Ultrasonic Welding of Similar/Dissimilar MEX-3D Printed Parts Considering Energy Director Shape, Infill, Welding Time and Amplitude

Additive manufacturing (AM), a key technology in the evolution of Industry 4.0, has revolutionized production processes by enabling the precise, layer-by-layer fabrication of complex and customized components, enhancing efficiency and flexibility in smart manufacturing systems. However, one significant challenge hindering the acceptance of this technology is the limited print size, constrained by the machine’s small bed. To address this issue, a suitable polymer joining technique could be applied as a post-fabrication step. The present article examines findings on the Ultrasonic Welding (UW) of Material Extrusion (MEX)-3D printed parts made from commonly used thermoplastics, Acrylonitrile Butadiene Styrene (ABS) and Polylactic Acid (PLA). Key parameters in the process are identified and optimized through statistical methods, such as Design of Experiments (DOE), Taguchi, and Analysis of Variance (ANOVA). The findings showed that the material combination and the design of the energy directors had the greatest impact on the joint strength and elongation, leading to a joint efficiency increase of up to 174.52%. The research’s feasibility was additionally supported by applying the results to weld and fabricate a car’s rear wing and an agricultural drone, both of which demonstrated strong structural integrity. The proposed method is anticipated to increase acceptance of joining and welding techniques in the future, with UW showing significant potential for effectively joining 3D-printed parts and addressing the bed size limitations of 3D printers.