Tribological performance of the novel 3D printed PLA/Almond shell particles added PLA Single Gradient Functionally Graded Material (SGFGM)

The present study aims to develop a novel SGFGM (Single Gradient Functionally Graded Material) PLA/AlmPLA (Almond shell particles added PLA) for wear-resistant applications using 3D printing technology. The novel Almond PLA and neat PLA filaments are extruded using filament extrusion technique, the extruded filaments are used for the current study. Cylindrical-shaped sliding wear test samples are 3D printed with a 50:50 ratio of PLA and AlmPLA polymers. The tribological study is conducted to analyze the dry sliding wear resistance and frictional coefficient of the 3D printed PLA/AlmPLA samples. The samples are prepared by changing the levels of the print-factors such as Infill Density (ID), Printing Speed (PS), Layer Height (LH), and Printing Temperature (PT). The L₁₆ Taguchi orthogonal array is developed to lessen the experimental runs and find the optimal condition for the lowest specific wear rate and co-efficient of friction of the respective PLA/AlmPLA SGFGM. The result depicts that the lowest wear and friction is observed at a LH of 0.15 mm, a PT of 210℃, a PS of 20 mm/sec, and an ID of 100 %. In the context of wear, the print-factors like PS and LH resulted in higher contribution like 28.92 % and 24.86 % while for friction, the print-factors like PT and ID developed higher influences of 31.79 % and 25.35 %. Surface features of the 3D printed samples show that the highest ID and lowest LH observe better dimensional stability at the interface, this may enhance the interfacial adhesion of the developed PLA/AlmPLA SGFGM. Overall, the developed PLA/AlmPLA SGFGM composites will be very suitable for heavy-duty industrial automobile interiors, automotive flooring trays, and bins in food packaging.