3D打印氧化铝陶瓷的气氛脱脂热处理工艺研究

脱脂热处理工艺对于3D打印陶瓷的成形质量具有重要的影响。目前光固化3D打印制备得到的氧化铝生坯经过在空气中的脱脂热处理工艺后烧结最终得到的氧化铝陶瓷存在的微观裂纹等缺陷, 将导致其力学性能较差。本工作研究了基于数字光处理(Digital light processing, DLP)技术的氧化铝陶瓷打印热处理工艺, 将3D打印制备得到的氧化铝陶瓷生坯分别在空气与氩气中脱脂后比较其宏观形貌, 发现在空气下脱脂的氧化铝生坯存在微观裂纹。再将脱脂后的生坯在空气下烧结得到氧化铝陶瓷, 并对其微观形貌和宏观性能进行表征, 发现在氩气下脱脂的氧化铝陶瓷平均晶粒尺寸要比直接在空气中脱脂得到的氧化铝陶瓷平均晶粒尺寸大, 而且晶粒结构致密, 无明显气孔和杂相, 而且具有更高的抗压强度。这说明在氩气中脱脂后烧结得到的氧化铝陶瓷性能更好。在氩气中脱脂的氧化铝致密度最高可达到96.72%, 抗压强度可达到761.7 MPa, 相比于只在空气中脱脂的氧化铝陶瓷性能得到显著提升。

Atmosphere Debinding Heat Treatment of 3D Printed Alumina Ceramics

Debinding heat treatment process play an important role in forming quality of 3D printing ceramics. At present, the alumina green body prepared by light curing 3D printing is sintered after debinding in air. The final alumina ceramics may have defects such as micro cracks, resulting in poor mechanical properties. Direct heating and debinding in air may lead to cracks caused by reaction between resin and oxygen in green body. To avoid this situation, this work studies the printing heat treatment process of alumina ceramics based on digital light processing (DLP) technology. The alumina ceramic green body prepared by 3D printing was degreased either in air or in argon, and their macro morphologies were compared with each other. It is found that there are micro cracks in the alumina green body debinding in air. After being sintered in air, the alumina ceramics was obtained and their micro morphology and macro properties were characterized. Average grain size of alumina ceramics debinding in argon was larger than that directly debinding in air, while the grain structure was dense without obvious pore and impurity. Moreover, in terms of mechanical properties, alumina ceramics debinding in air have higher compressive strength. The highest density of alumina debinding in argon reaches 96.72%, and the compressive strength reaches 761.7 MPa, significantly improved as compared with the one debinding in air.