Investigations on the effect of Spin Friction Welding parameters on joint strength and cylindricity of similar/dissimilar Material Extrusion (MEX) 3D printed parts

Material Extrusion (MEX) 3D printing is revolutionizing manufacturing by transforming digital designs into tangible innovations by its layer-by-layer approach. However, an important issue impeding the adoption of this technology is the limited size of the prints due to the machine's small bed. An appropriate polymer joining technique can be used as a post-fabrication step to circumvent this issue. This paper explores the findings related to the joining of MEX-3D printed parts fabricated from generally preferred thermoplastics, Acrylonitrile Butadiene Styrene (ABS), and Polylactic acid (PLA) by the Spin Friction Welding (SFW) technique. The critical parameters involved in the process are identified and optimized using statistical tools including Design of Experiments (DOE), Taguchi, and Analysis of Variance (ANOVA). The results revealed that the type of material combination as well as the number of perimeter shells had the highest effect on the joint strength and cylindricity of the welds, resulting in the joint efficiency going up to 93.16 %. The practicability of the research was further approved by implementing the results to weld the sections of a service saddle point of a pipeline, wherein the weld displayed good strength and integrity. With the suggested method, it is expected that in the future, joining and welding procedures will gain more acceptance with SFW in particular showing great promise for joining cylindrical and rotary MEX-3D printed parts.