Near-defect-free manufacturing and enhanced wear and corrosion resistances of 316L stainless steel achieved by interlayer hybrid process with laser additive manufacturing, milling machining, and ultrasonic rolling
To eliminate the internal defects induced by additive manufacturing (AM) process and enhance the metal performances within the entire size, this study proposed an interlayer hybrid process with laser additive manufacturing, milling subtractive machining, and ultrasonic equivalent rolling. In this study, the interlayer additive/subtractive/equivalent hybrid process was used to improve the overall wear and corrosion resistances of additively manufactured 316L (AM316L). The results demonstrated that the interlayer hybrid process had the great potential to achieve the defect-free manufacturing of metals. The milling subtractive machining played a crucial role in eliminating the lack of fusion (LOF) defect, and the ultrasonic equivalent rolling had significant effects on closing pores, refining grain size, increasing dislocation density, improving hardness, and enlarging compressive residual stresses in overall AM316L. Benefitting from the near-defect-free manufacturing with the porosity value of 0.01 % and the interlayer strengthening, the wear and corrosion resistances of AM316L subjected to the interlayer hybrid process were improved with the wear rate and corrosion current density decreased by 8.15 % and 43.8 %, and the polarization resistance increased by 37.5 %, respectively.