Additive manufacturing of complexly shaped SiC with high density via extrusion-based technique – Effects of slurry thixotropic behavior and 3D printing parameters. Issue 19 (1st October 2022)

• Record Type: Journal Article
• Authors: Chen, Ruoyu; Bratten, Adam; Rittenhouse, Joshua; Huang, Tian; Jia, Wenbao; Leu, Ming C.; Wen, Haiming
• Is Part Of: Ceramics international. Volume 48:Issue 19(2022)Part A
• Page Start: 28444
• Page End: 28454
• Publication Date: 2022-10-01
• Subjects: Additive manufacturing -- Silicon carbide -- Rheological behavior -- Printing parameters -- Machine learning; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.06.158
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Additive manufacturing of dense SiC parts was achieved via an extrusion-based process followed by electrical-field assisted pressure-less sintering. The aim of this research was to study the effect of the rheological behavior of SiC slurry on the printing process and quality, as well as the influence of 3D printing parameters on the dimensions of the extruded filament, which are directly related to the printing precision and quality. Different solid contents and dispersant- Darvan 821A concentrations were studied to optimize the viscosity, thixotropy and sedimentation rate of the slurry. The optimal slurry was composed of 77.5 wt% SiC, Y2 O3 and Al2 O3 powders, 0.25 wt% dispersant and 0.01 wt% defoamer. The printing parameters studied included extrusion pressure, nozzle size, layer height and printing speed; the one that had the most prominent effect on filament width and height was indicated as layer height. The nozzle inner diameter of 1.04 mm, speed of 350 mm/min, layer height of 0.7 mm and extrusion air pressure of 0.31 MPa were the optimal printing parameters. Furthermore, the relationship between the printing parameters and the filament dimensions was successfully predicted by using machine learning and grey system theory. Finally, the relative density of the printed SiC parts sintered at 1900 o C reached 94.7±1.5%.