The Primary Investigation Of Using β-Si₃N₄ In Aqueous Gel-casting

Silicon nitride ceramics is a sort of material of high temperature and high intensity structure which have been developed since 1950s.In virtue of excellent high temperature mechanical properties and chemical stablility,it plays an important part on modern-time manufacturing.Gel-casting technique is a near-net-shape forming technics of ceramics material developed in the recent years.It is regarded as the most promising process for the ceramic parts of high chemical purity and complex shape.The key point in gel-casting technology are high uniformity,high stability,high solid loading and drying system. According to the study on surface electromotion capability and slurry rheological property of the power as well as green pieces drying method,educe hereinafter perorate:1.Monomer AM of aqueous gel-casting,the slurry rheological property and the sample property is preferable when its adding quantity is 1.7 wt.%;MBAM as association,the slurry rheological property is preferable when its adding quantity is 0.55wt.‰,and the sample property is preferable when its adding quantity is 0.5wt.‰;PAANa as dispersant,the slurry rheological property and the Sample property is preferable when its adding quantity is 0.55wt.‰;APS as solicitation,the sample property is preferable when its adding quantity is 1.5wt.‰.2.According to the influences of solid content,pH value,dispersant on the rheological property,Gel-casting slurry of high solid content(50vol.%)and low viscosity (16mPas)is prepared.Slurry show the speciality of inflatable type liquid.3.Green sample are dried in the desiccator at 21.5℃and humidity 55%,drying time is longer,crackle appear on green pieces,pore rate is great.