Effects Of Sintering Aids On The Physicochemical Properties Of YTaO₄ Ceramics

YTaO₄ ceramic series material is one of the most potential thermal barrier coating materials,its high melting point,low thermal conductivity and its special iron-elastic phase transition structure,which endows it with special potential value.The research on thermal barrier coating of YTaO₄ ceramics has been mature,and its excellent properties in other aspects need to be further developed and studied.According to previous scholars study of YTaO₄ceramic material,mixed with different kinds of content in the ceramic sintering additives,to optimize the sintering system,using isostatic pressing method test,high temperature pressureless sintering,get the sample in the way of using vacuum annealing,mainly study the influence on ceramic in the chemical and physical properties and so on.When different kinds and contents of sintering additives are added into YTaO₄ ceramics,the second phase structure is generated in the ceramics under high temperature state,so that point defects are formed in the ceramics,making the ceramics form liquid phase at low temperature,reducing the sintering temperature of ceramics.When 6%alkali metal sintering assistant Li₂O₃ is added into the ceramics,the light transmittance of YTaO₄ ceramics can be stable above 80%,which indicates that YTaO₄ ceramics has superior optical properties and has the potential to be developed into optical ceramics.The alkaline earth metal sintering assistant MgO is mixed into YTaO₄ ceramics,and part of Mg²⁺ions enter the interior of the stable crystal lattice to replace the Y³⁺ions in the original matrix material,resulting in lattice distortion and reaction to generate the second phase.Under the sintering system of 1600℃,the gap between ceramic particles is fully filled through flow mass transfer.The abnormal growth of grains was inhibited,which blurred the grain boundary between the ceramics.When the addition amount was 2%,the Young’s modulus and hardness of the ceramics were the minimum,and the hardness value was only 3.05 GPa and the Young’s modulus was 53.31 GPa.With the increase of the addition amount,the higher the density of the ceramics,the Young’s modulus and hardness gradually increased.The Young’s modulus is170.95 GPa and hardness is 9.68 GPa.The sintering additives of ceramic sintering is not mixed or which is mixed,vacuum annealing in the same situation,appropriate to the amount of research has shown that incorporation of sintering additives Al₂O₃,its influence of the sintering densification degree,not to the expected requirements,within the scope of the room temperature to 1200℃,thermal expansion coefficient of the material does not vary with temperature changing,young’s modulus and hardness of the material changes,When the sintering additive is 8%,the hardness and Young’s modulus reach the maximum,the maximum hardness is 15.09 GPa,an increase of82.9%,and the maximum Young’s modulus is 219.15 GPa,an increase of 22.75%.The Young’s modulus and hardness of YTaO₄ceramics can be effectively improved by adding alumina powders with different contents as sintering additives.In the high temperature state,the expansion properties of the ceramics doped with sintering additives are basically unchanged under the influence of temperature change,and in the wavelength range of 200-800cm^-1,the light transmission efficiency of the ceramics is obviously better than that of the ceramics without sintering additives,which fully demonstrates that YTaO₄ ceramics has a high potential in the field of high temperature resistant laser ceramics.