Abstract:

Nozzle plate samples for aluminum strip continuous casting and rolling were prepared using aluminum silicate ceramic fiber,kaolin and aluminum tripolyphosphate as main raw materials,silica sol or silica sol-epoxy resin as the bonding system,pulping,casting,curing at different temperatures (25,30,35,40,45,50 and 60 ℃) for different durations (40,60,90 and 120 min),drying at 120 ℃ and heat-treating at 800 ℃.The migration thickness of silica sol and the cold modulus of rupture were measured,and the microstructure was analyzed.The results show that:1)with the same curing temperature,the thickness of the silica sol migration layer of the samples with the different combination systems decreases with the increase of the curing time;with the same curing duration,it basically decreases first and then increases with the increase of the curing temperature;the optimal curing condition is at 40 ℃ for 120 min;2)the silica sol-epoxy composited bonded samples have thinner silica sol migration layers and lower cold modulus of rupture than the silica sol self-curing bonded samples;3)the silica sol-epoxy resin complicated bonded system has better machinability but slightly lower mechanical strength than the silica sol self-gel system.

Key words: silica sol, aluminum silicate ceramic fiber, integral casting nozzle, thickness of migration layer, modulus of rupture

摘要：

以硅酸铝陶瓷纤维、高岭土、三聚磷酸铝等为主要原料,分别以硅溶胶和硅溶胶-环氧树脂为结合体系,经制浆、浇注成型后,在不同温度(分别为25、30、35、40、45、50和60 ℃)下保温不同时间(分别为40、60、90和120 min)进行固化,再经120 ℃干燥和800 ℃热处理,制成连铸连轧铸嘴材料试样,然后检测试样的硅溶胶迁移层厚度和常温抗折强度,并分析其显微结构。结果表明:1)在固化温度相同时,不同结合体系试样的硅溶胶迁移层厚度均随固化时间的延长而减小;在固化时间相同时,不同结合体系试样的硅溶胶迁移层厚度基本上随固化温度的升高而呈先减小后增大的变化趋势;总体来看,以40 ℃固化120 min的固化条件为佳。2)硅溶胶-环氧树脂复合结合试样的硅溶胶迁移层厚度和常温抗折强度均比硅溶胶自固化结合试样的小。3)硅溶胶-环氧树脂复合结合体系比硅溶胶自凝胶体系得到的材料可加工性能优越,但前者的力学强度将略低于后者。

关键词: 硅溶胶, 硅酸铝陶瓷纤维, 整体式铸嘴, 迁移层厚度, 抗折强度