Mechanism of high temperature oxidation resistance improvement of double-layer thermal barrier coatings (TBCs) by La
Mechanism of high temperature oxidation resistance improvement of double-layer thermal barrier coatings (TBCs) by La
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La提高双层热障涂层（TBC）高温抗氧化性能的机理
DOI：
10.1016/j.ceramint.2019.01.251
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发表时间：
2019
影响因子：
5.2
通讯作者：
Fu Bin-Guo
中科院分区：
文献类型：
--
作者：
Dong Tian-Shun;Wang Ran;Di Yue-Lan;Wang Hai-Dou;Li Guo-Lu;Fu Bin-Guo
为了揭示La提高双层热障涂层（tbc）高温抗氧化性的机理，采用大气等离子喷涂法制备了两种tbc，其陶瓷涂层分别为单层zro2单键2o3 （YSZ）和双层La2Zr2O7(LZ)/YSZ。随后，两种tbc在1100 ℃氧化。实验结果表明，LZ的存在阻止了键合涂层的快速氧化和热生长氧化物（TGO）的快速生长，导致TGO膨胀的频率和TGO中尖晶石氧化物的数量减少。La3+可以控制TGO的相变，即降低从亚稳相θ- al2o3到稳定相α-Al2O3的转变速率，从而降低残余应力。La3+阻碍了键合涂层中阳离子的扩散，从而进一步抑制了尖晶石相的形成，有利于TGO与涂层的粘附。因此，由于LZ陶瓷涂层的存在，双层LZ/YSZ tbc具有优于单层YSZ的高温抗氧化性。
In order to reveal the mechanism of high temperature oxidation resistance improvement of double-layer thermal barrier coatings (TBCs) by La, two kinds of TBCs were prepared by atmospheric plasma spraying, whose ceramic coating were single-layer ZrO2single bondY2O3(YSZ) and double-layer La2Zr2O7(LZ)/YSZ, respectively. Subsequently, the two TBCs were oxidized at 1100 °C. The experimental results show that the presence of LZ prevented the rapid oxidation of bonding coating and the rapid growth of thermal growth oxide (TGO), which led to the decrease in frequency of TGO bulges and the number of spinel oxides in TGO. La3+can control the phase transformation of TGO, i.e. reduce the transition rate from metastable phase θ-Al2O3to stable phase α-Al2O3, thereby reduce the residual stress. La3+made the diffusion of cations in bonding coating to be obstructed, thus the formation of spinel phase was inhibited further, which was beneficial to the adhesion between TGO and coating. Therefore, double-layer LZ/YSZ TBCs exhibited superior high temperature oxidation resistance to single-layer YSZ due to the presence of LZ ceramic coating.