Surface and Electrochemical Characteristics of Novel Chromate-Free Mn-V Oxyanion Sealed Tartaric–Sulfuric Acid Anodized Coating

Yoganandan, G and Balaraju, JN and Manikandanath, NT and Ezilselvi, V and Srivastava, Meenu and Naga Charan, KV and Anilchandra, AR and Manjunatha, CM (2018) Surface and Electrochemical Characteristics of Novel Chromate-Free Mn-V Oxyanion Sealed Tartaric–Sulfuric Acid Anodized Coating. Journal of Materials Engineering and Performance, 27. pp. 6175-6188.

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Abstract

In the present investigation, a novel chromate-free Mn and V oxyanions sealed tartaric–sulfuric acid anodic oxide coating (TSA) was developed on airframe grade aluminum alloy (AA2024). The results obtained from field emission scanning electron microscopy and energy-dispersive x-ray analysis showed effective surface modification of TSA after Mn-V oxyanions sealing (TSAMnVO). Potentiodynamic polarization results showed no significant difference in corrosion current density value (0.01 µA/cm2) after 1 h and 336 h of immersion in 3.5% NaCl solution. EIS result exhibited barrier layer resistance (Rb) value of TSAMnVO > 106 kΩ cm2 even after 336 h of immersion in NaCl solution. The 3D profile and Raman analysis showed no significant difference in the topography and composition, respectively, on the surface of TSAMnVO even after 1000 h of salt spray test. TSAMnVO also showed excellent adhesion with aircraft grade epoxy primer as per the ASTM 3359. Tensile and constant amplitude fatigue test results of TSAMnVO exhibited ultimate tensile strength and number of cycles to failure comparable with chromic acid anodization (CAA) process. Hence, the developed novel TSAMnVO coating system eliminates the usage of chromate ions completely in anodization process since it provides comparable corrosion resistance and mechanical properties with CAA.

Item Type:	Article
Uncontrolled Keywords:	aerospace aluminum alloy, electrochemical analysis, Mn-V oxyanion sealing, surface morphology, tartaric– sulfuric acid anodization
Subjects:	CHEMISTRY AND MATERIALS > Composite Materials CHEMISTRY AND MATERIALS > Nonmetallic Materials
Depositing User:	Mrs SK Pratibha
Date Deposited:	25 Aug 2022 12:05
Last Modified:	25 Aug 2022 12:05
URI:	http://nal-ir.nal.res.in/id/eprint/13637

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