摘要
ZrO_2具有低的热导率和与高温合金相近的热膨胀系数,是制备高温下使用的热障涂层的理想材料。Y_2O_3用来稳定ZrO_2中的四方相,减少ZrO_2高低温使用时相转变产生的大的体积变化,从而降低裂纹产生的可能性。热等离子体喷涂是制备热障涂层的最主要办法。常规微米级陶瓷涂层脆性大,而纳米陶瓷脆性降低。液相法制备出来的ZrO_2/Y_2O_3纳米粉末由于单个粒子质量太小,不能直接用来进行热喷涂。
本项研究的目的就是制备ZrO_2-8%Y_2O_3大颗粒球形纳米粉末和热障涂层,且使其可以保持原始粉末的纳米结构。首先采用喷雾干燥和热处理的办法对原始ZrO_2-8%Y_2O_3纳米粉末进行再处理,然后将经过再处理的纳米粉末在不同的等离子体喷涂条件下喷涂制备成纳米结构热障涂层。利用光学显微镜和扫描电镜分析粉末粒径大小、颗粒形貌、涂层显微组织,用X-ray衍射分析原始粉末、再处理粉末和涂层的相组成,用热重-差热分析仪对纳米团聚体粉末进行热分析,并测量粉末的松装密度、振实密度及流动性。结果表明:ZrO_2-8%Y_2O_3原始纳米粉末经过再处理后近似球形,粒径在10-100μm之间,仍为纳米结构。粉末流动性好、振实密度高,可以用来热喷涂制备纳米结构热障涂层。采用再处理的纳米粉末进行等离子体喷涂制备的涂层厚度均匀,没有明显的层状结构。等离子体喷涂制备涂层的过程中发生了单斜相向四方相的转变,涂层中只有四方相和立方相存在。这种热障涂层是一种纳米-微米结构复合涂层。
Zirconia has low thermal conductivity and high thermal expansion coefficient close to nickel-based superalloy substrate. It is an ideal material used as thermal barrier coatings applicable to high temperatures. Plasma spraying is the most often used method for depositing thermal barrier coatings. Conventional ceramic coatings, consisted of micro-lamellae, are brittle. However, nanostructured ceramic materials have low brittleness and improved toughness. ZrO2/Y2O3 nanocrystalline powder, prepared by the method of solution precipitation, can not be directly used as thermal spray feed stock, because of its low mass of individual nanocrystalline particle.
This study was to prepare ZrO2-8%Y2O3 agglomerated nanocrystalline particles and to form nanostructured thermal barrier coatings by plasma spraying under varied conditions. Spray drying and heat treatment were used to reprocess the nanocrystalline ZrO2-8%Y2O3 powder purchased from market. Optical microscopy and scanning electron microscopy were used to observe the morphology and particle size of the starting nanocrystalline powder and the agglomerated powder as well as to examine the microstructure of the thermal barrier coatings. X-ray diffraction was used to analyze the crystal structure of the powders and the coatings. Thermal gravimetric analysis and diffraction thermal analysis were also conducted. In addition, free holding density, tap density, and flow ability of the powders were measured. Experimental results show that the large agglomerated particles are spheric, have the size of 10-100um, and remain original nanostructure. Such powders with good flow ability and high tap density are suitable for th
ermal spray used in the deposition of nanostructured thermal barrier coatings. Experimental results of the thermal barrier coatings deposited from the agglomerated nanocrystalline powders with different particle size distributions (<45um and 45~75um) demonstrate that the thickness of the as-sprayed coatings is uniform, and the lamellae always found in conventional microstructured coatings are not obvious in these nanostructured coatings. The porosity of the best coating sample is approximately 7%. The
HI
monoclinic zirconia phase existed in the starting powder has been transformed into tetragonal phase after the plasma spraying. The nanostructured coatings are composed of tetragonal and cubic phases. It is revealed that these coatings consist of a large fraction of nanostructure transformed from unmelted agglomerates and a mall fraction of microstructure formed from melted agglomerates in plasma.
