Fused deposition modelling (FDM) process parameter optimization to minimize residual stresses of 3 d printed carbon fiber nylon 12 hip joint implant

Abstract

AbstractResidual stresses induced during the layer‐by‐layer fabrication process affect mechanical properties and dimensional accuracy of additively manufactured components. Some of these effects cannot be corrected by post processing like heat treatment. This work aims at optimizing fused deposition modelling process parameters for the least residual stresses during 3D printing of carbon fiber reinforced nylon 12 hip implant. Taguchi design of experiment was used to study the effect of printing temperature, layer thickness and print speed on the residual stresses using the Digimat‐ additive manufacturing software. The results show that the optimal factor setting levels for minimizing part residual stresses were printing temperature of 255 °C, layer thickness of 0.3 mm, and a print speed of 50 mm/s. Printing temperature has the most significant influence on the residual stresses. The combination of the optimum parameter levels yielded the least simulation residual stresses of (41.75 6.53) MPa while the experimental residual stress results were (40.7 7.7) MPa. The simulated and experimental results agreed with minimal percentage difference of (2.51 0.04) %. Tensile and compressive properties of 3D printed carbon fiber nylon 12 composite hip implant matched those of cortical bone. The fracture surface of failed tensile specimens revealed that failure occurred through fiber pull‐out and matrix fracture