Abstract
Excimer surface treatment was conducted on 7075-T651 aluminium alloy with the aim of improving the alloy's resistance to stress corrosion cracking (SCC) when tested in a NaCl solution. Using a pulse energy of 8 J/cm2, a laser-melted layer of about 8 μm thick was formed. Within the re-solidified laser-melted layer, the original grain boundaries of the wrought structure and most of the coarse constituent particles were removed. The grain boundaries of the re-solidified structure were found to be free from precipitates. The results of the SCC tests showed that after the 30-day immersion test, the untreated specimen was severely attacked with intergranular cracks that reached deep into the specimen; by contrast, no intergranular cracks were found in the laser-treated specimen. The form of corrosion attack in the laser-treated specimen took the form of corrosion pits instead. The electrochemical impedance measurements taken during the SCC test showed that the film resistance of the laser-treated specimen was always higher than that of the untreated specimen.
Original language | English |
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Pages (from-to) | 630-635 |
Number of pages | 6 |
Journal | Materials Letters |
Volume | 58 |
Issue number | 5 |
DOIs | |
Publication status | Published - 1 Feb 2004 |
Keywords
- Aluminium alloy
- Excimer laser
- Stress corrosion
- Surface treatment
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering