Journal of the Korean institute of surface engineering (한국표면공학회지)

The Korean Institute of Surface Engineering (한국표면공학회)
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Surface Hardness Measurement of Anodic Oxide Films on AA2024 based an Ink-Impregnation Method

  • Moon, Sungmo (Surface Technology Division, Korea Institute of Materials Science) ;
  • Rha, Jong-joo (Surface Technology Division, Korea Institute of Materials Science)
  • Received : 2020.04.16
  • Accepted : 2020.04.28
  • Published : 2020.04.30
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Abstract

This paper is concerned with type of imperfections present within the anodic oxide films on AA2024 and surface hardness of the anodic film measured after ink-impregnation. The anodic oxide films were formed for 25 min at 40 mA/㎠ and 15±0.5℃ and 300 rpm of magnet stirring rate in 20% sulfuric acid solution. The ink-impregnation allows clear observations of not only the imperfections within the anodic oxide films but also an indentation mark on the oxide film surface made by a pyramidal-diamond penetrator for the hardness measurement. There were observed four different regions in the anodic oxide films on AA2024 and the surface hardness of the anodic oxide films appeared to be crucially dependent on the type of defects, showing 60~100 Hv on the oxide surface region I with large size black defect, 100~140 Hv on the oxide surface region II with large size grey defect, 140~170 Hv on the oxide surface region III with mall size black and/or grey defects and 170~190 Hv on the oxide surface region IV without defects. The pyramidal indentation marks were observed to be distorted in the regions with a large size black and grey defects, while no distortion of the indentation mark was observed in the regions with small size defects and without visible defects.

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References

  1. Sanghyuck Moon, Sungmo Moon and Sugun Lim, Formation Characteristics of Hard Anodizing Films on 6xxx Aluminum Alloys, J. Kor. Inst. Surf. Eng. 52 (2019) 203-210.
  2. Sungmo Moon, Anodic Oxidation Treatment Methods of Metals, J. Kor. Inst. Surf. Eng. 51 (2018) 1-10. https://doi.org/10.5695/JKISE.2018.51.1.1
  3. Sungmo Moon, Kihun Jeong, Sugun Lim. Formation Behavior of Anodic Oxide Films on Al 6061 Alloy in Sulfuric Acid Solution, J. Kor. Inst. Surf. Eng. 51 (2018) 393-399. https://doi.org/10.5695/JKISE.2018.51.6.393
  4. Sungmo Moon, Cheolnam Yang and Sangjo Na, Formation Behavior of Anodic Oxide Films on Al7075 Alloy in Sulfuric Acid Solution, J. Kor. Inst. Surf. Eng. 47 (2014) 155-161. https://doi.org/10.5695/JKISE.2014.47.4.155
  5. S. Moon, Y. Nam, Anodic oxidation of Mg-Sn alloys in alkaline solutions, Corrosion Science 65 (2012) 494-501. https://doi.org/10.1016/j.corsci.2012.08.050
  6. Fan Zhang, Cem Ornek, Jan-Olov Nilsson, Jinshan Pan, Anodisation of aluminium alloy AA7075 - Influence of intermetallic particles on anodic oxide growth, Corrosion Science 164 (2020) 108319-108322. https://doi.org/10.1016/j.corsci.2019.108319
  7. Massimiliano Bononi, Roberto Giovanardi, Andrea Bozza, Paolo Mattioli, Pulsed current effect on hard anodizing process of 2024-T3 aluminium alloy, Surface and Coatings Technology 289 (2016) 110-117. https://doi.org/10.1016/j.surfcoat.2016.01.056
  8. Jieqin Lu, Guoying Wei, Yundan Yu, Changfa Guo, Li Jiang, Aluminum alloy AA2024 anodized from the mixed acid system with enhanced mechanical properties, Surfaces and Interfaces 13 (2018) 46-50. https://doi.org/10.1016/j.surfin.2018.08.003
  9. T. Aerts, Th. Dimogerontakis, I. De Graeve, J. Fransaer, H. Terryn, Influence of the anodizing temperature on the porosity and the mechanical properties of the porous anodic oxide film, Surface & Coatings Technology 201 (2007) 7310-7317. https://doi.org/10.1016/j.surfcoat.2007.01.044
  10. Moonsu Kim, Hyeonseok Yoo, Jinsub Choi, Nonnickel-based sealing of anodic porous aluminum oxide in $NaAlO_2$, Surface & Coatings Technology 310 (2017) 106-112. https://doi.org/10.1016/j.surfcoat.2016.11.100
  11. Tatsuya Kikuchi, Akimasa Takenaga, Shungo Natsui, Ryosuke O. Suzuki, Advanced hard anodic alumina coatings via etidronic acid anodizing, Surface and Coatings Technology 326 (2017) 72-78. https://doi.org/10.1016/j.surfcoat.2017.07.043
  12. Sungmo Moon, Novel Methods for Measuring the Surface Hardness of Anodic Oxide Films on Aluminum Alloy, J. Kor. Inst. Surf. Eng. 53 (2020) 36-42. https://doi.org/10.5695/JKISE.2020.53.1.36
  13. T. Vuherer, L. Milovic, V. Glih, Behaviour of small cracks during their propagation from Vickers indentations in coarse-grain steel: An experimental investigation, International Journal of Fatigue 33 (2011) 1505-1513. https://doi.org/10.1016/j.ijfatigue.2011.06.008
  14. P. Ramana Reddy, K. M. Ajith, N. K. Udayashankar, Micro and nano indentation analysis of porous anodic alumina prepared in oxalic and sulphuric acid, Ceramics International 42 (2016) 17806-17813. https://doi.org/10.1016/j.ceramint.2016.08.109