An experimental investigation of selective laser melting parameters effects on ferromagnetic properties of pure iron in both the as-built and annealed conditions

Abstract

In this study, the effect of selective laser melting (SLM) parameters on the magnetic properties of pure iron has been experimentally extracted both in the as-built (A-Built) and stress-relieved (H-Treat) conditions, and the optimum levels of the parameters have been determined for optimum magnetic properties. The SLM process parameters include laser power, scanning speed, and hatch spacing, and the design of experiments was done by the Taguchi method. After manufacturing and preparing the specimens, their hysteresis curves were measured using vibrating-sample magnetometer (VSM), and the magnetic properties of the SLMed pure iron were calculated. Signal-to-noise analysis was used to determine the optimal levels of parameters for achieving the best magnetic properties. For samples’ permeability and coercivity, the best possible regression equations were extracted, and SOBOL sensitivity analysis was used to determine the most contributing input variable to the outputs. The results indicate that the laser power parameter has the most significant impact on the magnetic properties of the produced parts. Two of samples were annealed at 820 °C for 1 h, and then magnetic properties were remeasured. Although there was not a significant change in permeability, and magnetization saturation of the samples, coercive force has decreased approximately 60 %. This reduction in annealing is desirable for some AC electrical devices.