191014001
Tang Chunhua, Li Guangrong, Liu Meijun, Yang Guanjun, Li Changjiu. Sintering-stiffening Behavior of Plasma Sprayed La2 Zr2 O7 Thermal Barrier Coatings During High Temperature Exposure[J]. China Surface Engineering, 2020, 33(2): 119-126 https://doi.org/10.11933/j.issn.1007-9289.20191014001

参考文献

[1] CAO X Q,VASSEN R,FISCHER W,et al.Lanthanum-ce-rium oxide as a thermal barrier-coating material for high-tem-perature applications [J].Advanced Materials,2003,15(17):1438-1442.
[2] ZHENG L,GUO H B,GUO L,et al.New generation ther-mal barrier coatings for ultrahigh temperature applications[J].Journal of Aeronautical Materials,2012,32(32):14-24.
[3] 韩玉君,叶福兴,王志平,等.热障涂层材料的研究进展 [J].材料保护,2011,44(3):50-53.HAN Y J,YE F X,WANG Z P,et al.Research progress of thermal barrier coating materials [J].Materials Protection,2011,44(3):50-53(in Chinese).
[4] 陈和兴,金展鹏,周克崧.等离子喷涂热障涂层失效机理的研究[J].广东有色金属学报,2002,12(2):116-119.CHEN H X,JIN Z P,ZHOU K S.Study on failure mecha-nism of plasma sprayed thermal barrier coating[J].Journal of Guangdong Non-Ferrous Metals,2002,12(2):116-119(in Chinese).
[5] LI G R,XIE H,YANG G J,et al.A comprehensive sinte-ring mechanism for TBCs-part Ⅰ:An overall evolution with two-tage kinetics[J].Journal of the American Ceramic Soci-ety,2017,100(5):2176-2189.
[6] LI G R,XIE H,YANG G J,et al.A comprehensive sinte-ring mechanism for TBCs-part Ⅱ:Multiscale multipoint in-terconnection enhanced initial kinetics[J].Journal of the A-merican Ceramic Society,2017,100(9):4240-4251.
[7] LI G R,YANG G J,Li C X,et al.A comprehensive sinte-ring mechanism for TBCs-part Ⅲ:Substrate constraint effect on healing of 2D pores[J].Journal of the American Ceramic Society,2018,101(8):3636-3648.
[8] HUANG J,WANG W,YU J,et al.Effect of particle size on the micro-cracking of plasma-sprayed YSZ coatings during thermal cycle testing[J].Journal of Thermal Spray Technolo-gy,2017,26:1-9.
[9] ZHONG X,ZHAO H,ZHOU X,et al.Thermal shock be-havior of toughened gadolinium zirconate/YSZ double-ceram-ic-layered thermal barrier coating [J].Journal of Alloys & Compounds,2014,593(593):50-55.
[10] DENG W,AN Y L,HOU G,et al.Effect of substrate pre-heating treatment on the microstructure and ultrasonic cavita-tion erosion behavior of plasma-sprayed YSZ coatings [J].Ultrasonics Sonochemistry,2018,46:1-9.
[11] 叶福兴,吕雁兵,郝利军,等.QT500 表面化学镀镍磷层对8YSZ热障涂层抗热震性能的影响[J].天津大学学报:自然科学与工程技术版,2016,49(1):15-20.YE H X,LV Y B,HAO L J,et al.Influence of chemical ni-p plating on thermal shock resistance of 8YSZ thermal barrier coatings on QT500 substrate[J].Journal of Tianjin Universi-ty(Science and Technology),2016,49(1):15-20(in Chinese).
[12] LLAVSKY J,STALICK J K.Phase composition and its changes during annealing of plasma-sprayed YSZ[J].Sur-face & Coatings Technology,2000,127(2-3):120-129.
[13] 张巍.氧化锆基陶瓷热障涂层的研究进展[J].航空工程进展,2018,9(4):18-36.ZHANG W.Progress on zirconia-based ceramics for thermal barrier coatings[J].Advances in Aeronautical Science and Engineering,2018,9(4):18-36(in Chinese).
