【作者】 陈海军；

【导师】 徐恩霞；

【作者基本信息】 郑州大学 ， 材料与化工（专业学位）， 2023， 硕士

【摘要】 氧化铝陶瓷基板的烧成温度在1600℃以上,多采用推板窑烧成。推板砖是推板窑中不可缺少的窑具,起承载和运输窑内制品的重要作用。目前,国内外高温推板窑中常用的推板砖主要是刚玉-莫来石制品。由于推板砖使用温度高,且在高温下承受的应力大,因此使用一段时间后会产生较大变形,从而导致其使用寿命较短。为了提高刚玉-莫来石窑具的高温使用性能,本文以电熔刚玉和电熔莫来石为骨料,以氧化铝和氧化硅微粉为基质料,采用微粉烧结和反应烧结技术制备刚玉-莫来石材料,研究原料组成和工艺因素对其烧结性能、显微结构和高温蠕变性能的影响,结果如下:首先研究了颗粒级配和烧成温度对刚玉莫来石材料烧结性能的影响,结果表明,颗粒级配选择粗颗粒（3-1 mm）/中颗粒（1-0 mm）/细粉（≤44μm）=43/25/32,烧成温度选择1700℃。其次研究了基质细粉中氧化铝微粉粒度、氧化硅微粉种类和烧结粘土加入量对刚玉-莫来石材料烧结性能的影响,结果表明,基质细粉中Al₂O₃微粉的粒度≤5μm的比≤44μm的好;三种Si O₂微粉相比,加入硅微粉比改性石英和熔融石英微粉好;采用苏州土为烧结粘土,最佳加入量为1.5 wt%。分别研究了三种天然矿物原料（红柱石、硅线石和锆英石）的添加对刚玉莫来石材料性能的影响。结果表明,添加红柱石和硅线石后,试样烧成线变化率由收缩变为膨胀,试样体积密度降低、显气孔率增加,其中硅线石比红柱石的膨胀更为明显。原位反应生成的粒状和片状莫来石,提高了刚玉-莫来石材料的常温力学性能。添加红柱石使刚玉-莫来石材料的高温蠕变率变大,添加硅线石的刚玉-莫来石材料高温抗蠕变性能较好。在刚玉-莫来石材料中添加锆英石后,试样的体积密度变大,显气孔率减小;随着添加量的增加,耐压强度呈现先降低后增加的趋势。在刚玉-莫来石材料中添加锆英石后,试样的抗蠕变性能显著下降。通过本课题的研究,采用电熔刚玉和电熔莫来石为骨料,刚玉细粉、粒度≤5μm的氧化铝微粉和硅微粉为基质,加入1.5%的苏州土作为烧结粘土;通过150MPa压力成型、1700℃高温烧成制备刚玉-莫来石材料,该材料的体积密度为2.96 g/cm³,显气孔率16.1%,常温耐压强度54.8 MPa,1600℃、25小时的蠕变率为0.05%。更多还原

【Abstract】 Alumina ceramic substrate firing temperature is above 1600℃,which mostly happen in push-plate kiln.Push-plate brick is an indispensable kiln furniture in push-plate kiln,which plays an important role in carrying and transporting products.At present,corundum-mullite products are commonly used in high temperature push-plate kilns at home and abroad.Due to the high use temperature and high stress of push plate brick,it leads to short service life.the failure reason is mainly caused by large deformation after use at 1600℃for a period of time.In order to improve the high temperature performance of corundum-mullite kiln furniture,this paper prepared corundum-mullite materials by micro-powder sintering and reactive sintering technology with fused corundum and fused mullite as aggregate and alumina and silica powder as matrix materials,and studied the effects of raw material composition and technological factors on sintering properties,microstructure and high temperature creep properties.The results are as follows:Firstly,the effects of particle composition and sintering temperature on the sintering properties of corundum-mullite materials were studied.The results show that the particle composition is coarse particle（3-1 mm）/medium particle（1-0 mm）/fine powder（≤44μm）=43/25/32,and the sintering temperature is 1700℃.The effects of alumina powder size,silica powder type and sintered clay content on the sintering properties of corundum-mullite materials were investigated.The results show that the particle size ofα-Al₂O₃ powder≤5 micron is better than that ofα-Al₂O₃powder≤44 micron.Compared with the three kinds of Si O₂micropowder,adding Elkem microsilica is better than modified quartz and fused quartz micropowder.Suzhou clay was used as sintered clay,and the optimum addition amount was 1.5%.The effects of three natural mineral materials（andalusite,sillimanite and zircon）on corundum-mullite materials were studied.The results show that with the addition of andalusite and sillimanite,the change rate of fired line changes from contraction to expansion,the bulk density decreases and the apparent porosity increases,and the expansion of sillimanite is more obvious than that of andalusite.The mechanical properties of corundum-mullite at room temperature were improved by in-situ reaction of granular and flake mullite.The addition of andalusite increases the creep rate at high temperature,and the addition of sillimanite increases creep resistance at high temperature.When zircon is added to corundum mullite,the bulk density of the specimen increases and the apparent porosity decreases.With the increase of the addition amount,the compressive strength showed a trend of decreasing first and then increasing.The addition of zircon decreases significantly creep resistance at high temperatureIn this study,fused corundum and fused mullite were used as aggregate,corundum fine powder,alumina fine powder with particle size≤5 microns and silica fine powder were used as matrix,1.5%Suzhou clay was added as sintered clay.Corundum mullite material was prepared by 150 MPa pressure molding and high temperature sintering at1700℃.The bulk density of the material was 2.96 g/cm³,the apparent porosity was16.1%,the compressive strength was 54.8 MPa at room temperature,and the creep rate was 0.05%at 1600℃for 25 hours.更多还原