Comparison of two-step surface treatment on surface roughness and corrosion resistance of TC4 alloy parts prepared by SLM and SEBM

To reduce the surface defects of additive manufacturing forming parts and improve surface quality such as surface roughness and corrosion resistance, a two-step surface treatment technology, namely, pre -polishing combined with micro-arc oxidation (MAO), is employed to treat bulk samples constructed by selective laser melting (SLM) and selective electron beam melting (SEBM), respectively. Effects of surface morphology and coating thickness on surface roughness and corrosion resistance are systematically studied. Results show that the two-step surface treatment weakens the step effect of the original sample surface distinctively. Meanwhile, the MAO coating can improve the corrosion resistance of the original sample significantly. The corrosion current density Icorr of SLM specimen-is reduced from 6.212 x 10-5 A/ cm(2) to 2.493 x 10(-7) A/cm(2) (t = 15 min), and the Icorr of SEBM specimen-is reduced from 8.013 x 10-6 A/cm(2) to 2.562 x 10-6 A/cm(2) (t = 15 min). (c) 2022 Published by Elsevier B.V.

Automated summary

This study employs a two-step surface treatment technology to improve the surface defects and quality of parts fabricated by selective laser melting (SLM) and selective electron beam melting (SEBM). The results show that the two-step surface treatment effectively reduces the step effect of the original samples and enhances the corrosion resistance through micro-arc oxidation (MAO) coating.