厚质梯度NiCoCrAlY/YSZ热障涂层的制备及结合性能  

Bonding Property of High-thickness Gradient NiCoCrAlYAfSZ Thermal Barrier Coatings

作　　者：种南京 柳琪 李天庆 王玉[1] 白宇[1] CHONG Nanjing;LIU Qi;LI Tianqing;WANG Yu;BAI Yu(State Key Laboratory for Mechanical Behavior of Materials,Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]金属材料强度国家重点实验室,西安交通大学材料学院,陕西西安710049

出　　处：《铸造技术》2021年第7期555-559,564,共6页Foundry Technology

基　　金：国家自然科学基金青年基金(52005388);国家重点研发计划(2018YFB2004002);中国博士后基金(2019M653598);陕西省自然科学基础研究计划(2019TD-020及2019JQ-586)

摘　　要：热障涂层的隔热性通常随着涂层厚度的增加而提高。然而,厚度的增加会导致其内部较低的界面结合,这严重制约了热障涂层的可靠性及使用寿命。采用一种新型高效的超音速等离子同步双送粉方法,在基体上沉积了一系列毫米级厚度NiCoCrAlY/YSZ梯度热障涂层。通过拉伸法测试了涂层的结合强度,探讨涂层厚度及微观结构对结合强度的影响。同时采用有限元模拟方法,验证了热障涂层内部残余应力与结合强度间的关系。结果表明,随着涂层厚度从1000μm增加到2500μm时,涂层的结合强度由44.5 MPa逐渐降低到29.4 MPa,结合强度的降低归因于涂层沉积过程中残余应力的累积,由于其不同的累积位置,导致断裂部位由粘接层逐渐向梯度过渡区转移,最后在陶瓷层内部发生断裂。The thermal insulation property of thermal barrier coatings(TBCs)can be significantly improved with increasing the coating thickness.However,the increase in thickness leads to a lower interfacial bond inside,which severely restricts the reliability and service life of TBCs.A series of NiCoCrAlYA'SZ gradient thermal barrier coatings with millimeter thickness were deposited on the substrate by a novel and efficient supersonic plasma synchronous dual powder feeding method.The bond strength of the coating was tested by tensile method,and the influence of coating thickness and microstructure on the bond strength was discussed.At the same time,the finite element simulation method was used to verily the relationship between the internal residual stress and the bonding strength of TBCs.The results show that when the thickness of the coating increases from 1000μm to 2500μm the bonding strength of the coating gradually decreases from 44.5 MPa to 29.4 MPa.The decrease of the bonding strength is due to the accumulation of residual stress in the deposition process of the coating.The fracture site is gradually transferred from the adhesive layer to the gradient transition zone due to the different accumulation positions of the residual stress.Finally,fracture occurs inside the ceramic layer.

关 键 词：厚质梯度涂层 同步送粉 等离子喷涂 结合强度 有限元模拟 

分 类 号：TG174.4[金属学及工艺—金属表面处理]