【摘要】 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。更多还原

【Abstract】 Three different Ce modified La₂Zr₂O₇ powders（La₂Zr₂O₇（LZ）, La₂（Zr0.7Ce0.3）₂O₇（LZ₇C₃）, La₂（Zr0.3Ce0.7）₂O₇（LZ₃C₇）） were prepared by a co-precipitation method. The three coatings were prepared by a plasma spraying method. The coatings were aging treated at 1200 and 1300 °C for 100 h. The scanning electron microscopy, X-ray diffraction, transmission electron microscopy and other methods were used to compare the crystal structures of the powders, nano grain size, lattice constants, the high-temperature phase structure evolution and aging behavior of the coatings. The results show that LZ and LZ7C3 powders present a single pyrochlore structure, while LZ₃C₇ powder presents a single fluorite structure. As the Ce content increases, the powder lattice constant increases. All three as-prepared coatings show fluorite structures. LZ and LZ7C3 coatings transform into pyrochlore structure after aging at 1200 and 1300 °C for 100 h. LZ₃C₇ coating maintains fluorite structure after aging at 1200 °C for 100 h, while it transforms into two phases（fluorite and pyrochlore structure） after aging at 1300 °C for 100 h. After aging at 1300°C for 100 h, the three coatings exhibit different coating microstructures. After LZ coatings are sintered, micro holes are formed, LZ₇C₃ coatings remain microcracks structure, and many holes are formed in LZ3C7 coatings.更多还原