杂质对氧化锆热障涂层性能的影响

doi:10.15541/jim20200078

摘要/Abstract

摘要：

降低热障涂层面层中的低熔点杂质含量, 可提高涂层的高温稳定性和延长服役寿命。SiO₂、Al₂O₃和Fe₂O₃是氧化钇稳定氧化锆(Yttria-Stabilized Zirconia, YSZ)热障涂层中几种常见的低熔点氧化物杂质, 均会对涂层的性能产生一定的影响。本研究采用大气等离子喷涂法, 制备SiO₂、Al₂O₃和Fe₂O₃的含量从小于0.01wt%增加至1.00wt%的YSZ热障涂层。采用扫描电镜(SEM)和透射电镜(TEM)研究了上述涂层的微观结构; 采用激光热导仪测试了涂层的热扩散系数和抗热震次数。研究结果表明, 低熔点氧化物杂质对YSZ涂层的导热性、热处理状态的孔隙率具有明显影响, 且更容易引起涂层的热震失效。当杂质氧化物含量在小于0.2wt%范围内变化时, 涂层的性能变化更为显著。

关键词: 热障涂层, 杂质, YSZ, 抗热震性能, 导热性

Abstract:

Reducing low-melting impurity content in thermal barrier coatings (TBCs) can improve the high temperature stability and service life of coatings. But there is rare quantitative study on the relationship between the low-melting impurity content and coating properties. In the present work, the effect of SiO₂, Al₂O₃, and Fe₂O₃ impurities on the properties of Yttria-Stabilized Zirconia (YSZ) TBCs prepared by atmospheric plasma spraying was investigated. The samples were prepared with the contents of these impurities being increased gradually from less than 0.01wt% to 1.00wt%. The results demonstrated that those low-melting oxide impurities exhibit a significant effect on thermal conductivity and porosity of the coatings, playing a key role on thermal shock failure. The performance of coatings deteriorated especially significantly when the impurity oxide content is less than 0.2wt%.

Key words: thermal barrier coating, impurity, YSZ, thermal shock resistance, thermal conductivity

中图分类号:

TG174

冀晓鹃,于月光,卢晓亮. 杂质对氧化锆热障涂层性能的影响[J]. 无机材料学报, 2020, 35(6): 669-674.

JI Xiaojuan,YU Yueguang,LU Xiaoliang. Effects of Impurities on Properties of YSZ Thermal Barrier Coatings[J]. Journal of Inorganic Materials, 2020, 35(6): 669-674.

图/表 11

表1 YSZ原料的化学成分(wt%)

Table 1 Chemical composition of YSZ raw materials (wt%)

ZrO₂	HfO₂	TiO₂	SiO₂	MgO	Fe₂O₃
90.28	1.55	<0.01	<0.01	<0.01	<0.01
Y₂O₃	Al₂O₃	CaO	Na₂O	K₂O
7.92	0.011	<0.01	<0.01	<0.01

表2 YSZ喷涂粉末的设计成分(D)及涂层的实测成分(M)(wt%)

Table 2 Design composition (D) of YSZ powders and measured composition (M) of YSZ coatings (wt%)

No.	SiO₂		No.	Al₂O₃		No.	Fe₂O₃
No.	D	M	No.	D	M	No.	D	M
HP	<0.01	<0.01	—	<0.01	<0.01	—	<0.01	0.0049
S1	0.02	0.013	A1	0.02	0.014	F1	0.02	0.0140
S2	0.06	0.038	A2	0.06	0.030	F2	0.06	0.0390
S3	0.10	0.064	A3	0.10	0.051	F3	0.10	0.0800
S4	0.16	0.110	A4	0.15	0.079	F4	0.16	0.1100
S5	0.20	0.150	A5	0.20	0.120	F5	0.20	0.1400
S6	0.36	0.260	A6	0.35	0.230	F6	0.36	0.3000
S7	0.50	0.320	A7	0.50	0.300	F7	0.50	0.3400
S8	0.66	0.430	A8	0.65	0.380	F8	0.66	0.4600
S9	0.80	0.550	A9	0.80	0.450	F9	0.80	0.5700
S10	1.00	0.620	A10	1.00	0.640	F10	1.00	0.5900

