Abstract Scope |
3D printing is different from traditional fabricating techniques such as casting and machining, and it can produce complex structures with tunable properties. The extrusion-based direct ink writing printing technique can print the final product with minimal or no waste but suffers poor mechanical strength due to the incorporation of voids during printing. This calls for improvements in mechanical properties to survive during load-bearing applications. Fiber reinforcement and its orientation, porosity, or void density directly affects the printed structures which can be controlled by varying input variables such as printing speed, nozzle diameter, the weight percentage of reinforcement, etc. Here, 15%(w/v) polyvinyl alcohol ink was prepared and then mixed with different weight percentages of Graphite as reinforcement to print samples through different nozzle diameters with variable flow rates to investigate its effect on the directionality of reinforcement, porosity, and mechanical properties. Rheological tests of inks were conducted to optimize and study the printability of prepared ink. Further tensile strength, density, porosity percentage, and fiber orientation angles were measured via a universal testing machine and transmission optical microscope. Rocky and ANSYS software packages visualized the whole process using discrete element modeling and computational fluid dynamics numerical methodology. Finally, the effects of controlled variables on the directionality and hence the mechanical properties were analyzed and process-property dependency was validated. These findings will open new opportunities and guidelines in further strengthening the mechanism of the composite produced via the 3D printing process. |