A review on metallic and ceramic material extrusion method: Materials, rheology, and printing parameters

Ink-based printing or direct ink writing (DIW) falls under the material extrusion as defined in ASTM52900. This method deposits ink-based material layer by layer to form a 3D article; combining it with metallurgy processing allows this printing method to 3D print metal and ceramic materials. This simple process presents significant advantages compared to the other additive manufacturing method. However, it also presents new challenges to handling ink-based material. This review intended to cover the latest progress related to metallic and ceramic materials through the direct ink writing method, including printability based on (1) ink blends and properties and (2) parametric analysis, which includes printing mechanics. Ink printability is the key to DIW success in which the ink flow is crucial during the extrusion process while being able to maintain the extruded shape and structure. Different ink compositions possess different rheological properties that can determine the printability of a specific ink composition. Printing parameters also play an essential role during the printing process, especially during optimisation. The current progress of DIW is also assessed to identify specific challenges and further development, which can be helpful to pave the way for improved printed products in terms of visual quality, strength and functionality.