| In this paper, based on silica sol ceramic cracking and gel mechanism, it adopted ceramic type mixing fiber and changing slurry cementing technology, improved silica sol ceramic cracking resistance and gel time, studied the effect of fiber on tensile strength and shrinkage of ceramic, solved ceramic cracking problem and provided a theoretical basis and practical foundation.In the paper, the tensile strength values of the samples were tested by XQY-II intelligent sand strength machine. The shrinkage rate of ceramic mould was tested by Accuracy of0.1mm digital display vernier caliper. The morphology of the glass fiber set in ceramic was observed by S-3400N scanning electron microscopy. The gel speed of the ceramic slurry was tested by the homemade needle penetration tester. The effect of fibers on viscosity was analysized by using NDJ-1rotating viscometer.The tensile strength analysis displayed that the wet strength of silica sol ceramic mould increased with the time prolonged. The strength values of with fibers were improved significantly with the increasing of the fiber contents. When a certain amount(0.12vol%) of aluminum silicate fiber and glass fiber was separately added, with the temperature increasing, the tensile strength values were improved significantly over those without fibers. The tensile strength of ceramic mould increased with the increasing of the fiber contents. In the research, when0.24vol% aluminum silicate fiber and glass fiber was separately dispersed into the ceramic mould, the strength values were improved the maximum, which increased respectively by34.9% and25.7%. The shrinkage rate analysis results confirmed that the shrinkage rate of ceramic mould first increased, and then decreased with the sintering temperature rising, the rate was maximum at500℃. The ceramic mould with fiber dispersion had lower shrinkage rate than that without fiber at all sintering temperature. The cracking trend of the ceramic mould was dramatically reduced with fiber contents, and the trend could be increased with the increasing of the fiber content. Within certain fibers content range(0-0.24vol%) in this study, when0.24vol%glass fiber and aluminum silicate fiber was separately dispersed into the ceramic mould, the maximum improvement of cracking resistance reaches23.2%and28.8%after sintered.The needle penetration values analysis results indicated that the gel speed was decreased with the increasing of thickness of slurry. When pressure was0.1MPa, the temperature was prominent to gel speed,60℃was optimum temperature. The pressure was obvious to gelling speed at room temperature, the best pressure value for-0.01MPa.In the article, the cracking resistance of the fiber reinforced silica sol ceramic mould was analyzed based on the basic theory of composite materials. In addition, the process variables affected gel speed, which was also analyzed by gelling mechanism. |
