Effect Of Rare Earth Oxides On Sintering、Structure And Properties Of γ-AlON Ceramic

As a new functional and structural material, γ-AlON transparent ceramic has similar excellent optical and mechanical properties as the sapphire single crystal has, and it is cheaply and easily to be made that can be used in the area of lighting, optical and medical instruments, laser, armor, infrared detection, and many other aspects that becomes the focus in the study of transparent ceramic.This thesis firstly confirmed the single-phase area of the γ-AlON at differernt temperatures with the rapid synthesis process combined with phase analysis,lattice parameter determination that offers the guidance for the choice of proper composition and temperature to synthetize γ-AlON powders. The results show that the lowest synthesis temperature for single phase γ-AlON is1640℃, the single-phase of γ-AlON expands with the rise of temperature.The appropriate powder synthesis temperature is1700℃. The lattice constant of γ-AlON increases linearly with the increase of the contents of the nitrogen.After that we discussed the effect of different sintering temperature、different contents of sintering aids and different composition on sintering,structure and properties of γ-AlON using the powders that synthetized at1700℃as raw materials. The results show that the suitable sintering temperature for the sintering of y-AlON is1925℃.The appropriate amounts of Y2O3/La2O3in the y-AlON are0.1wt%and0.045wt%,respectively.the optimum composition is27mol%AlN.Under the optimum conditions, Y2O3/La2O3as the additves,The micro structure of y-AlON is uniform and with few of pores,the relative density is99.84%and99.82%,the inline transmittance is67%and68%in the visiable light area (the thickness is2mm),the hardness is14.34±0.21and15±0.11GPa, the Young’s modulus is328and324GPa,respectively.