Effect of Testing Standard on Parameter Optimization of Fused Deposition Modelling Process

Fused deposition modeling (FDM) has emerged and spread worldwide as the most commonly used additive manufacturing (AM) technique. However, to this day, there has been no specific available guidance to evaluate the mechanical performance of FDM products quantitatively. The current approach to mechanical testing standards utilizes existing guidelines for testing materials, which may lead to a discrepancy in results. The topic of this article is to investigate three widely applied testing standards, namely ASTM, ISO, and GB, to analyze the impact of which on the tensile strength of FDM samples and in what amount. Polylactide (PLA) samples are prepared according to the three standards above. Four parameters (nozzle temperature, print speed, layer thickness, and raster width) with three levels are selected as control variables, and the Taguchi method is used for parametric optimization. Statistical analysis shows that the importance orders of parameters that affect the tensile performance as well as optimal levels for maximizing tension obtained based on different criteria are different. In addition, the results from ISO and GB samples are consistent, which are quite different from that of ASTM samples. The outcome of this study is helpful for the selection of testing standards in the FDM process and can make a reference for the experimental design for FDM users.