AlON透明陶瓷的制备与性能

PREPARATION AND PROPERTIES OF AlON TRANSPARENT CERAMICS

以碳热还原法制得的氮氧化铝(aluminum oxynitride,Al23O18N5,AlON)粉体为原料,Y2O3为烧结助剂,采用热压烧结法在1850～1950℃和15～25MPa下制备了AlON透明陶瓷。通过X射线衍射、扫描电子显微镜和红外光谱仪分析了AlON陶瓷样品的相组成、显微形貌和红外透过率。结果表明:所制备的AlON透明陶瓷样品未发现杂质相,且晶界处未见明显的玻璃相,晶粒间为直接结合。AlON陶瓷样品的体积密度为3.69g/cm3,约为其理论体积密度的99.5%,弯曲强度为304MPa,断裂韧性为2.14MPa·m1/2;3mm厚透明陶瓷样品的红外透过率达81.3%。而气孔、晶界和第二相杂质等是影响AlON陶瓷透明度的主要因素。

The transparent aluminum oxynitride （Al23O18N5,AlON） ceramics were prepared by hot-press sintering in nitrogen atmos-phere at 1 850-1 950 ℃ and 15-25 MPa,using carbothermal reduction synthesized AlON powder as raw material and Y2O3 as sintering additive. The phase composition,morphology and infrared （IR） transmittance of the AlON samples were analyzed by X-ray diffraction,scanning electron microscope and Fourier transform infrared spectroscopy. The results show that there are no impurity phase in AlON ceramic samples,and no obvious glass phase at the grain boundary of crystal grains since the crystal grains are bound di-rectly. The density of AlON is 3.69 g/cm3,about 99.5% of its theoretical density. The bending strength and the fracture toughness of AlON ceramic are 304 MPa and 2.14 MPa·m1/2,respectively. The IR transmittance of the transparent ceramic sample with 3 mm in thickness is 81.3%. The pores,grain boundaries and second phase in AlON ceramic are the main factors influencing the transmittance of AlON ceramics.