薄带连铸用BN基侧封板材料的性能研究及应用

Properties and application of BN based side dam materials for thin strip continuous casting

为了开发适合用于薄带连铸生产的侧封板材料,以h-BN为主要原料,采用热压烧结工艺于1 800℃制备了BN-Si C-Zr O2系、BN-Si3N4系以及BN-Mg Al2O4系三种BN基复合材料,并测试和分析了烧结试样的力学性能、热性能、物相组成、显微结构以及薄带连铸效果。结果表明:最佳侧封板试样为1 800℃热压烧结的BNSi3N4系试样,其抗折强度为260.3 MPa,维氏硬度为343.5 kg·mm-2,热膨胀系数为2.8×10-6℃-1,1 100℃水冷热震次数>30次;XRD分析显示其主要晶相是h-BN、β-Si3N4以及Si Al ON相,SEM观察显示试样中晶体均被Si Al ON相包裹。薄带连铸试验显示,开发的BN-Si3N4系侧封板试样的耐磨性能及抗侵蚀性能均优于熔融石英质侧封板的。

Three boron nitride （BN） based composites （ BN-SiC-ZrO2, BN-Si3N4, and BN-MgAl2O4） were prepared with h-BN as the main staring material by hot-pressing at 1 800 ℃. The mechanical properties, thermal properties, phase composition,microstructure and thin strip continuous casting property were tested and analyzed. The results indicate that the best side dam material is BN-Si3N4 sintered at 1 800 ℃; it achieves the bending strength of 260.3 MPa,the Vickers hardness of 343.5 kg·mm^-2,the thermal expansion coefficient of 2.8 × 10^-6℃-1 ,and shows no crack after thermal shock for 30 times from 1 100 ℃ to water quenching. XRD analysis indicates that the main crystal phases are h-BN,β-Si3N4 and SiAION. SEM studies show that the crystal grains are wrapped up by SiAION. The thin strip continuous casting result indicates that the side dam specimen BN-Si3N4 has better wear resistance and corrosion resistance than the fusion quartz side dam.