Interlayer bonding improvement of material extrusion parts with polyphenylene sulfide using the Taguchi method

Abstract

Material extrusion additive manufacturing (MEAM) and other additive manufacturing methods provide part design options that would be difficult or impossible to realize with conventional manufacturing methods. However, the mechanical properties of parts produced with MEAM are lower than bulk material properties because of the interfaces between roads and layers inherent to the additive build technique of MEAM. In addition, the success of the MEAM process and the resulting part quality depend on the proper selection of the many settings and variables present in MEAM. The effects of material dependent MEAM process parameters on the interlayer bonding and percent crystallinity of MEAM parts fabricated with polyphenylene sulfide (PPS) were examined in this study using a design of experiments technique known as the Taguchi method. The MEAM parameters studied were print temperature, heat-treatment time, and heat-treatment temperature. MEAM parts were tested perpendicular to the layers in order to characterize the interlayer bonding. Heat-treatment temperature was shown to be the most influential parameter on all the studied properties. Utilizing heat-treatments on MEAM parts increased the ultimate tensile strength (UTS) from 52% of the PPS film UTS to 80%. Similar increases were seen in the Young’s modulus, from 57% of the PPS film Young’s modulus to 72%. The study showed that utilizing post-processing heat-treatments on MEAM parts could improve the interlayer bonding in these parts. The use of these heat-treatments could be applied to other materials in order to increase the use of MEAM parts in end use applications.