EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

In comparison to their monolithic alternatives, composites of alumina and zirconia are particularly interesting for biomedical applications, thanks to their good mechanical and tribological properties and biocompatibility. The alumina toughened zirconia (ATZ, 80wt. % ZrO2 – 20wt.% Al2O3) was the main consideration as the starting material for this case due to its greater ageing (a.k.a. low thermal degradation) resistance. The focus of this study is the microstructural and mechanical characterization of dense alumina toughened zirconia pieces printed by direct powder-bed selective laser processing method with a commercial 3D Systems Prox200 machine. Commercially available ATZ powder from TOSOH with the addition of 0.75wt. % graphite was used for direct manufacturing. Various combinations of printing parameters were tested in-room atmosphere to obtain an adapted parameter set-up to manufacture ATZ solid parts resulting in a relative density of 96 %. With XRD, no change was observed in the crystalline structure and phases of unprocessed ATZ powder and the PBSL processed pieces. The tetragonal phase of zirconia remained after the process. Surface and cross-section SEM observations were applied to understand the effect of printing strategies. Compression and bending tests were carried out to study the effect of parameter changes like printing direction, hatch distance, etc. The study shows an adapted direct SLPBP set-up to obtain mechanically resistant ATZ pieces with good dimensional accuracy and the structural and microstructural properties will be discussed.