LZO对热障涂层中粘结层氧化的抑制行为研究

Inhibition Behavior of LZO on the Oxidation of Bond-coat in Thermal Barrier Coatings

为了阐明La2Zr2O7(LZO)对热障涂层(TBCs)中粘结层氧化的抑制作用,利用爆炸喷涂(D-gun)在310S基体上制备NiCoCrAlY粘结层,大气等离子(APS)制备单陶瓷8YSZ涂层和双陶瓷LZO/8YSZ涂层。采用SEM、EDS和XRD表征了不同结构TBCs喷涂态及高温氧化后的微观组织和相结构。结果表明:1100℃下等温氧化(100 h)后双陶瓷LZO/8YSZ与单陶瓷8YSZ热障涂层相对氧化增重分别为2.82和3.13 mg/cm^2,热生长氧化物(TGO)生长速率常数Kp分别为5.79×10^-2和6.26×10^-2μm2/h,厚度分布范围分别为3.75~5.25μm和5~5.5μm。相比单陶瓷TBCs,LZO/8YSZ双陶瓷TBCs中粘结层表现出氧化增重少、TGO生长速率低、粘结层中β相转变慢等明显特征。

In order to clarify the inhibitory effect of LZO(La2Zr2O7)on the oxidation of bond-coat in thermal barrier coatings(TBCs),NiCoCrAlY bond-coat was deposited on 310S substrate by detonation gun spraying,and single ceramic 8YSZ coating and LZO/8YSZ double ceramic coating were deposited by air plasma spraying.The microstructure and phase structure of TBCs before and after high temperature oxidation were analyzed by SEM,EDS and XRD.The results show that the relative oxidation mass gain of the double ceramic LZO/8YSZ and the single ceramic 8YSZ structure are 2.82 and 3.13 mg/cm2,respectively.Their TGO(thermally grown oxide)growth rate constant Kp is 5.79×10^-2 and 6.26×10^-2μm2/h,respectively.And the corresponding thickness distribution range is 3.75~5.25μm and 5~5.5μm,respectively after isothermal oxidation(100 h)at 1100°C.Compared with the single ceramic 8YSZ TBCs,TGO exhibits obvious characteristics which are less oxidation mass gain,lower growth rate,and slowerβphase transition in bond-coat of the LZO/8YSZ double ceramic TBCs.