片状氧化铝晶种对氧化铝陶瓷结构和性能的影响

Effect of Plate-like Alumina Seeds on Alumina Ceramics

本文以片状氧化铝单晶颗粒为晶种,CaO-Al2O3-SiO2(CAS)为添加剂,研究了晶种加入对氧化铝陶瓷显微结构与性能的影响。研究发现,晶种和CAS的共同作用促进了片状晶粒的生长。随晶种量增加,片状晶粒粒径分布的峰值和径厚比分布的峰值先增后降。晶种加入对氧化铝陶瓷相对密度和硬度影响不大,但断裂强度与断裂韧性随晶种量的增加呈现先增后降的趋势。加入15wt%晶种时陶瓷的断裂强度与断裂韧性达到最大(分别为430MPa与5.78MPa·m1/2),比未加晶种的陶瓷提高了23%与38%。

The effects of plate-like alumina seed additions on the microstructure and properties of alumina ceramics were studied, when plate-like alumina single crystal particles were used as seeds and CaO-Al203-SiO2 （CAS） were used as additives. The additions of both α-Al2O3 platelets and CAS lead to the development of plate-like grains. The peaks of size and aspect ratio of plate-like grains increase first and then decrease with the increase of seed addition. The relative density and hardness of alumina ceramics sintered at high temperatures are hardly affected by the plate-like alumina seed additions, but the flexure strength and fracture toughness increase first and then decrease with the increase of seed addition. When 15% seeds are added, the flexure strength and fracture toughness reach a maximum, and they are 430MPa and 5.78MPa · m^1/2 , respectively. Compared with the sample without the addition of seeds, the flexure strength and fracture toughness increase by 23% and 38%, respectively.