热喷涂复合结构MCrAlY/8YSZ热障涂层的抗剥落能力  

Thermally Sprayed Thermal Barrier Coating of MCrAlY/8YSZ with Hybrid Microstructure and Its Spallation Resistance

作　　者：刘福广[1] 陈胜军[2] 潘红根 董鹏 马英民 黄杰 杨二娟[1] 米紫昊[1] 王艳松 雒晓涛[4] LIU Fuguang;CHEN Shengjun;PAN Honggen;DONG Peng;MA Yingmin;HUANG Jie;YANG Erjuan;MI Zihao;WANG Yansong;LUO Xiaotao(Xi'an Thermal Power Research Institute Co.,Ltd.,Xi'an 710054,China;Huaneng International Electricity Co.,Ltd.,Changxin Power Plant,Changxin 313100,China;National Energy Group,Jiaozuo Power Plant Co.,Ltd,Jiaozuo 454100,China;State Key Laboratory for Mechanical Behavior of Materials,School of Materials Science and Engineering,Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]西安热工研究院有限公司,西安710054 [2]华能国际电力股份有限公司长兴电厂,长兴313100 [3]国家能源集团焦作电厂有限公司,焦作454100 [4]西安交通大学金属材料强度国家重点实验室,西安710049

出　　处：《材料研究学报》2021年第4期313-320,共8页Chinese Journal of Materials Research

摘　　要：在陶瓷涂层与金属粘接层之间制备一层NiCoCrAlTaY/YSZ复合过渡层和通过半熔化团聚YSZ粉末制备层状/多孔团状复合结构YSZ隔热层,用SEM表征了涂层的显微组织;依照ASTM C633标准测试了涂层的结合强度;用压痕法测试了陶瓷层的弹性模量和断裂韧性。用激光脉冲法测试了陶瓷层的热导率。用高温水淬快速冷却实验验证涂层的抗剥落性能。结果表明,在不降低涂层隔热效果的前提下复合过渡层和和隔热层显著提高了涂层的抗剥落能力。HVOF制备的NiCoCrAlTaY粘接层组织致密,没有明显的氧化物;APS制备的NiCoCrAlTaY/YSZ复合过渡层内层间的结合良好,组织致密,金属与陶瓷粒子呈现出典型的层状交替分布特征;陶瓷层由典型层状结构内包含约11%未完全熔化团聚粉末形成的弥散分布多孔团状组织构成。复合结构使等离子喷涂TBC的结合强度由25.8 MPa提高到38.6 MPa,陶瓷层的弹性模量和热导率没有明显的变化,但是断裂韧性提高了1倍以上,涂层出现30%剥落的平均水淬周次由19.7次提高到72.1次,表明抗剥落能力显著提高。A thermal barrier coating(TBC)of MCrAlY/8 YSZ with hybrid microstructure was prepared on 15 CrMo stainless steel by means of HVOF spraying technique,namely the coating consists of a hybrid structured YSZ top-coat made of mixture of agglomerated and fused and crushed YSZ powder and a bond coat of NiCoCrAlTaY,while an intermediate layer of NiCoCrAlTaY/YSZ composite was inserted in between the above two coats.The bonding strength and fracture toughness of the YSZ coating can be improved by these two strategies to enhance the spallation resistance of the TBC.Two individual powder feeders were used to feed the NiCoCrAlY and YSZ powder independently into the plasma plume so that the feeding rate and heating experience of both powders can be controlled independently.SEM was used to characterize the coating microstructure.Adhesion of the TBC coating was examined according to ASTM C633 Standard.Elastic modulus,fracture toughness and thermal conductivity of the YSZ layer were measured.Spallation resistance of the coating was assessed by water quenching test from 750°C.The results show that the desired coating microstructure was achieved by HVOF and APS,and all the three layers bond well each other without any interfacial cracks.The adhesion strength of the YSZ coat increases from 25.8 MPa to 38.6 MPa.Evident changes in elastic modulus and thermal conductivity were not detected.A great improvement of 100%in fracture toughness of the YSZ coating was achieved.As a result of all the above measures,the occurrence of 30%area spallation for the top coat could be rose to72.1 cycles during water quenching test,in comparison,only 19.7 for the TBC made of the same material with conventionally desired structure.

关 键 词：材料表面与界面 超超临界锅炉机组 热障涂层 热喷涂 复合结构 抗剥落能力 

分 类 号：TG178[金属学及工艺—金属表面处理]