Corrosion Properties and Morphology of Laser Melted Aluminum Alloy 8022 Surface


Yilbas B. S. , Khaled M., Karatas C.

JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE, cilt.18, sa.1, ss.1-7, 2009 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 18 Konu: 1
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1007/s11665-008-9258-9
  • Dergi Adı: JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
  • Sayfa Sayıları: ss.1-7

Özet

Laser surface melting of aluminum alloy 8022 is considered and electrochemical studies of the laser-melted and as-received alloy surface are carried out. The surface morphology and metallurgical changes in the laser-melted region are examined using optical microscopy, electron scanning microscopy (SEM), and atomic force microscopy (AFM). Elemental changes in the specimens after the laser-melting process are examined using energy dispersive spectroscopy (EDS), and x-ray diffraction (XRD) is used for assessment of the compound formed after the laser-treatment process. Nitrogen is used as an assisting gas during the laser-melting process to prevent high-temperature oxidation reactions. It is found that the laser-melted surfaces is free from cracks and deep cavities. The oxygen diffusion in the surface region of the melt layer forms Al(2)O(3) compound in the surface vicinity. The corrosion current increases significantly for the laser-melted specimens due to the irregular surface structure. AC impedance results showed a decrease in pores resistant and an increase in pores capacitance. In addition, the surface morphology resulting from the laser melting gives rise to pitting sites at the surface.