Surface Hardness Measurement of Anodic Oxide Films on AA2024 based an Ink-Impregnation Method

• Published in: Biuletyn Uniejowski Vol. 53; no. 2; pp. 80 - 86
• Main Authors: Sungmo Moon, Jong-joo Rha
• Format: Journal Article
• Language: English
• Published: 한국표면공학회 01.04.2020
• Subjects: 기계공학; Surface hardness; ink-impregnation method; anodic oxide film; AA2024
• ISSN: 1225-8024; 2299-8403; 2288-8403

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/cm2 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. KCI Citation Count: 1