引文
[1] W. Belle, G. Marijnissen. and A. Van Lieshout, "The evolution of thermal barrier coatings status and upcoming solutions for today's key issues", Surface and Coatings Technology, 120-121(1999), P: 61-67
[2] F. Jamarani, M. Korothkin, R. W. Lang, M. F. Ouellette, K. L. Yan and R.W. Bertram, "Compositionally graded thermal barrier coatings for high temperature aerogas turbine components", Surface and Coatings Technology, 54-55(1992), P: 58-63
[3] C. Meterns Lecomte, D. Muok, and J. Garcia, "Characterization of a new aerospace thermal barrier coatings", Proceedings of the 7th National thermal spray conference, 20-24(1994), Boston, P: 61-65
[4] K. Ebert, C. verpoort, Langenfeld, "Production and application of thermally spray ceramic layers", cfi/Ber. DKG, 77(2000), P: E11-El4
[5] H. Xu, H. Gao, F. Liu, and S. Gong, "Development of gradient thermal barrier coatings and their hot-fatigue behavior". Surface and Coatings Technology, 130(2000),P: 133-139
[6] P. D. Harmsworth, R. Stevens, "Microstructure of zirconia-yttria plasma -sprayed thermal barrier coatings", Journal of Materials Science, 27(1992), P: 616-624
[7] R. Chaim, M. Ruhle, A. H. Heuer, "Microstructural evolution in a ZrO_2-12wt%Y_2O_3 ceramic", Journal Of the American Ceramic Society, 68(1985), P: 427-431
[8] A. Rabid, A. G. Evans, "Failure mechanisms associated with the thermally grown oxide in plasma sprayed thermal barrier coatings", Acta Materialia, 48(2000), P: 3963-3976
[9] M. Gell, "Application opportunities for nanostructured materials and coatings", Materials Science and Engineering A, 204(1995), P: 246-251
[10] B. H. Kear, Ganesh Skandan, "Overview: status and current developments in nanomaterials", The International Journal of Powder Metallurgy, 35(1999), P: 246-251
[11] N. Rittner Mindy, Abraham Thomas, "Nanostructured materials: An overview and commercial analysis". JOM, January 1998, P: 36-37
[12] Yulin Lu, K. Liaw Peter, "The mechanical properties of nanostructured materials", JOM, March 2001, P: 31-35
[13] K. A. Padmanabhan, "Mechanical properties of nanostructured materials",Materials Science and Engineering A, 304-306(2001), P: 200-205
[14] M. Gell, "Applying nanostructured materials to future gas turbine engines", JOM,October 1994, P: 30-34
[15] X. L. Jiang, "Overview on the processing, structure, and properties of nanocrystalline materials", International Conference On Surface and Interface Science and Engineering, 2001, shenzhen, china
[16] 蒋显亮, “纳米材料的回顾与展望”,功能材料增刊,2001.10,P:1238-1240
[17] C. Albin, P. Lech, and N. Blanchard, "Injection of hot particles in the plasma flame", Journal of Thermal Spray Technology, 9(2000), P458-462
[18] P. Fauchais, A. Vardelle, and B. Dussoubs, "Quovadis thermal spraying", Journal of Thermal Spray Technology, 10(2001), P: 44-66
[19] J. Mostaghimi and S. Chandra, "Splat formation in plasma spray coating process", Pure and Applied Chemistry, 74(2002), P: 441-445.
