Development of Alumina Based Feedstock For Fused Deposition Modelling 3D Printer

• Main Author: Tan, Roe Djer
• Format: Final Year Project / Dissertation / Thesis
• Published: 2020
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://eprints.utar.edu.my/4113/1/1505057_fyp_report_%2D_ROE_DJER_TAN.pdf; http://eprints.utar.edu.my/4113/

Alumina is ceramics with excellent properties such as chemical inertness, high hardness, and thermal stability. However, alumina product forming process like powder metallurgy, casting, and plastic forming could be troublesome as alumina shape manipulation is inflexible. Integration of additive manufacturing (AM) with alumina formulation is a potential game changer that revitalize the alumina forming industry due to flexibility and customizability of AM. In fact, there have been studies done regarding to alumina 3D printing. However, question still remain on the development of alumina-based feedstock for fused deposition modelling (FDM) 3D printing due to very few studies in this sector. Therefore, alumina-based feedstock for FDM 3D printer was developed and investigated in this study. The in-depth understandings provided in this study could guide the alumina manufacturing industry in formulation of complex shape alumina such as body armour as well as rapid alumina prototyping. This work was initiated with doping of 1 wt% Titanium dioxide (TiO2) into alumina powder to reduce the sintering temperature of alumina. Cellulose acetate (CA) as a binder was then mixed with acetone with concentration of 100 g/L, 150 g/L, and 200 g/L to form a transparent solution. The transparent solution was mixed with alumina powder with binder-solvent volume occupation up to 90 vol% to form a slurry. It was followed by preparation of green samples from the slurry and they were debinded and pressureless sintered at 1400 ºC for an hour. Characteristic tests were done to determine the flow curve of the slurries as well as the bulk density and the hardness of the sintered samples. X-ray diffraction (XRD) and microstructure analyses were conducted to further reflect the properties of the samples. Sample prepared by CA-acetone concentration of 200 g/L with 80 vol% binder exhibited the highest bulk density of 2.963 g/cc (75 % relative density), the highest microstructural compaction, and appropriate slurry viscosity as required by FDM. As a result, it is feasible to apply alumina-based feedstock with CA as binder in FDM 3D printer.