Improvement of mechanical properties and corrosion resistance of SLM-AlSi10Mg alloy by an eco-friendly electric pulse treatment

In this study, we aim to effectively improve the mechanical properties and corrosion resistance of SLM-AlSi10Mg ally by electric pulse treatment (EPT), which is an eco-friendly method. The results show that EPT can reduce the micropores and dislocation density in SLM-AlSi10Mg alloy. It makes the dislocation distribution more uniform, without causing obvious effects on the phase composition, grain morphology and size. Compared with the asprinted SLM-AlSi10Mg alloy samples, the elongation the EPTed specimen is increased by 23.9%, while the ultimate tensile strength is only slightly decreased (about 1.2%). The fatigue test results of ten as-printed and EPTed samples selected randomly reveal that the maximum fatigue life of the EPTed sample is not significantly improved, but the minimum fatigue life is improved by about 164.4%, the average fatigue life is improved by about 49.4%, and the standard deviation is reduced by about 34.8%, which means that the EPT reduces the dispersion of fatigue life and improves the service stability. Moreover, electrochemical measurements confirme that the EPTed sample has more positive open circuit potential, corrosion potential, and pitting potential, and smaller corrosion current than those of the as-printed sample, which indicates that EPT enhances the corrosion resistance of SLM-AlSi10Mg alloy. In this paper, the service performance of AlSi10Mg alloys prepared by a clean process (SLM) is improved via an eco-friendly post-treatment process (EPT), which provides a new light to about cleaner production of metal parts.