Influence of several binders on the mechanical properties of alumina parts manufactured by 3D inkjet printing

Inkjet printing is a fast, flexible, highly reproducible, and cost effective manufacturing technology that allows the production of both simple and complex 3D geometries from Computer-Aided Design (CAD) data without the requirement of extra tooling. In this work, we studied the influence of different binders (polyvinyl alcohol (PVA), polyvinyl acetate (PVAc) and arabic gum) on the mechanical and porosities properties of ceramics alumina (Al 2 O 3 ) parts manufactured via 3D inkjet printing. Green specimens were printed using Al 2 O 3 powder as a precursor material and PVA, PVAc and arabic gum suspensions as binder. Green samples were sintered at 1200 °C–1500 °C for 1 h. The microstructure and porosity of sintered samples were evaluated by scanning electron microscope (SEM). Apparent porosity, apparent density and water absorption were measured and the influence of the binders on the compressive behavior was investigated. Results showed that the compositions with best geometric format and mechanical strength were those with polyvinyl alcohol and arabic gum. These specimens showed superior values of apparent densities, lowest porosities, presenting pore size of ≈12 μ m, and compression strength of ≈25 MPa.