Effect of Printing Parameters on Dimensional Error and Surface Roughness Obtained in Direct Ink Writing (DIW) Processes

Abstract

Prostheses made from ceramic materials have the advantages of producing little debris and having good durability, compared with those made from metal and plastic. For example, hip prostheses require a porous external area that allows their fixation by means of osseointegration and a solid internal area that will be in contact with the femoral head. The manufacturing of complex ceramic shapes, by means of machining processes, for example, is complicated and can lead to breakage of the parts because of their fragility. The direct ink writing (DIW) process allows the printing of ceramic pastes into complex shapes that achieve their final strength after a heat treatment operation. This paper studies both the dimensional error and surface finish of porous zirconia prismatic parts prior to sintering. The variables considered are infill, layer height, printing speed, extrusion multiplier and bed temperature. The responses are the dimensional error of the lateral walls of the samples and an areal roughness parameter, the arithmetical mean height, Sa. Mathematical models are found for each response, and multiobjective optimization is carried out by means of the desirability function. The dimensional error depends mainly on the interaction between layer height and infill, while the roughness on the interaction between infill and printing speed. Thus, infill is an important factor for both responses. In the future, the behavior of compact printed parts will be addressed.

Effect of Printing Parameters on Dimensional Error, Surface Roughness and Porosity of FFF Printed Parts with Grid Structure

“…Its effect on surface finish and dimensional error has been scarcely studied in the literature about FFF processes. In a different extrusion printing process, direct ink writing (DIW) of ceramic inks, the flow rate or extrusion multiplier parameter had a low effect on surface roughness and dimensional error [ 39 ]. However, the flow rate required in FFF or in DIW processes could be quite different because of the different rheological behavior of both materials.…”

Analysis of AM Parameters on Surface Roughness Obtained in PLA Parts Printed with FFF Technology

“…Ideally, Rku should be close to 3, corresponding to a normal distribution of heights in the profile, and Rsk should be 0 in order to obtain a symmetrical profile. However, in extrusion 3D printing processes Rku values below 2 and slightly negative Rsk values have been reported [ 37 ], corresponding to highest valleys than peaks and a slightly rounded profile.…”

Use of FDM Technology in Healthcare Applications: Recent Advances

“…Direct Ink Writing (DIW) is another technology within the material extrusion category. It is based on pushing a paste, for example made of ceramic, through a nozzle, and later depositing it in order to manufacture 3D printed samples [4]. This is the main technology used in bioprinting [5].…”