Establishment of Select Printing Parameters for Low-Cost Fused Deposition Modeling Printed Cast Iron Through Experimental Optimization

The fused deposition modeling (FDM) form of additive manufacturing provides a low-cost opportunity to quickly create unique parts with complex geometries using a high degree of precision. This is accomplished through a layer-by-layer extrusion of a metallic infused thermoplastic from a heated nozzle onto a build plate, until the 3D part is achieved. The ability to produce cheaply manufactured FDM printed cast iron parts would allow industries to bypass casting lead times and create custom cast iron parts without a machined mold. However, there has been minimal research into FDM printing of cast iron and the corresponding effects of printing parameters. The current study aims to determine the acceptable printing parameter ranges for FDM printed cast iron. The effects of three printing parameters (flow rate, infill density, and layer height) were studied with regard to the porosity, shrinkage, mass, and volume of the FDM printed cast iron. A flow rate range of 145–185% was determined to provide good-quality print while an infill density in the range of 100–125% for most flow rates provided acceptable print quality. Furthermore, the layer height was determined to have no significant effect on the printed part. Regarding the effect of printing parameters on the shrinkage, mass, and volume of the FDM printed part, the study showed that increasing the flow rate and infill density resulted in reduced shrinkage and a higher relative sintered mass and volume. Additionally, increasing the layer height showed an insignificant change in the sintered mass, volume, and shrinkage. Sintered samples obtained densities ranging between 5.02 and 5.44 g/cc and porosity measurements from 7.14% to 18.85%. This is one of the first studies on the FDM printing of cast iron. The results would enable researchers and hobbyists to successfully print their first cast iron part.