The effect of laser surface treatment on stress corrosion cracking behaviour of 7075 aluminium alloy

Tai Man Yue, C. F. Dong, L. J. Yan, Hau Chung Man

Research output: Journal article publicationJournal articleAcademic researchpeer-review

36 Citations (Scopus)

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 languageEnglish
Pages (from-to)630-635
Number of pages6
JournalMaterials Letters
Volume58
Issue number5
DOIs
Publication statusPublished - 1 Feb 2004

Keywords

  • Aluminium alloy
  • Excimer laser
  • Stress corrosion
  • Surface treatment

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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