Fabrication and Static Bending Properties of 3D Printed Zirconia Part via Digital Light Processing Method

Abstract

Zirconia is widely applied as an implant due to its’ excellent biocompatibility and mechanical properties such as high hardness and extraordinary resistance to wear and corrosion. However, these outstanding mechanical properties make it challenging to fabricate Zirconia into complex shapes using conventional manufacturing techniques. In the current study, the digital light processing method was used to manufacture the Zirconia part. Its mechanical property was evaluated via a three-point bending test with digital image correlation and fractography analysis. The 3D-printed Zirconia sample had a relative density of approximately 98.8% and a Vickers hardness value of 1128 HV. The flexural strength under parallel and vertical bending loads (with respect to the printing direction) were 56.63±3.97MPa and 70.98±6.62MPa, respectively. Surrounding by a few dense layers, the interior of the sintered sample was interlaced with needle-like and winding cracks. Under the three-point bending, the cracks initiated at the bottom surface due to the tension effect and propagated faster along the width direction than the thickness direction. There was a large area of cleavage morphology in the dense boundary layers, whereas the plastic fracture mode also appeared in the interior of the sintered samples. The digital light processing method is expected to be comparable to other advanced ceramic processing techniques for fabricating spatial lattice structural products.