β-SiAlON结合刚玉砖的高温力学性能与显微结构

High temperature mechanical properties and microstructure of β-SiAlON bonded corundum bricks

以常用的刚玉砖和低蠕变高铝砖作对比材料，研究了β-SiAION（包括氧化铝基β-SiAlON和矾土基。β-SiAION）结合刚玉砖的高温力学性能、显微结构特征和断裂特征。结果表明：（1）β-SiAION结合刚玉砖在1400℃时的抗折强度是刚玉砖和低蠕变高铝砖的5倍以上，其塑性变形开始温度和粘滞流动开始温度都较刚玉砖和高铝砖的高200～300℃，在相同条件下，其高温蠕变变形率仅为低蠕变高铝砖的10％-20％；（2）在β-siAlON结合刚玉砖中，主晶相刚玉颗粒构成了砖体的骨架结构，原位生成的β-SiAlON晶体填充于刚玉颗粒的间隙中，与粒状刚玉结合紧密，这种结构特征增强了复合材料的高温力学性能；（3）在1400℃高温下，β-SiAlON结合刚玉砖的断裂方式是以穿颗粒断裂为主的混合断裂。

High temperature mechanical properties, microstructure and fracture characteristics of β-SiAION （ including alumina based β-SiAION and bauxite based β-SiAION） bonded corundum bricks were studied by comparing with conventional corundum bricks and low creep high alumina bricks. The results show that. （1）The HMOR at 1 400 ℃ of 15-SiAION bonded corundum bricks is more than 5 times than that of two compared bricks,temperature of plastic deformation and temperature of viscous flow are 200 -300 ℃ higher than that of two compared bricks,the high temperature creep rate at the same condition is only 10% -20% of that of high alumina bricks; （2）In -SiAION bonded corundum bricks, β-SiAION crystals in-situ formed are well interlaced and interlocked within the main crystal phase corundum skeleton structure, resulting in noticeably strengthening the high temperature mechanical properties;（3）The fracture mode of β-SiAION bonded corundum bricks at 1400 ℃ is mainly transgranular fracture.