[14] JING F,REN X,WANG X,et al.Thermal conductivity of ytterbia-stabilized zirconia[J].Scripta Materialia,2012,66(1):41-44.
[15] OCHROMBEL R,SCHNEIDER J,HILDMANN B,et al.Thermal expansion of EB-PVD yttria stabilized zirconia[J].Journal of the European Ceramic Society,2010,30(12):2491-2496.
[16] 吴秀刚,李晨希.大气等离子喷涂热障涂层的失效机理及研究进展[J].材料保护,2013,46(10):48-51.WU X G,LI C X.Failure mechanism and research progress of atmospheric plasma sprayed thermal barrier coatings[J].Materials Protection,2013,46(10):48-51(in Chinese).
[17] REN X,ZHAO M,FENG J,et al.Phase transformation be-havior in air plasma sprayed yttria stabilized zirconia coating [J].Journal of Alloys & Compounds,2018,750:189-196.
[18] 薛召露,郭洪波,宫声凯,等.新型热障涂层陶瓷隔热层材料[J].航空材料学报,2018,38(2):10-20.XUE Z L,GUO H B,GONG S K,et al.New thermal barri-er coating ceramic insulation material[J].Journal of Aero-nautical Materials,2018,38(2):10-20(in Chinese).
[19] VASSEN R,CAO X Q,TIETZ F,et al.Zirconates as new materials for thermal barrier coatings[J].Journal of the A-merican Ceramic Society,2000,83(8):2023-2028.
[20] ZHAO M,PAN W,WAN C L,et al.Defect engineering in development of low thermal conductivity materials:A review [J].Journal of the European Ceramic Society,2017,37(1):1-13.
[21] BAKAN E,VASSEN R.Ceramic top coats of plasma-sprayed thermal barrier coatings:materials,processes,and properties [J].Journal of Thermal Spray Technology,2017,26(6):992-1010.
[22] WANG C J,WANG Y,CHENG Y L,et al.Preparation and thermophysical properties of nano-sized Ln2Zr2O7(Ln = La,Nd,Sm,and Gd)ceramics with pyrochlore structure[J].Journal of Materials Science,2012,47(10):4392-4399.
[23] 王铀,王亮.新型锆酸盐基热障涂层材料的研究进展 [J].中国表面工程,2009,22(6):8-18.WANG Y,WANG L.Research progress of new types of zir-conate-based thermal barrier coatings[J].China Surface En-gineering,2009,22(6):8-18(in Chinese).
[24] 牟仁德,许振华,贺世美,等.La2(Zr0.7Ce0.3)2O7-新型高温热障涂层[J].材料工程,2009(7):67-71.MOU R D,XUE Z H,HE S M,et al.La-2(Zr0.7Ce0.3)2O7-A new oxide ceramic material for thermal barrier coatings [J].Journal of Materials Engineering,2009(7):67-71(in Chinese).
[25] KONG L G,KARATCHEVTSEVA I,GREGG D J,et al.A novel chemical route to prepareLn2Zr2O7pyrochlore [J].Journal of the American Ceramic Society,2013,96(3):935-941.
[26] NAGA S M,AWAAD M,EL-MAGHRABY H F,et al.Effect of La2Zr2O7 coat on the hot corrosion of multi-layer thermal barrier coatings [J].Materials & Design,2016,102:1-7.
[27] SIVAKUMAR S,PRAVEEN K,SHANMUGAVEL-AYUTHAM G.Preparation and thermophysical properties of plasma sprayed lanthanum zirconate[J].Materials Chemistry and Physics,2018,204:67-71.
[28] ZHANG J,GUO X Y,JUNG Y G,et al.Lanthanum zirco-nate based thermal barrier coatings:A review[J].Surface &Coatings Technology,2017,323:18-29.
[29] LIU T,CHEN X,YANG G J,et al.Properties evolution of plasma-sprayedLn2Zr2O7coating induced by pore structureevolution during thermal exposure[J].Ceramics Internation-al,2016,42(14):15485-15492.
