News: Indian Scientists have developed an environmental-friendly process, which can provide excellent corrosion resistance to the high-strength aluminium (Al) alloys extensively used in aerospace, textile, and automotive applications.
- It involves an electrochemical method for the production of an oxide film on the metallic substrate.
- High-strength aluminium (Al) alloys are extensively used in aerospace, textile, and automotive applications owing to their low density and high specific strength.
- Aerospace components made out of Al alloys include landing gear, wing spar, which is the main structural part of the wing, fuselage (main body of an aircraft), aircraft skins or outer surface and pressure cabins.
- These parts often need resistance against wear, corrosion damages, and enhanced fatigue life. The widely used technique for Al alloys to improve corrosion resistance called hard anodizing (HA) process is an electrolyte-based coating deposition. It involves sulphuric/oxalic based electrolytes, which emits not only toxic fumes but are also hazardous to handle during processing.
- In order to cater to the growing demand for cleaner industrial processes, an environmental-friendly process called micro-arc oxidation (MAO) has been developed.
- The process which involves an alkaline electrolyte is capable of providing better wear and corrosion resistance compared to the HA process. MAO is a high-voltage driven anodic-oxidation process, which through an electrochemical method, produces an oxide film on a metallic substrate.