The Preparation Of CaO Ceramic And The Study On The Structure And Properties

Calcium oxide ceramics are prepaerd by adding TiO2, ZrO2, MgOandCr2O3 in different sintering temperature. Studing the influence of content of additives and the sintering temperature to the sintering performance of calcium oxide ceramics. Discussing the influence of type and content of additives and the temperature to the hydration resistance performance of CaO ceramic by Themostatic method.Prepaering CaO ceramics using extrusion molding by adding polyvinyl butyral and PEG600 to CaO powder.The study result of influence of additives to CaO ceramic show that:TiO2, MgO Cr2O3 and ZrO2 all can promote the sintering of CaO ceramics. After sintering, the volume density and flexural strength of ceramic increase, and with the increasing of the content of additives, the volume density and the flexural strength of ceramic unceasingly strengthens in the rang of 1%-5% content of additives.When the content of additives is over 3%, the volume density and flexural strength growth smoothly. The hydration resistance performance of CaO ceramic increase significantly after additing additives,and with the increasing of the content of additives, the hydration resistance performance unceasingly strengthens.And with the increasing of sintering temperature, the volume density,the flexural strength and the hydration resistance performance of CaO ceramic enhance.The mechanism of four additives on the improving of hydration resistanc performance of CaO ceramic is:TiO2, ZrO2 and MgO promote the sintering of CaO ceramics by forming solid solution when sintering. The solid solution which is in the near grain boundary, promoting the sintering of ceramic and reducing the pore of ceramic.Also it promotes the grewing up of CaO grains.All these reasons reduc the contact area of CaO and water,then improving the hydration resistance performance of ceramic. And in the three additives,the effect of TiO2 is more obviously than others in the same sintering temperature.But,the Cr2O3 additive promotes the sintering of CaO ceramic by producing liquid.In a lower temperature (less than 1300℃),Cr2O3 and CaO will react and produce a new compound,which have a lower melting point.This liquid compound is not only in grain boundary promoting the sintering of ceramic,but also wrapping in the granular surface preventing the contact of water with CaO grains.Then the hydration resistance performance of ceramic enhance obviously.For four kinds of additives, the reaction between Cr2O3 and CaO produces liquid in a lower temperature, that reduces the high temperature-resistant performance of CaO seriously.MgO and ZrO2 additives need high content and high sintering temperature (more than1,550℃),then can improve the anti hydration performance of CaO ceramic obviously.Then,TiO2 is a good additive for CaO ceramic.Using the polyvinyl alcohol as plasticizers, PEG600 lubricant,TiO2 as additive, preparing CaO ceramic green body by extrusion molding. Sinteing the ceramic body in 1550℃,getting high density CaO ceramic.