低温制备≥99.5%多晶氧化铝陶瓷(英文)

Preparation for ≥99.5% Polycrystal Alumina Ceramics at Low Temperature

本文通过引入稀土氧化物Y2O3、Tm2O3为烧结助剂低温制备了氧化铝含量大于99.5%的多晶氧化铝陶瓷。实验表明:稀土氧化物的加入能够明显降低99.5%多晶氧化铝陶瓷的烧结温度,提高致密度。Y2O3、Tm2O3混合烧结助剂与单一稀土氧化物的烧结助剂相比能够明显抑制晶粒的生长,促进晶粒的均匀发育。当Y2O3+Tm2O3的含量为0.3%质量分数时,99.5%多晶氧化铝陶瓷的相对密度可达99.2%理论密度,抗弯强度为533MPa,显微硬度为17.2GPa。陶瓷断裂主要以穿晶断裂为主。

The polycrystal ceramics with the content of alumina more than 99.5wt% were prepared by sintering at low temperature with rare earth oxide Y2O3 and Tm2O3 as sintering aids. Addition of Y2O3 and Tm2O3 in the alumina powders decreased the sintering temperature and improved the relative density effectively.Compared to monolithic alumina ceramics and alumina ceramics with single rare earth oxide addition,the mixture, Y2O3＋Tm2O3, can restrain the growth of grains, and make the size of grains uniform, and finally form a compact structure. The trans-granular fracture is the main fracture mode for the polycrystal alumina ceramics with Y2O3 ＋ Tm2O3. The size of grains is from 3 to 5μm, and the maximum bending strength is 533MPa, hardness is 17.2GPa.