Author(s): Cristina De La Vieja Medina
Mentor(s): Divya Singh, Russell Reid
Institution UTech
3D printed plastics have gained immense popularity in the recent times given the direct integration with CAD based software platform as well as ease of manufacturing. In addition. However, the mechanical behavior of these plastics is not well defined. There are many factors that affect the integrity of 3D printed plastic – extrusion temperature, infill pattern and infill percentage being a few of them. So far, we have attempted to study the effect of these factors on the tensile and flexure (bending) and fracture strength of 3D printed plastics. Tensile and bending samples are prepared by varying one or more of the following – extrusion temperature, infill pattern and infill percentage. Further, the specimens are tested in a destructive manner for tensile and flexure strength following the standard tensile and three-point bending technique on a Pasco Materials Testing System. For understanding fracture strength as well as fracture mechanism of 3D printed plastics, single edge notched bend fracture samples are prepared by varying one or more of the following – extrusion temperature, infill pattern and infill percentage. These specimens are tested in a destructive manner under three-point bending technique on a Materials Testing System. Sample preparation as well as testing is carried according to ASTM D045-14 standards. The findings show that variations in print parameters significantly impact strength, emphasizing the need to standardize these parameters to boost strength and reduce costs. Similarly, the impact of print parameters on fracture strength highlights the importance of standardization for achieving maximum strength and cost efficiency. Going forward, we are interested in understanding and quantifying the phenomena physically and mathematically based on the results so far. These would require more experiments as well as simulation-based studies. We will also extend the study to understand the fatigue and hardness properties of these 3D printed plastics. The second scope of the study is to quantify the effect of environmental factors on the degradation of their mechanical strength. Such a study would provide a great insight on the life these 3D printed plastics under various operational conditions. The study also aims to capture the microscopic characteristics which literally govern the mechanical strength at the macroscopic level. Such an insight would potentially provide a guideline on how improve the material strength by tweaking the microscopic behavior itself.