表3 HVOF喷涂工艺参数

Table 3 Parameters of HVOF process

Coal oil /(L·h^-1)	O₂/(L·min^-1)	Ar (Carrier gas) /(L·min^-1)	Powder feeding rate/(g·min^-1)	Distance/ mm
26	900	8	75	380

表4 APS喷涂工艺参数

Table 4 Parameters of APS process

Current/A	Voltage/V	Power/kW	Distance/mm
620	76	47	100
Ar/(L·min^-1)	H₂/(L·min^-1)	Ar(Carrier gas)/ (L·min^-1)	Powder feeding rate/(g·min^-1)
38	13	4.5	30

图1 S1双层热障涂层的显微形貌

Fig. 1 Microstructure of S1 two-layer thermal barrier coaing

图2 1400 ℃热处理100 h后YSZ涂层的孔隙率

Fig. 2 Porosities of YSZ coatings heat-treated at 1400 ℃ for 100 h

图3 不同热处理条件下含1wt%氧化物YSZ涂层的孔隙率

Fig. 3 Porosities of YSZ coatings doped with 1wt% oxides after heat treatment

图4 YSZ涂层的热扩散系数

Fig. 4 Thermal diffusivity of YSZ coatings

图5 YSZ涂层的热震寿命

Fig. 5 Thermal shock lifetime of YSZ coatings

图6 含1wt% SiO2YSZ涂层的(a)喷涂态及(b)经1400 ℃热处理10 h后的TEM照片及衍射斑点

Fig. 6 TEM microstructures and diffraction spots of YSZ coatings doped with 1wt% SiO2 (a) As-sprayed; (b) After heat- treatment at 1400 ℃ for 10 h

图7 含1wt% Al2O3的YSZ涂层的(a)喷涂态及(b)经1400 ℃热处理10 h后的TEM照片及衍射斑点

Fig. 7 TEM microstructure and diffraction spots of YSZ coatings doped with 1wt% Al2O3 (a) As-sprayed; (b) After heat- treatment at 1400 ℃ for 10 h

