基于激光选区烧结的煤系高岭土多孔陶瓷的制备及其性能

Preparation and Properties of Porous Coal-series Kaolin Ceramics by Selective Laser Sintering

以煤系高岭土为原料,采用激光选区烧结(SLS)技术制造复杂结构的多孔陶瓷,研究SLS工艺参数和烧结温度对煤系高岭土多孔陶瓷性能的影响。利用X射线衍射仪(XRD)和扫描电子显微镜(SEM)表征煤系高岭土多孔陶瓷的物相组成和显微形貌。结果表明:煤系高岭土/环氧树脂E12复合粉末SLS成型效果良好;当激光功率为5W,扫描速率为2000mm/s,扫描间距为0.13mm,单层层厚为0.15mm时,陶瓷素坯可获得最佳的成型质量,其尺寸误差(Z方向),相对密度和抗弯强度分别为10.43%,37.89%和0.984MPa。随着烧结温度的升高,煤系高岭土多孔陶瓷的收缩率和抗弯强度逐渐增大,而显气孔率则逐渐减小;当烧结温度为1450℃时,煤系高岭土多孔陶瓷具有较高的显气孔率和抗弯强度,分别为44.55%和6.1MPa。煤系高岭土多孔陶瓷的主晶相为莫来石,具有典型的三维网络骨架结构。

Porous ceramics with complex structure were prepared by selective laser sintering（SLS）method using coal-series kaolin as raw materials.The effect of SLS process parameters and sintering temperature on properties of porous coal-series kaolin ceramics was investigated.The phase composition and microstructure of porous coal-series kaolin ceramics were characterized by X-ray diffractometer（XRD）and scanning electron microscope（SEM）.The results indicate that the coal-series kaolin/E12 composite powders can be formed well through SLS method.The green bodies show the superior quality.Zdirection error is 10.43%,relative density is 37.89% and bending strength is 0.984 MPa under laser power of 5 W,scanning speed of 2000 mm/s,scanning space of 0.13 mm and layer thickness of 0.15 mm.With the increase of sintering temperature,the linear shrinkage and bending strength of the porous coal-series kaolin ceramics increase gradually,while the open porosity decreases.The porous coal-series kaolin ceramics possess a high open porosity of 44.55%and a good bending strength of 6.1 MPa when the sintering temperature is 1450℃.The main phase in the prepared porous ceramics is mullite phase,and they have a typical three-dimensional skeleton structure.