采用固相合成制备了热障涂层陶瓷材料La2（Zr0.7Ce0.3）2O7（LZ7C3）。通过差热分析、X射线衍射等分析方法对固相合成行为影响因素进行研究,并用激光脉冲法和高温膨胀仪测试了LZ7C3粉末的热扩散系数和热膨胀系数。结果表明：完全合成LZ7C3的温度至少1400℃,煅烧时间至少5 h,反应粉末的粒度为0.82μm时,合成的LZ7C3粉末X射线衍射图谱没有La2 O3残留峰,其La∶Zr∶Ce为50.09∶35.12∶14.79,非常接近理论原子比例10∶7∶3;LZ7C3的热导率在1200℃时为0.79 W.m-1.K-1,热膨胀系数在1200℃时为11.6×10-6K-1,从室温到1200℃的加热过程中没有失重和相变发生,具有较高的相稳定性。
La2(Zr0.7Ce0.3)2O7(LZ7C3) ceramics used for thermal barrier coating were prepared by solid reaction synthesis,the factors influencing the synthesis were studied by TG-DTA and XRD,and the thermal diffusivity and thermal expansion coefficient of LZ7C3 ceramics were determined with a laser flash apparatus and a high-temperature dilatometer.The results show that the lowest synthesis temperature and time for the preparation of LZ7C3 ceramics are 1400 ℃ and 5 h,respectively.There are no unreacted La2O3 peaks in the XRD pattern of prepared powders when the raw powders granularity is 0.82 μm in the solid synthesis process,and their atom ratio(La∶Zr∶Ce) is very close to 10∶7∶3 which is the theory value of LZ7C3.The thermal conductivity of LZ7C3 is 0.79 W·m-1·K-1 at 1200 ℃,whereas its thermal expansion coefficient is 11.6×10-6 K-1at 1200 ℃.The prepared LZ7C3 ceramics has high stability in the heating process from ambient temperature to 1200 ℃.
参考文献
| [1] | Sohn Y H;Lee E Y;Nagaraj B A et al.Microstructure characterization of themal barrier coatings on high presser turbine blades[J].Surface and Coatings Technology,2001,146-147:132-139. |
| [2] | Miller R A .Thermal barrier coatings for aircraft engines:history and directions[J].Journal of Thermal Spray Technology,1997,6(01):35-42. |
| [3] | Nitin P. Padture;Maurice Gell;Eric H. Jordan .Thermal Barrier Coatings for Gas-Turbine Engine Applications[J].Science,2002(5566):280-284. |
| [4] | Cao X Q;Vassen R;Stoever D .Ceramic materials for thermal barrier coatings[J].Journal of the European Ceramic Society,2004,24(01):1-10. |
| [5] | Zhan-Guo Liu;Jia-Hu Ouyang;Yu Zhou .Influence of ytterbium- and samarium-oxides codoping on structure and thermal conductivity of zirconate ceramics[J].Journal of the European Ceramic Society,2009(4):647-652. |
| [6] | Xu Q;Pan W;Wang J et al.Preparation and thermophysical properties of Dy2 Zr2 07 ceramic for thermal barrier coatings[J].Materials Letters,2005,59:2804-2807. |
| [7] | Winter M R;Clarke D R .Oxide materials with low thermal conductivity[J].Acta Materialia,2006,54:5051-5059. |
| [8] | Xueqiang Cao;Robert Vassen;Werner Fischer;Frank Tietz;Wolfgang Jungen;Detlev Stover .Lanthanum-Cerium Oxide as a Thermal Barrier-Coating Material for High-Temperature Applications[J].Advanced Materials,2003(17):1438-1442. |
| [9] | 周宏明,易丹青,钟华.稀土Dy和Ce共掺杂La2Zr2O7新型热障涂层用陶瓷材料[J].无机材料学报,2008(03):567-572. |
| [10] | Xueqiang CAO.Application of Rare Earths in Thermal Barrier Coating Materials[J].材料科学技术学报（英文版）,2007(01):插2-35. |
| [11] | X. Q. CAO;R. VASSEN;F. TIETZ .New double-ceramic-layer thermal barrier coatings based on zirconia-rare earth composite oxides[J].Journal of the European Ceramic Society,2006(3):247-251. |
| [12] | Cao X Q;Li J Y et al.La2( Zr0.7 Ceo.3 )2 O7-A new oxide ceramic material with high sintering resistance[J].Materials Letters,2008,62:2667-2669. |
| [13] | Narottam P. Bansal;Dongming Zhu .Effects of doping on thermal conductivity of pyrochlore oxides for advanced thermal barrier coatings[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2007(1/2):192-195. |
| [14] | Zhenhua Xu;Limin He;Xinghua Zhong .Thermal barrier coating of lanthanum-zirconium-cerium composite oxide made by electron beam-physical vapor deposition[J].Journal of Alloys and Compounds,2009(1/2):168-172. |
| [15] | ZHOU Hongming,YI Danqing.Effect of rare earth doping on thermo-physical properties of lanthanum zirconate ceramic for thermal barrier coatings[J].稀土学报（英文版）,2008(06):770-774. |
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