[20] R. S. Lima, A. Kucuk, U. Senturk, and C. C. Berndt, "Properties and microstructures of nanostructured partially stabilized zirconia coatings", Journal of Thermal Spray Technology Extended Abstracts, 10(2001 ), P: 150-152
[21] E. P. Busso, J. Lin, S. Sakurai, and M. Nakayama, "A mechanistic study of oxidation induced degradation in a plasma sprayed thermal barrier coating system. Part1:model formulation", Acta Materialia, 49(2001), P: 1515-1528
[22] 周玉,雷廷权,陶瓷材料学,哈尔滨工业大学出版社,1995
[23] 卢旭晨,“ZrO_2粉料喷雾造粒子的形貌、显微结构及其成型性能”,硅酸盐学报,25(1997),P:364-367
[24] 谭强,“氧化锆空心球粉中试生产及应用技术研究”,功能材料,10(2001)增刊,P:1620-1624
[25] 王零森,特种陶瓷,中南工业大学出版社,2000
[26] P. G. Klemens, M. Gell, "Thermal conductivity of thermal barrier coatings",Materials' Science and Engineering A, 245(1998), P: 143-149
[27] C. J. Howard, R. J. Hill, "The polymorphs of zirconia: phase abundance and crystal structure by Riveted analysis of neutron and X-ray diffraction data", Journal of materials Science, 26(1991), P: 127-134
[28] J. Katamura and T. Sakuma, "Thermodynamic analysis of the cubic tetragonal phase equilibria in the system ZrO_2-YO_1.5", Journal of the American Ceramic Society, 80(1997), P: 2685-2688
[29] N. Shibata, J. Katamura, A. Kuwabara, Y. Ikuhara, T. Sakuma, "The instability and resulting phase transition of cubic zirconia", Materials Science and Engineering A, 312(2001), P: 90-98
[30] C. H. Lee, H. K. Kim, H. S. Choi, H. S. Ahm, "Phase transformation and bond coat oxidation behavior of plasma sprayed zirconia thermal barrier coating", Surface and Coatings Technology, 124(2000), P: 1-12
[31] J. Llavsky, K. Stalick Judith, and J. Wallace, "Thermal spray yttria-stabilized zirconia phase changes during annealing", Journal of Thermal Spray Technology, 10(2001), P: 497-501
[32] R. Vaben, N. Czech, W. Mallener, W. Stature, D. Stover, "Influence of impurity content and porosity of plasma sprayed yttria stabilized zirconia layers on the sintering behaviour", Surface and Coatings Technology, 141 (2001), P: 135-140
[33] R. Siegel, C. M. Spuckler, "Analysis of thermal radiation effects on temperatures in turbine engine thermal barrier coatings", Materials Science and Engineering A, 245(1998), P: 150-159
[34] R. McPherson, "A review of microstructure and properties of plasma sprayed ceramic coatings", Surface and Coatings Technology, 39-40(1989), P: 173-181
[35] M. Levit, I. Grimberg, B. Z. Weiss, " Residual stresses in ceramic plasma sprayed thermal barrier coatings: measurement and calculation", Materials Science and Engineering A, 206(1996), P: 30-38
[36] 理查德 J.布鲁克,陶瓷工艺,科学出版社,1999
[37] J. M. Ralph, A. C. Schoeler, M. Krumpelt, "Materials for lower temperature solid oxide fuel cells", Journal of Materials Science, 36(2001), P:1161-1172
[38] C. Friedrich, R. Gadow, and T. Schirmer, "Lanthanum hexaaluminate a new material for atmospheric plasma spraying of advanced thermal barrier coatings", Journal of Thermal Spray Technology, 10(2001), P: 592-597
[39] M. Lang, R. Henne, S. Schaper, and G. Schiller, "Development and characterization of vacuum plasma sprayed thin film solid oxide fuel cells", Journal of Thermal Spray Technology, 10(2001), P: 618-626
[40] J. Kraft, M. Alaya, B. Eigenmann, R. Oberacker, "Influence of particle size and residual stresses on the failure mechanisms of plasma sprayed ZrO_2 thermal barrier coatings", cfi/Ber.DKG, 77(2000), P: E34-E37
[41] E. P. Busso, J. Lin and S. Sakurai, "A mechanistic study of oxidation induced degradation in a plasma sprayed thermal barrier coating system. Part2: Life prediction model", Acta Materialia, 49(2001 ), P: 1529-1536
