Integrating additive and subtractive manufacturing to optimize surface quality of MEX parts

• Hybrid manufacturing integrates MEX and turning to enhance surface roughness. • Surface roughness reduced from 24.382 µm (Ra) to 2.309 µm via optimized turning. • Taguchi OA method efficiently optimized machining parameters with minimal experiments. • Feed rate was the most factor, contributing over 80 % to surface roughness reduction. This research investigates the integration of additive and subtractive manufacturing to enhance the surface quality of parts produced using Material Extrusion (MEX) technology. While MEX is a widely adopted additive manufacturing technique, it often results in suboptimal surface finishes, necessitating further post-processing. In this study, turning was employed as a subtractive process to improve the surface quality of MEX-fabricated cylindrical parts. The Taguchi Orthogonal Array (OA) method was utilized to optimize turning parameters, including cutting speed, feed rate, and depth of cut, with the objective of minimizing surface roughness. The initial roughness values of the printed parts were measured at 24.382 µm for Ra and 104.973 µm for Rz. After the turning process, significant improvements were observed, with minimum values of 2.309 µm for Ra and 13.465 µm for Rz. Analysis of variance (ANOVA) indicated that feed rate was the most significant factor affecting surface roughness, contributing over 80 % to the overall reduction. The optimized turning parameters to achieve the required surface finish were a cutting speed of 83 m/min, a feed rate of 0.1 mm/rev, and a depth of cut of 0.5 mm. These findings underscore the effectiveness of combining additive and subtractive processes, providing a viable solution for achieving high-quality surface finishes in MEX-fabricated components. The integration of these two processes offers a robust approach to reducing surface roughness, enhancing part performance, and minimizing the need for extensive post-processing in industrial applications.