磷酸钙添加量对陶瓷显微组织结构的影响

Effect of Ca3(PO4)2 Content on the Microstructure of Ceramics

为降低陶瓷烧成温度,向传统陶瓷坯料中引入磷酸钙(Ca3(PO4)2),利用X射线衍射仪(XRD)和扫描电镜(SEM),研究不同Ca3(PO4)2含量(2 wt%、4 wt%、6 wt%、8 wt%)对陶瓷显微组织结构的影响.XRD分析结果表明,添加磷酸钙,瓷坯中出现了新相钙长石;增加磷酸钙含量,主晶相中钙长石和莫来石相对含量之和先增后略减,6 wt%时达到最大值19.1%.SEM分析结果显示,引入磷酸钙后,针状钙长石同莫来石纳米晶须呈网状交联一起.在1 220℃下,添加6 wt%磷酸钙,样品抗弯强度达到最大值89.7 MPa.这表明,向坯料中引入适量磷酸钙,在较低温度下可改变陶瓷的晶相组成,优化显微组织结构,有利于提高瓷坯抗弯强度.

In order to decrease the firing temperature of ceramics,calcium phosphate(Ca3(PO4)2)was introduced.The effect of Ca3(PO4)2 content(2 wt%,4 wt%,6 wt%,8 wt%)on ceramic microstruc⁃ture was studied using a Xray diffractometer(XRD)and a scanning electron microscope(SEM).The XRD result indicated that the new phase(anorthite)appeared with the addition of Ca3(PO4)2;with the increase of Ca3(PO4)2,the total content of anorthite and mullite increased first and then de⁃creased slightly.The SEM analysis suggested that with the addition of Ca3(PO4)2,needlelike anor⁃thite and nanosized mullite crystals were crosslinked with each other in the samples.At 1220°C,the bulk density of the sample increased;the flexural strength reached a maximum value of 89.7 MPa at 6 wt%Ca3(PO4)2.This implies that the addition of Ca3(PO4)2 at a lower temperature can change the crystal phase composition,optimize the microstructure,and improve the flexural strength of ceramics.