稀土改性NiCoCrAlY层对YSZ和LZ/YSZ热障涂层高温性能的影响

Effect of Rare Earth Modified NiCoCrAlY Coating on the Properties of YSZ and LZ/YSZ TBC by High Temperature Oxidation Test

以纳米结构的La_2O_3、ZrO_2、8YSZ粉体为原材料,利用纳米调控技术制备可用于等离子喷涂的粉体材料;利用等离子喷涂技术在304不锈钢基体上分别喷涂含未改性粘结打底层和改性粘结打底层的YSZ和LZ/YSZ两种结构的热障涂层。研究了热障涂层的结合强度和抗氧化行为,并分析稀土改性的粘结打底层对其组织结构的影响。根据涂层氧化不同时间后涂层的截面形貌图及能谱图分析其氧化后的组织结构,进而研究稀土改性粘结打底层对热生长氧化物(TGO)层的影响。结果表明:含改性粘结打底层的双陶瓷型热障涂层La_2Zr_2O_7+8YSZ+mNiCoCrAlY在800℃和900℃下均具有最低的氧化速率,氧化增重速率常数分别为0.04372mg^2·cm^(-4)·h^(-1)和0.12406mg^2·cm^(-4)·h^(-1),比含未改性粘结打底层的La_2Zr_2O_7+8YSZ+NiCoCrAlY涂层分别降低45%和36%,说明改性粘结打底层提高了热障涂层的抗氧化性能。

Nanostructure La2O3, ZrO2 and 8YSZ powders have been used as raw material, nanostructured 8YSZ and La2Zr2O7 feedstock has been prepared by Nano-particle granulation technique. The nanostructured 8YSZ coating, double ceramic layer LZ/8YSZ TBC has been prepared onto the 304-stainless steel substrate with the two kinds of NiCoCrAlY as bond-coat. Study the bonding strength and oxidation resistance of the rare earth modi？ed adhesive layer in the thermal barrier coating. The feedstock, microstructure and phase compositions were studied by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. After high temperature oxidation, according to the sectional morphology and EDS of the thermal coating, analysis the organization and structure of thermal coating, and then study the impact of rare earth modi？ed adhesive layer on the TGO layer. The results show that the double ceramic thermal barrier coating La2Zr2O7＋8YSZ＋m-NiCoCrAlY under 800℃ and 900℃ have the lowest rate of oxidation, the oxidation rate of weight gain are 0.04372mg2·cm^-4·h^-1 and 0.12406mg2·cm^-4·h^-1, than the unmodified La2Zr2O7＋8YSZ＋NiCoCrAlY coating decreased by 45% and 36%, indicating that its antioxidant properties can be improved by rare earth modi？ed NiCoCrAlY adhesive layer.