| Thermal barrier coatings is one of the key technologies of advanced gas turbines.With the increase of the hot gas temperature, the current material Zr O2 partically stabilized with Y2O3(YSZ), for the thermal barrier coatings(TBCs) will no longer be able to meet the more exacting requirements due to the poor long-term phase stability and strong sintering tendency.Urgently, development efforts have to focused on selecting novel TBCs ceramics material.In this paper,the powder Ba(Mg1/3Ta2/3)O3 is compounded by the way of Solid-phase synthesis method with the raw materials powder of Ba CO3, Mg O, Ta2O5,then determin the calcined parameters by the phase analysis of the product. Futhermore, prepare the spherical agglomerated powder by the means of milling broken and spray drying.Powder which according with the plasma spray requirments is prepared by the means of sintering at high temperature.The sintering parameters were determined by the phase analysis and particle size analysis.Additonal,the Ba(Mg1/3Ta2/3)O3 and Ba(Mg1/3Ta2/3)O3/YSZ thermal barrier coatings were prepared by atmosphere plasma spraying method, then evaluated the properties of coatings,including bonding strength, porosity, thermal shock resistance and anti ablation property.The results show that it is possible to aynthesize Ba(Mg1/3Ta2/3)O3 of perovskite structure by calcining at 1400℃ for 2 hours;After sintering at 1500℃, the ceramics poeders, with the flow velocity about 47.13s/50 g and the bulk density about 1.81g/cm3 were suitable for atmosphere plasma spaying. Ba(Mg1/3Ta2/3)O3 and Ba(Mg1/3Ta2/3)O3/YSZ coatings were prepared by the appropriate parameters(Primary gas Ar 90 scfh, Secondary gas H2 2scfh, Carrier gas Ar 8scfh,Current 900 A,Powder feed rate 3rpm,Distance 75mm) of atmosphere plasma spary process.The bonding strength of the Ba(Mg1/3Ta2/3)O3 coating is 25.7MPa and the porosity of the coating is 4.42%.The cycles of thermal shock of the coating is 9 times.The coating failure mode was the production of the Ba5Ta4015. The coating had no spalling failure after 1650℃ thermal ablation 18 minutes.The bonding strength of the Ba(Mg1/3Ta2/3)O3/YSZ coating is 30.4MPa. The coating had no spalling failure after 1650℃ thermal ablation 20 minutes. |
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