氧化铝半透明陶瓷制备及性能研究

Preparation and Properties of Translucent Alumina Ceramics

通过球磨工艺对商业化氧化铝粉体进行改性,改性后粉体经干燥、成型和烧结获得了氧化铝半透明陶瓷.相比空气气氛,还原氢气气氛烧结有助于氧化铝坯体中氧空位的生成,从而提供传质扩散通道,获得致密化陶瓷.随着氧化铝烧结温度的升高,陶瓷透过率进一步提升,但烧结温度继续升高会引发二次晶粒长大,形成更大的晶界气孔,严重影响透过率.优化的烧结工艺为还原氢气气氛下1820℃烧结.经双面抛光后,1 mm厚样品的最大直线透过率达到51%.

The commercial alumina powder is modified by ball-milling process, and the modified powder is dried,shaped and sintered to obtain translucent alumina ceramics. Compared with air atmosphere, sintering in reduced hydrogen atmosphere contributes to the formation of oxygen vacancies in alumina green bodies, thus providing mass transfer and diffusion channels and obtaining dense ceramics. With the increase of sintering temperature, the transmittance of ceramics increases further, but the further increase of sintering temperature will result to the growth of secondary grains growth and the formation of larger grain boundary pores, which seriously affects the transmittance. The optimum sintering process is sintered at 1 820 ℃ in a reducing hydrogen atmosphere. After double-sided polishing, the maximum linear transmittance of the sample with a thickness of 1 mm is 51%.