| 引用本文: | 董会， 杨冠军， 雒晓涛， 李长久.混合氧化物对等离子喷涂热障涂层热循环寿命的影响[J].中国表面工程,2015,28(1):21~28 |
| DONG Hui, YANG Guanjun, LUO Xiaotao, LI Changjiu.Effects of Mixed Oxides on Thermal Cyclic Lifetime of Plasma-sprayed Thermal Barrier Coatings[J].China Surface Engineering,2015,28(1):21~28 |
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| 摘要: |
| 采用梯度热循环试验与理论模型相结合的方式研究了混合氧化物对热障涂层寿命的影响。喷涂态热障涂层系统由Inconel 738 基体、冷喷涂沉积的NiCoCrAlTaY粘结层(BC)及大气等离子喷涂制备的ZrO2+ Y2O3(8%) 陶瓷层组成。在1 150 ℃空气气氛条件下，经过保温20 h制备了含有混合氧化物的涂层。每个热循环包括70 s的加热，50 s的保温及120 s的压缩空气冷却。陶瓷层表面最高温度为1 150 ℃，此时250 μm厚的陶瓷层隔热150 ℃。结果表明： 涂层中存在混合氧化物时，其寿命显著降低，且涂层寿命降低程度与混合氧化物和αAl2O3生长诱发的YSZ应变量，以及混合氧化物的覆盖率有关。与αAl2O3相比，较高生长速率的混合氧化物易诱发YSZ产生较高的应变，过早地诱发涂层未结合界面扩展、合并，进而导致涂层快速失效。 |
| 关键词: 热障涂层（TBC） 混合氧化物 热生长氧化物（TGO） 梯度热震 |
| DOI：10.11933/j.issn.1007-9289.2015.01.004 |
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| Effects of Mixed Oxides on Thermal Cyclic Lifetime of Plasma-sprayed Thermal Barrier Coatings |
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DONG Hui, YANG Guanjun, LUO Xiaotao, LI Changjiu
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State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049
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| Abstract: |
| The influence of mixed oxides on durability of atmospheric plasmasprayed (APS) thermal barrier coatings (TBCs) in gradient thermal cycling test was quantitatively examined through equivalent thermally grown oxide(TGO) thickness. The TBC system consisted of Inconel 738 substrate, coldsprayed NiCoCrAlTaY bond coat (BC) and APS 8% yttriastabilized zirconia (YSZ) ceramic topcoat. Mixed oxides were fabricated by high temperature oxidation of TBC samples at 1 150 ℃ for 20 h in air atmosphere. Each thermal cycle consisted of a 70 s heating, a hold of 50 s followed by 120 s cooling by compressed air. The peak temperature of YSZ surface was 1 150 ℃ with 150 ℃ temperature gradient across 250 μm thick YSZ during the gradient thermal cycling test. The results show that the thermal cyclic lifetime of TBCs significantly reduces when mixed oxides form in TBCs, and the reduced trend of lifetime is related to YSZ strain caused by mixed oxides and αAl2O3 and coverage of mixed oxides. Compared with αAl2O3, mixed oxides prematurely induce propagation and coalescence of the nonbonded interfaces between YSZ lamella because of the higher strain in YSZ caused by higher growth rate, which induce the premature failure of TBCs. |
| Key words: thermal barrier coating (TBC) mixed oxides thermally grown oxide (TGO) gradient thermal shock |
