添加氟化物对硅灰石玻璃陶瓷性能的影响

Effect of Fluoride on Properties of Wollastonite Glass Ceramics

以钙铝黄长石、废玻璃粉为主要原料,分别添加MgF2、BaF2及复合氟化物,用反应析晶烧结法制备硅灰石玻璃陶瓷。使用X射线衍射(XRD)、扫描电子显微镜(SEM)对样品的物相和形貌进行表征。对添加不同氟化物制备的硅灰石玻璃陶瓷进行了密度、收缩率、气孔率、吸水率、抗弯强度、抗压强度等性能测试。结果表明,添加MgF2、BaF2或复合氟化物制备的玻璃陶瓷主晶相均为硅灰石。添加MgF2可促使硅灰石玻璃陶瓷大量析晶,密度较低,吸水率和气孔率均较高,抗压强度大大降低。添加BaF2或复合氟化物具有较低的吸水率和气孔率,较高的密度,以及较高的抗弯强度和抗压强度。添加复合氟化物后可通过玻璃陶瓷的自收缩作用实现其烧结致密化,当添加5%MgF2与5%BaF2后,制得的硅灰石玻璃陶瓷体积密度2.432 2 g/cm^3,相对密度90.93%,气孔率0.27%,吸水率0.06%,抗弯强度54 MPa,抗压强度239 MPa。

The wollastonite glass ceramics were prepared by reaction crystallization sintering method with gehlenite and waste glass powder as main raw materials,respectively adding MgF2,BaF 2 and complex fluorides.The phase structure and morphology of the samples were characterized by X-ray diffraction(XRD)and scanning electron microscope(SEM).The density,shrinkage,porosity,water absorption rate,flexural and compressive strength of wollastonite glass ceramics were tested.The results show that all the main crystalline phase of the glass ceramics prepared by adding MgF 2,BaF 2 and complex fluorides is wollastonite.The wollastonite glass ceramics with MgF 2 promotes a large number of crystallization of wollastonite glass ceramics.It has low density,high water absorption rate and porosity,and greatly reduce its compressive strength.The wollastonite glass ceramics with BaF2 or complex fluorides have lower water absorption rate and porosity,higher density,higher flexural and compressive strength.The sintering densification of glass ceramics can be realized by the self-shrinkage after adding complex fluorides.When 5%MgF 2 and 5%BaF2 are added,the bulk density of wollastonite glass ceramics is 2.4322 g/cm^3,relative density is 90.93%,porosity is 0.27%,water absorption rate is 0.06%,flexural strength is 54 MPa and compressive strength is 239 MPa.