TiO_(2)加入量对铝镁质干式捣打料性能的影响

Effect of TiO_(2) Content on Performences of Aluminum Magnesium Dry Ramming Materials

以电熔白刚玉、电熔镁砂、活性Al_(2)O_(3)微粉为主要原料,以TiO2为烧结剂,分别在1300℃、1400℃、1500℃和1600℃热处理3 h制备铝镁质干式捣打料。研究了TiO_(2)加入量、热处理温度对捣打料物相、烧结性能、力学性能及显微结构的影响。结果表明,适量TiO_(2)的引入能显著促进铝镁质干式捣打料的反应烧结,常温和高温力学性能均得到明显改善。其烧结性能强化的原因主要是镁铝钛相的形成及TiO_(2)掺入尖晶石晶格形成阳离子空位。当TiO_(2)添加量为0.5%(质量分数)时,经1600℃热处理3 h制得的干式捣打料具有良好的综合性能,此时线膨胀率为3.7%,体积密度和显气孔率分别为2.76g·cm^(-3)和26.6%,耐压强度为18.9 MPa,高温抗折强度(HMOR)为1.9MPa。当TiO2加入过多时,捣打料会出现过烧现象,产生较大收缩,对材料的体积稳定产生不利影响。

Aluminum magnesium dry ramming materials were prepared through heat treatment at 1300℃,1400℃,1500℃and 1600℃for 3 h,using fused white corundum,fused magnesia,reactive Al_(2)O_(3) powder as main raw materials,and TiO_(2) as clinkering aid.The effects of TiO_(2) content,sintering temperature on the phase composition,sintering properties,mechanical properties and microstructures of aluminum magnesium dry ramming materials were investigated.The results show that the introduction of moderate amount of TiO_(2) significantly promotes the reaction sintering of aluminum magnesium dry ramming materials,the mechanical properties both at normal and elevated temperatures are improved obviously.The strengthening of sintering performance is attributed to the formation of magnesium aluminum titanium phase and cation vacancy caused by the incorporation of TiO_(2) into spinel lattice.Good comprehensive properties are obtained after heat treatment at 1600℃for 3 h when the TiO2 content is 0.5%(mass fraction).At this time,the liner change rate is 3.7%,the bulk density and the porosity is 2.76 g·cm^(-3) and 26.6%respectively,the cold crushing strength is 18.9 MPa,and the HMOR is 1.9 MPa.When the content of TiO2 is excessive,aluminate magnesium spinel materials show a large shrinkage as a result of excessive sintering,which is not conducive to the volume stability of the materials.