Improving Mechanical and Corrosion Properties of 6061 Al Alloys via Differential Speed Rolling and Plasma Electrolytic Oxidation

Materials (Basel). 2024 Mar 8;17(6):1252. doi: 10.3390/ma17061252.

Abstract

This study explores the combined potential of severe plastic deformation (SPD) via differential speed rolling (DSR) and plasma electrolytic oxidation (PEO) to enhance the material performance of 6061 Al alloys. To this end, DSR was carried out at a roll-speed-ratio of 1:4 to obtain ~75% total thickness reduction and a final microstructure of <1 µm. The rest of the samples were annealed to obtain various grain sizes of ~1, ~25, and ~55 μm. Through DSR, the hardness of the material increased from ~64 to ~102 HV. Different grain sizes altered the plasma behavior which further influence the growth of the coating layer, where the fine grain size produced a compact structure beneficial for corrosion protection. This synergy offers tailored materials ideal for high-performance applications across diverse industries, combining enhanced bulk properties from DSR with optimized surface attributes from PEO.

Keywords: Al alloys; anti-corrosive coating; corrosion; differential speed rolling; hardness; plasma electrolytic oxidation.

Grants and funding

This research was funded by the Industrial Innovation Talent Growth Project of the Korean Ministry of Trade, Industry and Energy funded by the Korea Institute for Advancement of Technology (#P0023676, Expert Program for Sustainable Metals Industry).