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采用磁控溅射在大气等离子喷涂的ZrO_2-7%Y_2O_3(7YSZ)热障涂层表面制备一层厚度约15μm铝膜,对镀有铝膜的热障涂层样品在700、900℃分别保温1h和5h进行真空热处理。采用场发射扫描电子显微镜对经真空热处理前后镀铝热障涂层的微观结构进行表征。采用X射线衍射和透射电子显微镜对经真空热处理前后镀铝热障涂层的物相变化进行分析。对等离子喷涂的7YSZ原始热障涂层和镀铝真空热处理后的热障涂层进行室温粒子冲刷性能对比。结果表明:镀铝热障涂层经真空热处理后在涂层表面出现疏松表层和致密底层,其成分主要为α-Al_2O_3,其中致密底层来源于Al膜与ZrO_2的高温原位反应且该层有较高的显微硬度。此外,冲刷实验后发现镀铝真空热处理后热障涂层的冲刷性能比无镀铝热障涂层有较大的提高。
A 15μm-thick aluminum film was prepared on the surface of the ZrO_2-7% Y_2O_3 (7YSZ) thermal barrier coating by atmospheric plasma spraying by magnetron sputtering. The thermal barrier coating samples coated with aluminum film were respectively insulated at 700 and 900 ℃ 1h and 5h vacuum heat treatment. The microstructure of the aluminized thermal barrier coatings before and after vacuum heat treatment was characterized by field emission scanning electron microscopy. The phase changes of aluminized thermal barrier coatings before and after vacuum heat treatment were analyzed by X-ray diffraction and transmission electron microscopy. The plasma spraying 7YSZ original thermal barrier coating and aluminum vacuum heat treatment after the thermal barrier coating at room temperature particle erosion performance comparison. The results show that the aluminized thermal barrier coating has a loose surface layer and a dense underlayer on the surface of the coating after vacuum heat treatment, and its composition is mainly α-Al_2O_3. The dense underlayer comes from the in-situ reaction of Al film and ZrO_2 at high temperature. Higher microhardness. In addition, after the scouring experiment, it was found that the erosion performance of the thermal barrier coating after vacuum heat treatment of aluminum plating is greatly improved than the non-aluminized thermal barrier coating.