Material extrusion 3D printing of ceramic structures with overhangs: rheological aspect and introduction of powder-on-demand supporter

Abstract

Additive manufacturing (AM), represented as a manufacturing process, which is easily applicable to intricate designs, is widely considered in a variety of industries as a simple and cost-effective solution that complements or replaces traditional manufacturing processes. However, due to the demanding properties of ink materials employing ceramic materials, more stringent considerations are required in selecting an appropriate printing technique and implementing the rheological properties of the ceramic ink suitable for the selected printing technique. Here, material extrusion (ME) was selected as a 3D technique applicable to ceramic materials, and the rheological requirements of ceramic pastes that maximize their printability in ME were scrutinized in detail. It was found that the viscoelastic properties of the ceramic pastes played an important role in determining the flowability, cumulative height, and overhang angles that can be allowed in ME. A new supporter system for overhangs, powder-on-demand supporter (PODS), was introduced to ME and demonstrated to understand if PODS can further extend the limits in cumulative height and overhang angles allowed in ME.