Preparation of fully dense boron carbide ceramics by Fused Filament Fabrication (FFF)

• Published in: Journal of the European Ceramic Society Vol. 43; no. 5; pp. 1751 - 1761
• Main Authors: Vozárová, Mária, Neubauer, Erich, Bača, Ľuboš, Kitzmantel, Michael, Feranc, Jozef, Trembošová, Veronika, Peciar, Peter, Kritikos, Michaela, Orlovská, Martina, Janek, Marián, Matejdes, Marián
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2023
• Subjects: Additive manufacturing; Boron carbide shaping; Fused filament fabrication (FFF); Fused filament fabrication (FFF); Boron carbide shaping; Additive manufacturing
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2022.12.018

Boron carbide is the third hardest material known, with a high melting point (2450 °C) and poor sintering ability. Therefore, boron carbide is a challenging material for shaping by conventional processing routes and can still be considered as unsuitable for commercial production of ceramics parts by additive manufacturing technologies. This work reports the first successful preparation of boron carbide ceramics fabricated by fused filament fabrication from a newly developed composite filament containing 65 wt% of micron-sized boron carbide powder dispersed in a thermoplastic binder. A commercial FFF desktop printer with a 0.40 mm nozzle was used for manufacturing of complex-shaped green bodies. Almost fully dense boron carbide ceramics with printed parts sized up to 4 centimeters and relative density higher than 96% after sintering were prepared. The DTA/TG analysis of composite filament and heat microscopy technique were used to set the debinding temperature program with critical temperature at 140 °C, due to the thermal decomposition of the binder. Microstructure SEM images after sintering showed excellent material homogeneity, while micro-CT images showed very well retained experimental shapes of collimator-like printed grids. The x-ray diffraction proved the presence of boron carbide phase with the free carbon phase at the level of about 1 wt% without significant influence on the measured hardness value of 29.88 ± 1.27 GPa. •A novel highly filled filament containing the thermoplastic binder and 65 wt% boron carbide powder was successfully developed.•B4C filament was successfully tested on the low-cost desk top 3D-printer.•Complex-shaped boron carbide parts were debinded and sintered without shape collapsing and deformation.•Samples after sintering exhibited excellent relative densities on the level of 96% and very fine microstructure.