采用Pt、Dy改性粘结层的铈酸镧/氧化锆双陶瓷层抗氧化行为研究

Oxidation Resistance Behavior of La_2Ce_2O_7/YSZ Double Ceramic Layer with Pt/Dy Doped Bond Coat

目的研究Pt、Dy改性粘结层的铈酸镧/氧化锆双陶瓷层的抗氧化行为。方法采用电镀+EB-PVD的方式在高温合金表面制备带有Pt、Dy掺杂NiAl粘结层的热障涂层(Thermal Barrier Coatings TBCs)。采用双陶瓷层结构设计,顶层为铈酸镧(La_2Ce_2O_7),底层为氧化锆(YSZ)。对涂层在1200℃条件下的热循环行为、微观组织以及失效机制进行了研究。结果经过500次循环后,不掺杂涂层YSZ层与热生长氧化物(TGO)处出现了大量裂纹,Pt/Dy共掺杂的涂层经过1000次循环后界面处结合良好,仅仅是在La_2Ce_2O_7陶瓷顶层中出现了少量的微裂纹。结论在粘结层中加入Pt元素,能有效抑制互扩散区难溶相的析出,延缓涂层的蜕化。

Objective To study oxidation resistance behaviors of La2Ce2O7/YSZ double ceramic layer with Pt/Dy doped bond coat.Methods The method of plating + EB - PVD was used to prepare Thermal Barrier Coatings (TBCs) with Pt/Dy doped bond coat on high temperature alloy surface.The double-ceramic layer structure was designed with lanthanum cerium acid as top (La2Ce2O7),zirconia (YSZ) as bottom.Heat cycle behavior,microstructure and failure mechanism of coating at 1200 ℃ were studied.Results After 500 cycles,a large number of cracks appeared on undoped YSZ coating layer and thermally grown oxide (TGO).The interface of Pt/Dy doped coating was combined properly after 1000 cycles.Only a small amount of micro cracks appeared at La2Ce2O7 ceramic top.Conclusion Pt elements in the adhesive layer can effectively inhibit refractory phase precipitation of mutual diffusion area of and delay degenerateion ofthe coating.