The Effect Of Doping On The Infrared Radiation Suppression Performance Of Ceramic Materials Used In ZrO₂-based Thermal Barrier Coatings

With the development of aerospace technology,it is important to increase the thrust of the engine.Aeroengine turbine blades work long hours at high temperatures,and the thrust-to-weight ratio is increased,which is followed by an increase in the inlet temperature before the engine turbine.The proportion of thermal radiation is getting heavier and heavier.It is an urgent problem to shield high-temperature radiation.For new aero-engine thermal barrier coatings,it is very meaningful to study the inhibition of heat radiation.In this paper,the rare earth doped zirconia was used to improve the emissivity of the coating material.The purpose of suppressing infrared radiation is achieved under the premise of satisfying basic properties such as good high temperature phase stability and low thermal conductivity.Nickel oxide,cerium oxide,cerium oxide,cerium oxide and zirconia powder were used as raw materials.Composite ceramic materials prepared by high temperature solid phase synthesis.X-ray diffractometry and scanning electron were used to investigate high temperature phase stability.Thermophysical properties such as specific heat,thermal diffusivity and thermal conductivity of the composite ceramics were investigated by means of laser thermal conductivity test.The emissivity of ceramic samples were tested by using Fourier spectrometer.The phase structure study shows that the NiO,Er₂O₃,Yb₂O₃ ternary co-doping system has good high temperature phase stability at 300?for 1500?,respecially when the doping amounts of Er₂O₃ and Yb₂O₃ are 2%and 4%,respectively.The results of thermophysical properties shows that:the ternary co-doping of NiO,Er₂O₃ and Yb₂O₃ can effectively reduce the thermal conductivity of ceramic materials effectively.2EYNYSZ?1.45¹.55 W/?m·K??ceramic thermal conductivity of the sample from room temperature to 1500?temperature of each corresponding to the thermal conductivity of the same are lower than the thermal conductivity of YSZ?1.68².08 W/?m·K??.Compared with YSZ,it is reduced by about 18%,indicating that with the doping amount increasing,the thermal conductivity gets lower and lower,and it has better insulation effect than YSZ under the same conditions.The results of emissivity shows that:The emissivity of ceramic materials after heat treatment at 1500°C for 5h at different temperatures was tested.The higher the temperature,the higher the emissivity.Doping NiO alone can effectively improve the emissivity.Erbium and ytterbium co-doped patterns have high emissivity in the 0.98?m and 1.55?m bands.Nickel,erbium and ytterbium co-doped not only havs a high emissivity as a whole,but it can produce a high emissivity in a specific band.Among the five ceramic systems,2EYNYSZ ceramic materials exhibit excellent infrared radiation resistance.And it has low thermal conductivity,good high temperature phase stability.The research results can provide direction for the design and process improvement of thermal barrier coating components.