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采用共沉淀技术制备了3种不同含量Ce改性的La2Zr2O7粉末(La2Zr2O7(LZ)、La2(Zr0.7Ce0.3)2O7(LZ7C3)、La2(Zr0.3Ce0.7)2O7(LZ3C7)),采用等离子喷涂制备了涂层,对涂层进行了1200和1300℃×100 h高温时效处理,采用扫描电镜、X射线衍射、透射电镜等方法对比观测了粉末相结构、纳米晶粒度、晶格常数,以及涂层的高温相结构演变和时效行为等。结果表明:LZ和LZ7C3粉末呈现单一烧绿石结构,LZ3C7呈现单一萤石结构,随着Ce掺杂量的增加,粉末晶格常数增加。3种涂层制备态均呈现为萤石结构,LZ和LZ7C3涂层经1200和1300℃×100 h高温时效后呈现为烧绿石结构,LZ3C7涂层经1200℃×100 h后保持萤石结构,经1300℃×100 h后形成萤石和烧绿石结构两种相。3种涂层经1300℃×100 h时效后,呈现出不同的微观结构,LZ涂层发生烧结形成微烧结孔,LZ7C3涂层中仍然保持着微裂纹结构,LZ3C7涂层产生大量孔洞。
Three kinds of Ce-modified La2Zr2O7 powders (La2Zr2O7 (LZ), La2 (Zr0.7Ce0.3) 2O7 (LZ7C3) and La2 (Zr0.3Ce0.7) 2O7 (LZ3C7)) were prepared by coprecipitation. The coatings were prepared by plasma spraying. The coatings were aged at 1200 and 1300 ℃ for 100 h. The structure of the powders, the size of the nanocrystals and the lattice constant were observed by scanning electron microscopy, X-ray diffraction and transmission electron microscopy. , As well as the high temperature phase structure evolution and aging behavior of the coating. The results show that LZ and LZ7C3 powders exhibit single pyrochlore structure and LZ3C7 single fluorite structure. With the increase of Ce doping amount, the lattice constant of powder increases. All the three coatings showed the fluorite structure. The LZ and LZ7C3 coatings showed pyrochlore structure after aging at 1200 and 1300 ℃ for 100 h, and the LZ3C7 coating retained the fluorite structure after 1200 ℃ × 100 h , Formed by the 1300 ℃ × 100 h fluorite and pyrochlore two phases. After aging at 1300 ℃ for 100 h, the three coatings showed different microstructures. The LZ coating sintered to form micro-sintered pores. The micro-crack structure was still retained in the LZ7C3 coating, while LZ3C7 coating produced a large number of pores.