Ni基定向凝固高温合金表面CoCrAlY黏结层在1050℃长期热暴露条件下的组织演变

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• 英文论文题名：Microstructure Evolution of CoCrA1Y Bond Coating Deposited on the Ni Directionally Solidified Superalloys during Long-term Exposure at 1050℃
• 论文作者：任维鹏 ; 李青 ; 宋尽霞 ; 肖程波 ; 何利民
• 英文论文作者：Ren Weipeng ; Li qing ; Song Jinxia ; Xiao Chengbo ; He Limin ; Science and Technology on Advanced High Temperature Structural Materials Laboratory ; Beijing Institute of Aeronautical Materials ; Metal Corrosion and Surface Protection Laboratory ; Beijing Institute of Aeronautical Materials
• 年：2015
• 作者机构：北京航空材料研究院先进高温结构材料重点实验室;北京航空材料研究院金属腐蚀与防护实验室;
• 论文关键词：定向凝固 ; 高温合金 ; 黏结层 ; 组织演变
• 英文论文关键词：directionally solidified ; superalloys ; bond coating ; microstructure evolution
• 会议召开时间：2015-05-20
• 会议录名称：第十三届中国高温合金年会论文集
• 英文会议录名称：Proceedings of the 13th China Superalloys Conference
• 语种：中文
• 分类号：TG174.4
• 学会代码：ZGJS
• 会议名称：第十三届中国高温合金年会
• 会议地点：中国北京
• 主办单位：中国金属学会高温材料分会
• 学会名称：中国金属学会
• 页数：4
• 文件大小：1452k
• 原文格式：O
• 会议级别：全国

摘要

CoCrAlY涂层常被用作热障涂层的黏结层,其在高温条件下的组织稳定性是影响其使用寿命的关键因素。本实验采用电子束物理气相沉积EBPVD法,在Ni基定向柱晶高温合金DZ466和DS GTD111表面沉积热障涂层(分别表示为DZ466-TBC和DS GTD111-TBC)。研究1050℃长期热暴露条件下CoCrAlY黏结层与基体合金的交互作用及组织演变规律。实验结果表明,沉积态CoCrAlY黏结层主要由γ-Co固溶体和β-CoAl相组成。1050℃条件下热暴露后,两种基体合金表面CoCrAlY黏结层内β-CoAl相不断向γ相转变,即出现贫铝退化现象。两种基体合金表面CoCrAlY黏结层出现不同的退化模式,DZ466-TBC黏结层仅在靠近陶瓷层侧出现贫铝区,而DS GTD111-TBC黏结层在陶瓷层与基体合金侧都出现贫铝区,这主要是由两种基体合金中不同的Al元素含量及其所导致的元素扩散速率的不同所造成的。随着热暴露过程的进行,DZ466-TBC和DS GTD111-TBC的扩散层附近基体合金内都形成γ′粗化区并出现γ/γ′组织筏排化现象,扩散层界面前沿相转变反应以及Ni、Al等元素互扩散行为的差异导致γ′粗化区内γ′体积分数以及γ/γ′组织筏排化程度的不同,并且以DZ466-TBC中的程度较大。
CoCrAlY coating was widely used as the bond coating of the thermal barrier coatings(TBCs),and the lifetime always depend its microstructure stability at high temperature.Here,the TBCs were deposited on directionally solidified superalloys namely the DZ466 and DS GTD111 by electron beam physical vapor deposition,for short named DZ466-TBC and DS GTD111-TBC,then the microstructure evolution of the CoCrAlY bond coating and the interaction between the bond coating and the substrate superalloys were examined.Results suggest that the as deposited CoCrAlY bond coating is made up ofγ-Co and β-CoAl,β-CoAl phase gradually transforms to be γ-Co phase in the two TBCs systems,i.e.the degradation by consuming Aluminum.Different degradation modes present at the two TBCs systems.Al depletion zone grows near the top coating in DZ466-TBC,while it developing from the side both of the top coating and the interdiffusion zone(IDZ),which is ascribed to the different Al composition and the corresponding diffusion rate.Coarse γ' and γ/γ' rafting structure are found in both of the DZ466-TBC and DS GTD111-TBC During the exposure.Reaction of the phase transformation near the interface of the IDZ/substrate,as well as the diffusion behavior of Ni or Al make higher volume fraction of γ' in coarse γ' zone and severe γ/γ' rafting structure.

引文

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