【作者】 李勇； 张强； 李长久； 杨冠军； 李成新；

【Author】 Yong Li Qiang Zhang Guan-Jun Yang Cheng-Xin Li Chang-Jiu Li State Key Laboratory for Mechanical Behavior of Materials,School of Materials Science and Engineering.Xi’an Jiaotong University,Xi’an,Shaanxi,710049,P.R.China

【机构】 西安交通大学材料金属材料强度国家重点实验室；

【摘要】 冷喷涂可以制备几乎无氧化的合金涂层,可以用于制备高温热障涂层的高温合金结合层而替代成本较高的真空等离子喷涂。本研究利用冷喷涂制备NiCoCrAlY粘接层,采用等离子喷涂制备YSZ陶瓷涂层,利用热循环考察了热处理后的热障涂层的失效特征。考察了结合层表面TGO的生长特征与冷喷涂涂层表面形态的关系,及其对热障涂层失效的影响。结果表明冷喷涂粘接层表面沉积的合金颗粒因变形有限,呈现半球状形态。TGO的主要成分为α-Al₂O₃,其形态与结合层表面半球状形貌有关,在低谷处呈现均匀分布,而在半球状凸起部位呈层状结构。导致热障涂层失效的主要裂纹位于距YSZ/TGO界面约30—50微米的YSZ中.部分裂纹位于TGO中以及TGO/YSZ界面.其失效主要由界面层状TGO的快速间歇式生长引起。更多还原

【Abstract】 Cold spray is a promising technique by which the coating can be of high purity from oxidation.NiCoCrAlY alloy powder was deposited on Mar-M247 substrates by cold spray as bond coat on which YSZ coating was deposited by plasma spraying.All TBCs were pre-treated and thermal cycled.The surface morphology of cold sprayed bond coat,the failure models of TBCs and the characterization of TGO were examined.Both the relationship between growth of TGO and the surface morphology and the effects of growth of TGO on the failure of TBCs were investigated.It is found that alloy par- ticles deform partially after impact on the substrate and almost keep semispherical.TGO is mainly composed ofα-Al₂O₃, morphology of which is related to the surface morphology of bond coat.Multilayered TGO dominantly forms at the tops of protrusions on the bond coat and basically keeps uniform at trough in thickness.Failure of TBCs is related to the rapid and intermittent growth of layered TGO.Cracks inducing the failure of TBCs mainly locate within YSZ coat about 30-50μm from the interface and partially at the interface of YSZ/TGO.更多还原