Combination of High Strength and Corrosion Resistance in AA5052 Alloy Using Cryorolling and Micro Arc Oxidation

For enhancing the strength of AA 5052 alloy, cryorolling is performed up to 50% and 75% reduction. The 75% reduction cryorolling shows excellent strength than the unrolled and 50% reduction alloy. However. Cryorolling of AA5052 alloy results in poor corrosion resistance. The reduction in corrosion resistance is due to an increase in dislocation density by cryorolling. Hence micro-arc oxidation (MAO) is adapted to coat Al2O3 on the surface to reduce the corrosion rate of cryorolled sheets. MAO is performed with three borax concentration viz. 0, 1 and 2 g in the solution. The increase in borax concentration up to 1% shows high corrosion resistance and a further increase in borax concentration has shown detrimental influence on corrosion resistance which is due to the delamination of the coating with severe cracking. (C) 2020 Elsevier Ltd. All rights reserved.