氧化铝空心球陶瓷断裂机制研究

Study on fracture mechanism of alumina bubble ceramic

为进一步提高轻质氧化铝空心球陶瓷的质量和使用寿命,采用急冷急热和机械作用的方式对不同结合剂结合氧化铝空心球陶瓷的破损机理进行深入的研究,发现氧化铝空心球陶瓷的破坏特性与所受的应力特性和结合剂种类有关.研究结果表明,在机械应力作用下,断裂方式取决于陶瓷抗折强度,高抗折强度为穿球断裂,低抗折强度以沿球断裂为主;在热震应力作用下,断裂方式与结合剂种类有关,铝胶原位分解形成纳米γAl2O3助烧结结合以沿球断裂为主,磷酸原位反应生成磷酸铝结合以穿球断裂为主.

To further improve the quality and service life of alumina bubble ceramic, the fracture mechanism of alumina bubble ceramic combined with different binder was studied by thermal shock stresses and mechanical stresses method. The results reveal that the fracture of alumina bubble ceramic relies greatly on the variety of binder and stresses behavior. Under mechanical stresses, trans-ball fracture happens with high flexural strength alumina bubble ceramic while along-ball fracture mainly happens with low flexural strength alumina bubble ceramic. Under thermal shock stresses, alumina bubble ceramic sintered through in-situ decomposition to nano-meter γ-Al2O3 show along-ball fracture, the sintered alumina bubble ceramic show trans-ball fracture because of in-situ formation of aluminum orthophosphate.