[42] R. W. Rigney, "Commercialization of thermal spray nanomaterials coatings: lessons learned, challenges, and future opportunities", Journal of Thermal Spray Technology Extended Abstracts, 10(1), March2001, P: 147-148
[43] E. Jordan and M. Gell, "Thermal spray of nanocrystalline ceramics: a program overview", Journal of Thermal Spray Extended A bstracts, 10(1),March2001, P: 148
[44] N. Padture, K. Schlichting, M. Gell, E. Jordan, and P. Klemens, "Thermal barrier coatings based on zirconia ceramics: nanostructure, microstructure, properties, and performance", Journal of Thermal Spray Technology Extended Abstracts, 10(2001), P:149-150
[45] L. L. Shaw, D. Goberman, R. Ren, M. Gell, S. Jiang, You Wang, T. D. Xiao, P. R. Strutt, et al, "The dependency of microstructure and properties of nanostructured coatings on plasma spray conditions", Surface and Coating Technology, 130(2000), P: 1-8
[46] Y. Wang, S. Jiang, M. Wang, S. Wang, T. D. Xiao, P. R. Strutt, "Abrasive wear characteristics of plasma sprayed nanostructured alumina/titania coatings", Wear, 237(2000), P: 176-185
[47] E. H. Jordan, M. Gell, Y. H. Sohn, D. Goberman, L. Shaw, S. Jiang, M. Wang, T. D. Xiao, Y. Wang, P. Strutt, "Fabrication and evaluation of plasma sprayed nanostructured alumina/titania coatings with superior properties", Materials and Engineering A, 301(2001), P: 80-89
[48] X. L. Jiang, E. H. Jordan, L. Shaw and M. Gell, "Plasma spray forming of nanostructured composite coatings", Journal of Materials Science and Technology,18(2002), P: 287-288
[49] T. D. Xiao, S. Jiang, Y. Wang, D. M Wang, and P. R. Strutt, "Thermal spray of nanostructured alumina/titania feedstock for improved properties", Journal of Thermal Spray Technology Extended Abstracts, 10(2001), P: 177-178
[50] R. S. Lima, A. Kucuk, U. Senturk, and C. C. Berndt, "Properties and microstructures of nanostructured alumina-13%titania +zirconia coatings", Journal of Thermal Spray Technology Extended Abstracts, 10(2001 ), P: 179-180
[51] X. L. Jiang, E. Jordan, L. Shaw, M. Gell, "Deformation mechanism of nanostructured ceramic coatings", Physicochemical Mechanics of Materials, 1(2003), P:1
[52] B. Preauchat, S. Drawin, "Isothermal and cycling properties of zirconia-based thermal barrier coatings by PECVD", Surf Coat. Technol. 146-147 (2001), P: 94-101.
[53] R. S. Lima, A. Kucuk, C. C. Berndt, "Integrity of nanostructured partially stabilized zirconia after plasma spray processing", Materials Science and Engineering A, 313(2001), P: 75-82
[54] R. S. Lima, A. Kucuk, C. C. Berndt, "Evaluation of microhardness and elastic modulus of thermally sprayed nanostructured zirconia coatings", Surface and Coatings Technology, 135(2001),P: 166-172
[55] M. Gell, E. H. Jordan, Y. H. Sohn, D. Goberman, L. Shaw, T. D. Xiao, "Development and implementation of plasma sprayed nanostructured ceramic coatings", Surface and Coatings Technology, 146-147(2001),P: 48-54
[56] P.R.Strutt,B.H.Kear,“用于热喷涂的纳米结构进料”,中国专利号:96191409
[57] R. L. Holtz, K. Sadananda, "Fatigue behavior of nanostructured and conventional coatings", Journal Thermal Spray Technology Extended Abstract, 10(2001), P: 169-170
[58] M. C. Shaw, D. B. Marshall, B. J. Dalgleish, M. S. Dadkhah, M. Y. He, and A. G.. Evans, Acta Metall. Mater., 12(1994), P: 4091-4099
[59] A. G. Evans and J. W. Hutchinson, Acta Metall. Mater., 43(1995), P: 2507-2530
[60] L. L. Shaw, "Processing nanostructured materials: an overview", JOM, December2000, P: 41-45
[61] E. Schilbe John, "Substrate alloy element diffusion in thermal barrier coatings", Surface and Coatings Technology, 133-134(2000), P: 35-39
[62] W. Beele, G. Marijnissen, A. Van Lieshout, "The evolution of thermal barrier coatings status and upcoming solutions for today's key issues", Surface and Coatings Technology, 120-121(1999), P: 61-67
