添加氧化钙的硅酸锆陶瓷的性能

以硅酸锆和硝酸钙为原料,采用湿磨的方法实现原料的均匀混合,制备了系列的添加氧化钙的硅酸锆陶瓷,利用阿基米德法和X-射线衍射技术对硅酸锆陶瓷的密度、物相变化进行了表征,测试了其显微结构和抗折强度,重点讨论氧化钙添加量和烧成温度对硅酸锆陶瓷的影响.结果表明,1 450℃和1 500℃烧结试样的体积密度随氧化钙添加量改变有较小变化,1 550℃烧结试样密度则随着氧化钙添加量增大而减小,密度最大值可达4.19克/立方厘米;样品的物相由硅酸锆和单斜氧化锆及少量稳定氧化锆组成,主晶相为硅酸锆;硅酸锆陶瓷有较多的气孔,是其致密度小的主要原因,硅酸锆陶瓷的主要断裂方式是沿晶断裂;硅酸锆陶瓷的抗折强度随着烧成温度的升高明显降低,随氧化钙添加量增大而先减小再增大,抗折强度最高可达186.0兆帕.

Performance of zirconium silicate ceramic dopped calcium oxide

To mix the raw materials completely,a series of zirconium silicate ceramic dopped calcium oxide were prepared by wet milling,using zirconium silicate and calcium nitrate as the raw material.The phases of the sintered samples were characterized by X-ray diffraction,and the density was calculated by Archimedes method.We also measured the microstructures and the rupture strength.The influence of calcium content and sintering temperature on zirconium silicate ceramic was also discussed.The results show that,as the additive amount of the calcium oxide increasing,the volume density has a little change in the samples which were sintered respectively at 1 450 ℃ and 1 500 ℃,but decreasing in which were sintered at 1 550 ℃ ;the maximum of the volume density can reach 4.19 g/cm3 ; all samples consist of zirconium silicate,monoclinic zirconia and a little stabilized zirconia.The principal crystal phase is zirconium silicate;zirconium silicate ceramic has more pores,which is the main reason of its small density; the main fracture mode of zirconium silicate ceramic is the intergranular fracture; as the sintering temperature increasing,the rupture strength decreases significantly; when the additive amount of the calcium oxide increasing,the rupture strength first decreases to a degree and then rises,and the maximum of the rupture strength can reach 186.0 MPa.