基于冷冻铸造法制备二氧化钛多孔陶瓷

Titanium Dioxide Porous Ceramics Prepared with Freeze Casting

以冷冻铸造法制备TiO_(2)多孔陶瓷为背景,研究了冷冻速率、浆液浓度以及冷冻方式对TiO_(2)多孔陶瓷微观结构和力学性质各向异性的调控规律。结果表明:随着浆液浓度的增大(10vol.%~25vol.%),多孔陶瓷的孔隙率以及平均层间距均减小;冷冻速率主要通过影响冰晶的生长方式改变多孔陶瓷的平均层间距;双向冷冻铸造法制备TiO_(2)多孔陶瓷的过程中,随着楔角增大,多孔陶瓷的横截面组织取向性增强。随着浆液浓度和冷冻速率的增大,TiO_(2)多孔陶瓷沿不同方向的维氏硬度和抗压强度整体上均呈增大趋势,但不同方向的增幅不一;随着楔角增大(0°~20°),多孔陶瓷抗压强度的各向异性更加突出,表现在x方向的抗压强度从12.15MPa增至64.91MPa。制备的TiO_(2)多孔陶瓷在生物骨组织材料以及陶瓷过滤器等领域有着较大的应用潜力。

The effects of freezing rate,slurry concentration and freezing method on microstructure and anisotropy of mechanical properties of TiO_(2) porous ceramics were studied.With increasing concentration of slurry(10-25 vol.%),both porosity and average interlayer spacing of the porous ceramics were decreased.The freezing rate mainly affects the average interlayer spacing by varying the growth mode of ice crystals.In the bidirectional freezing casting process,cross-sectional orientation of the porous ceramics tends to be more consistent with increasing wedge angle.With increasing slurry concentration and freezing rate,the Vickers hardness and compressive strength of the TiO_(2) porous ceramics in different directions are increased as a whole,but the increase degree in different directions is different,as the wedge angle increases(0°-20°)and the anisotropy of the compressive strength of the porous ceramics becomes more prominent,which is increased from 12.15 to 64.91 MPa in x direction.The TiO_(2) porous ceramics have great application potential in the fields of biological bone tissue materials and ceramic filters.