【摘要】 在Ni基单晶高温合金基体上 ,采用磁控溅射沉积Ni30Cr12Al0 .3Y粘结层 ,电子束物理气相沉积 (EB -PVD)氧化锆陶瓷面层 ,制备了热障涂层 .粘结层的晶粒尺寸小于 10 0nm ,为纳米结构 ,具有优异的抗氧化性能 ;陶瓷面层为柱状结构 ,有较好的应变允许度 .XRD分析表明 ,沉积态的陶瓷层存在大量的非平衡正方相 (t′) ,还有少量的立方相 (c)和单斜相 (m) ,t′相在冷却时不会转变为m ,对陶瓷的高温稳定性有重要的作用 .在 10 5 0℃下 ,对单晶合金基体和热障涂层进行了循环氧化实验 .结果表明 ,单晶合金经过几次循环后氧化膜发生剥落 ,10 0次循环氧化后 ,表面氧化物主要由NiO和少量的Al2 O3 以及由于Kirkendell效应造成的孔洞组成 ;而热障涂层经过 10 0次循环后 ,表面没有剥落 ,但有微裂纹出现 ,粘结层与陶瓷层之间的热氧化产物 (TGO)为Al2 O3 .30 0次循环氧化后 ,TGO与粘结层之间有裂纹产生 .更多还原

【Abstract】 The thermal barrier coatings (TBC),which Ni30Cr12Al0.3Y bond coating was deposited by magnetron sputtering and ZrO 2 ceramic top coating was deposited by electron beam-physical vapor deposition (EB-PVD),was produced on Ni-base superalloy.The bond coatings,which the mean grain size was less than 100 nm,were nanostructured coatings,and had good oxidation-resistance.The ceramic topcoats,which were columnar structure,permitted larger strain in the coatings.The as-deposited ceramic coatings consisted of large quantity nonequilibrium tetragonal (t′),a small amount cubic (c) and monoclinic (m) phases.The t′ phases,which had important role to the stabilization of zirconia at high temperature,can not directly transform into m phase during cooling.During cyclic oxidation at 1050℃,the scale of the cast alloy had spalled after two cycles.After 100 cycles,the surface scale of single-crystal superalloy was mainly composed of NiO?Cr 2O 3,a little Al 2O 3 and pores by the Kirkendall effect.However,the ceramic coatings,which had microcrack,have not spalled and the thermally grown oxide (TGO) was Al 2O 3.There were some microcrack between TGO and bond coating after 300 cycles.更多还原