参考文献 30

[1]	DAROLIA R . Thermal barrier coatings technology: critical review, progress update, remaining challenges and prospects. International Materials Reviews, 2013,58(6):315-348. DOI URL
[2]	CURRY N, MARKOCSAN N, LI X H , et al. Next generation thermal barrier coatings for the gas turbine industry. Journal of Thermal Spray Technology, 2011,20(1/2):108-115.
[3]	STӦVER D, PRACHT G, LEHMANN H , et al. New material concepts for the next generation of plasma-sprayed thermal barrier coatings. Journal of Thermal Spray Technology, 2004,13(1):76-83.
[4]	XUE Z L, GUO H B, GONG S K , et al. Novel ceramic materials for thermal barrier coatings. Journal of Aeronautical Materials, 2018,38(2):10-20.
[5]	CURRY N, JANIKOWSKI W, PALA Z , et al. Impact of impurity content on the sintering resistance and phase stability of dysprosia- and yttria-stabilized zirconia thermal barrier coatings. Journal of Thermal Spray Technology, 2014,23(1/2):160-169.
[6]	LYU G, CHOI B G, LU Z , et al. Effect of thermal cycling frequency on the durability of Yb-Gd-Y-based thermal barrier coatings. Surface & Coatings Technology, 2019,364:187-195.
[7]	GORAL M, KOTOWSKI S, NOWOTNIK A , et al. PS-PVD deposition of thermal barrier coatings. Surface & Coatings Technology, 2013,237:51-55.
[8]	ŁATKA L . Thermal barrier coatings manufactured by suspension plasma spraying- a review. Advances in Materials Science, 2018,18(3):95-117.
[9]	JONNALAGADDA K P, ERIKSSON R, LI X H , et al. Thermal barrier coatings: life model development and validation. Surface & Coatings Technology, 2019,362:293-301.
[10]	PARK H M, JUN S H, LYU G , et al. Thermal durability of thermal barrier coatings in furnace cyclic thermal fatigue test: effects of purity and monoclinic phase in feedstock powder. Journal of the Korean Ceramic Society, 2018,55(6):608-617.
[11]	KARLSSON A M . Modeling failures of thermal barrier coatings. Key Engineering Materials, 2007,333:155-166.
[12]	HUA J J, ZHANG L P, LIU Z W , et al. Progress of research on the failure mechanism of thermal barrier coatings. Journal of Inorganic Materials, 2012,27(7):681-686.
[13]	MATSUI K . Sintering kinetics at constant rates of heating: mechanism of silica-enhanced sintering of fine zirconia powder. Journal of the American Ceramic Society, 2008,91(8):2534-2539.
[14]	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. Journal of Thermal Spray Technology, 2004,13(3):370-376.
[15]	CHOI S R, ZHU D M, MILLER R A . Effect of sintering on mechanical properties of plasma-sprayed zirconia-based thermal barrier coatings. Journal of the American Ceramic Society, 2005,88(10):2859-2867.
[16]	VAβEN R, CZECH N, MALLÉNER W , et al. Influence of impurity content and porosity of plasma-sprayed yttria-stabilized zirconia layers on the sintering behaviour. Surface and Coatings Technology, 2001,141:135-140.
[17]	PAUL S, CIPITRIA A, GOLOSNOY I O , et al. Effects of impurity content on the sintering characteristics of plasma-sprayed zirconia. Journal of Thermal Spray Technology, 2007,16(5/6):798-803.
[18]	XIE L, DORFMAN M R, CIPITRIA A , et al. Properties and performance of high-purity thermal barrier coatings. Journal of Thermal Spray Technology, 2007,16(5/6):804-808. DOI URL
[19]	HELMINIAK M A, YANAR N M, PETTIT F S , et al. The behavior of high-purity, low-density air plasma sprayed thermal barrier coatings. Surface & Coatings Technology, 2009,204:793-796.
[20]	MARKOCSAN N, NYLÉN P, WIGREN J, et al. Low thermal conductivity coatings for gas turbine applications. Journal of Thermal Spray Technology, 2007,16(4):498-505.
[21]	ZHU D M, MILLER R A . Development of advanced low conductivity thermal barrier coatings. International Journal of Applied Ceramic Technology, 2004,1(1):86-94.
[22]	WANG L, WANG Y, SUN X G , et al. Influence of pores on the thermal insulation behavior of thermal barrier coatings prepared by atmospheric plasma spray. Materials and Design, 2011,32:36-47.
[23]	ZHU D M, MILLER R A . Thermal conductivity and elastic modulus evolution of thermal barrier coatings under high heat flux conditions. Journal of Thermal Spray Technology, 2000,9(2):175-180.
[24]	ZHU D M, MILLER R A, NAGARAJ B A , et al. Thermal conductivity of EB-PVD thermal barrier coatings evaluated by a steady- state laser heat flux technique. Surface and Coatings Technology, 2001,138:1-8.
[25]	LI Y J, YU Y G, JI X J , et al. Effects of Al₂O₃ content on properties of YSZ thermal barrier coatings. Thermal Spray Technology, 2018,10(1):61-67.
[26]	GREMILLARD L, EPICIER T, CHEVALIER J , et al. Microstructural stucy of silica-doped zirconia ceramics. Acta Materialia, 2000,48:4647-4652.
[27]	HODGSON S N B, CAWLEY J, CLUBLEY M . The role of SiO₂ impurities in the microstructure and properties of Y-TZP. Journal of Materials Processing Technology, 1999,86:139-145.
[28]	MATSUI K, YOSHIDA H, IKUHARA Y . Phase-transformation and grain-growth kinetics in yttria-stabilized tetragonal zirconia polycrystal doped with a small amount of alumina. Journal of the European Ceramic Society, 2010,30:1679-1690.
[29]	SAKKA Y, ISHII T, SUZUKI T S , et al. Fabrication of high-strain rate superplastic yttria-doped zirconia polycrystals by adding manganese and aluminum oxides. Journal of the European Ceramic Society, 2004,24:449-453.
[30]	WU S X, BROOK R J . Kinetics of densification in stabilized zirconia. Solid State Ionics, 1984,14:123-130. DOI URL