凝胶3D打印制备细晶氧化铝陶瓷研究

Preparation of Fine-Grained Alumina Ceramics by Gel 3D Printing

本文采用溶胶-凝胶法制备了适用于直写打印的拟薄水铝石凝胶,通过改变拟薄水铝石含量以及羟乙基纤维素含量来调控凝胶的流变性,并评价了凝胶的打印性能。针对凝胶坯体干燥所面临的挑战,创新性地提出了多步液相介质干燥方法,采用低分子量聚乙二醇作为干燥介质,乙酸乙酯作为萃取剂,在26 h内实现了厚度为10 mm的凝胶坯体的干燥,并且有效地避免了干燥缺陷的产生,这是传统的低温高湿干燥方法所难以实现的。常压烧结后,成功制备出了平均晶粒尺寸约为1.5μm、相对密度为99%、弯曲强度为(351±53)MPa的致密氧化铝陶瓷零件。

In this paper,a boehmite gel suitable for direct ink writing was prepared by sol-gel method.Rheological properties of the gel were adjusted by changing the content of boehmite and the content of hydroxyethyl cellulose,the printing properties of the gel were evaluated.Multi-step liquid phase drying method was innovatively proposed to tackle the challenges faced by the drying of gel body.Low molecular weight polyethylene glycol was used as the drying medium and ethyl acetate as the extractant,the gel body with a thickness of 10 mm was dried within 26 h,avoiding the occurrence of drying defects,which is difficult to achieve by the traditional low temperature and high humidity drying method.A dense alumina ceramic part with an average grain size of 1.5μm,a relative density of 99%,and a bending strength of(351±53)MPa is successfully prepared after normal pressure sintering.