[63] M. Levichkova, V. Mankow, N. Starbov, D. Karashanova, B. Mednikarow, K. Starbova, "Structure and properties of nanosized electron beam deposited zirconia thin films", Surface and Coatings" Technology, 141 (2001), P: 70-77
[64] K. Vaidyanathan, M. Gell, and E. Jordan, "Mechanisms of spatlation of electron beam physical vapor deposited thermal barrier coatings with and without platinum aluminide bond coat ridges", Surface and Coatings' Technology, 133-134(2000), P: 28-34
[65] U. Schulz, K. Fritscher, C. Leyens, "Two-source jumping beam evaporation for advanced EB-PVD TBC systems", Surface and Coatings Technology, 133-134(2000), P:40-48
[66] H. Chen, C. X. Ding, "Nanostructured zirconia coating prepared by atmospheric plasma spraying", Surface and Coatings Technology, 150 (2002), P: 31-36
[67] S. J. Lukasiewicz, "Spray-drying ceramic powders" Journal of the American Society, 72(1989), P: 617-624
[68] D. Stewart, "Thermal spray processing of nanoscale materials", Powder Metallurgy, 40(1997), P: 185-186
[69] V. Provenzano, L. K. Kurihara, J. Y. Ying, M. L. Panchula, G. Kim, "Alumina/Zirconia nanocomposite thermal barrier coatings", Journal of Thermal Spray Technology, 10(2001), P: 150
[70] "Method of manufacture of nanostructured feedstock", U.S. Patent 6025034, Feb. 15, 2000
[71] C. X. Ding, R. A. Zatorski, H. Herman, D. Ott, "Oxide powders for plasma spraying the relationship between powder characteristics and coating properties", International Conference On Metallurgical Coatings, San Diego, CA, U.S.A., April 9-13,1984
[72] T. Hejwowski, A. Wero nski, "The effect of thermal barrier coatings on diesel engine performance", Vacuum, 65 (2002), P: 427-432
[73] P. Bork, "Spray drying plants for manufacture of dustless powders a technical note",Journal of Thermal Spray Technology, 10(4), December 2001
[74] K. Masters, "Applying spray drying to ceramics", American Ceramic Society Bulletin, 73(1), January 1994, P: 63-72
[75] Yutaka Saito, Satoshi Tanaka, Nozomu Uchida, Keizo Uematsu, "Direct evidence for low—density regions in compacted spray-dried powders", Journal of the American Ceramic Society, 84(2001), P: 2454-2456
[76] G.D.Parfitt,细颗粒在液体介质中的分散,工业中的混合过程,中国石海化工出版社,1991,俞芷青,王英琛等译
[77] J. Karthikeyan, C. C. Berndt, J. Tikkanen, S. Reddy, H. Herman, "Plasma spray synthesis of nanomaterials powders and deposits", Materials' Science and Engineering A, 238(1997), P:274-286
[78] N. P. Padture, K. W. Schlichting, T. Bhatla, A. Ozturk, B. Cetegen, E. H. Jordan, M. Gell, S. Jiang, T. D. Xiao, P. R. Strutt, E. Garcia, P. Miranzo, and M. I. Osendi,
"Towards durable thermal barrier coatings with novel microstructures deposited by solution precursor plasma spray", Acta Materialia, 49(2001), P: 2251-2257
[79] P. Bagchi, R. D. Void, Journal Colloid Interface Science, 33(1979), P: 405-408
[80] 卢寿慈、宋少允,“微细颗粒在水中的分散”,武汉钢铁学院学报,14(1991),P:1-6
[81] 樊毅、王战宏、王零森,“ZrO_2亚微粉的搅动球磨研究”,功能材料,25(1994),P:258-262
[82] B. Preauchat, S. Drawin, "Properteis of PECVD-deposited thermal barrier coatings", Surf Coat. Technol. 142-144 (2001), P: 835-842.
[83] 陈彦灵、朱敏、齐民,“ZrO_2-20mol%CeO_2陶瓷粉末的高能球磨过程”,无机材料学报,9(1994),P:111-116
[84] Yi Fang, K. Dinesh, Agrawal, M. Roy Della, Roy Rustum, "Ultrasonic sieving of fine, dry powders", American Ceramic Society Bulletin, 74(1995), P:70-73
[85] H. S. Christopher, J. G. Victor, M. S. Rachelle, "Ultrasonic and mechanical behavior of green and partially sintered alumina: effects of slurry consolidation chemistry", Journal of the American Society, 81(1998), P: 2629-2639
[86] 卢寿慈,粉体加工技术,中国轻工业出版社,1999
[87] 蒋显亮,《表面与涂层技术》,2001年