[30] YANG G J,CHEN Z L,LI C X,et al.Microstructural and mechanical property evolutions of plasma-sprayed YSZ coat-ing during high-temperature exposure:Comparison study be-tween 8YSZ and 20YSZ[J].Journal of Thermal Spray Tech-nology,2013,22(8):1294-1302.
[31] MARSHALL D B,NOMA T,EVANS A G.A simple method for determining elastic-modulus-to-hardness ratios using knoop indentation measurements[J].Journal of the Ameri-can Ceramic Society,1982,65(10):C175-C176.
[32] LI G R,YANG G J,LI C X,et al.Sintering characteristics of plasma-sprayed TBCs:Experimental analysis and an over-all modelling [J].Ceramics International,2018,44(3):2982-2990.
[33] ZHOU Y C,HASHIDA T.Coupled effects of temperature gradient and oxidation on thermal stress in thermal barrier coating system[J].International Journal of Solids and Struc-tures,2001,38(24-25):4235-4264.
[34] CHENG B,YANG G J,ZHANG Q,et al.Gradient thermal cyclic behaviour ofLn2Zr2O7/YSZ DCL-TBCs with equiva-lent thermal insulation performance[J].Journal of the Euro-pean Ceramic Society,2018,38(4):1888-1896.
[35] ZHANG J,GUO X Y,JUNG Y G,et al.Lanthanum zirco-nate based thermal barrier coatings:A review[J].Surface & Coatings Technology,2017,323:18-29.
[36] WU Q,JI X J,PENG H R,et al.Phase stability of ce-mod-ifiedLn2Zr2O7coatings and chemical compatibility with YSZ [J].Journal of Thermal Spray Technology,2016,25(4):757-762.
[37] CLYNE T W,GILL S C.Residual stresses in thermal spray coatings and their effect on interfacial adhesion:A review of recent work [J].Journal of Thermal Spray Technology,1996,5(4):401-418.
[38] 陈林,杨冠军,李成新,等.热喷涂陶瓷涂层的耐磨应用及涂层结构调控方法[J].现代技术陶瓷,2016(1):3-21.CHEN L,YANG G J,LI C X,et al.Wear-resisting applica-tion of thermal spray ceramic coating and coating structure control method[J].Advanced Ceramics,2016(1):3-21(in Chinese).
[39] LI C J,OHMORI A.Relationships between the microstruc-ture and properties of thermally sprayed deposits[J].Journal of Thermal Spray Technology,2002,11(3):365-374.
[40] MCPHERSON R.A review of microstructure and properties of plasma sprayed ceramic coatings[J].Surface & Coatings Technology,1989,39(89):173-181.
[41] KUCZYNSKI G C.Self-diffusion in sintering of metallic par-ticles[J].Transactions of the American Institute of Mining and Metallurgical Engineers,1949,185(2):169-178.
[42] 李广荣,杨冠军.热障涂层高温跨尺度服役机理及多维度结构设计[J].现代技术陶瓷,2018,39(5):29-62.LI G R,YANG G J.High-temperature cross-scale service mechanism and multi-dimensional structural design of thermal barrier coatings [J].Advanced Ceramics,2018,39(5):29-62.(in Chinese).
[43] ERK K A,DESCHASEAUX C,TRICE R W.Grain-bounda-ry grooving of plasma-sprayed yttria-stabilized zirconia ther-mal barrier coatings [J].Journal of the American Ceramic Society,2006,89(5):1673-1678.
[44] TSIPAS S A,GOLOSNOY I O,DAMANI R,et al.The effect of a high thermal gradient on sintering and stiffening in the top coat of a thermal barrier coating system[J].Journal of Thermal Spray Technology,2004,13(3):370-376.
PDF(13993 KB)

32

Accesses

0

Citation

Detail

段落导航
相关文章

/