纤维改性陶瓷型芯3D打印及尺寸精度控制

Fiber Modified Ceramic Cores by 3D Printing and Dimensional Precision Control

3D打印技术为复杂形状陶瓷型芯提供了新的制备途径,但其高温尺寸精度受到体积收缩和蠕变变形的严重影响。通过光固化3D打印技术制造了硅基陶瓷型芯,并研究了硅酸铝纤维作为增强相的影响。结果表明,由于打印铺料中的刮刀作用,纤维含量低于4 wt%时,大多数纤维在印刷层内表现出定向分布,降低了抗弯强度。当纤维含量为12 wt%,一些纤维表现出无序分布,穿插在不同层面,从而通过纤维拔出提高了强度。尽管纤维对强度的增强效果不明显,硅酸铝纤维在烧结和铸造中降低了收缩率,并增强了抗蠕变性能,使铸件尺寸精度得到显著提升。

3D printing technology provides new methods for complex-shaped ceramic cores,but its hightemperature dimensional accuracy is severely influenced by volumetric shrinkage and creep deformation.In this work,silicon-based ceramic cores were manufactured via 3D printing through vat photopolymerization,and the effects of aluminum silicate fibers as a reinforcement phase were investigated.Due to the action of the scraper in the printing material,most of the fibers displayed orientation distribution inside the printing layers,which decreased the bending strength as the fiber content was below 4 wt%.At a fiber content of 12 wt%,some fibers showed disordered distribution and were arranged to connect the interlayer cracks,therefore improving the strength by fiber pullout.Although the reinforcement effect of fibers on strength was not obvious,the aluminum silicate fibers reduced the shrinkage rate during sintering and casting,and enhanced the creep resistance,resulting in a substantial improvement in the dimensional accuracy of the castings.