J Mater Sci Technol ›› 2009, Vol. 25 ›› Issue (04): 508-512.

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Mechanical and Abrasive Wear Properties of Anodic Oxide Layers Formed on Aluminium

W. Bensalah1)†, K. Elleuch1) , M. Feki1), M. Wery2), H.F. Ayedi1)   

  1. 1) Unité de Recherche de Chimie Industrielle et Materiaux (URCIM), Departement of Materials Engineering, National School of Engineering, ENIS. B.P.W. 1173-3038 Sfax, Tunisia
    2) IUT Orsay- Paris XI University, Plateau du Moulon, 91400 ORSAY, France
  • Received:2008-08-21 Revised:2008-11-07 Online:2009-07-28 Published:2009-10-10
  • Contact: W. Bensalah

Abstract:

Aluminium oxide coatings were formed on aluminium substrates in oxalic acid-sulphuric acid bath. Abrasion tests of the obtained anodic layers were carried out on a pin-on-disc machine in accordance with the ISO/DP 825 specifications. The Vickers microhardness, D (HV0:2), and the abrasion weight loss, Wa (mg) were measured. Influence of oxalic acid concentration (Cox), bath temperature (T) and anodic current density (J) on D and Wa has been examined, and the sulphuric acid concentration (Csul) was maintained at 160 g?L-1. It was found that high microhardness and abrasive wear resistance of oxide layers were produced under low temperatures and high current densities with the addition of oxalic acid. The morphology and the composition of the anodic oxide layer were examined by scanning electron microscopy (SEM), atomic force microscopy (AFM), optical microscopy and glow-discharge optical emission spectroscopy (GDOES). It was found that the chemistry of the anodizing electrolyte, temperature, and current density are the controlling factors of the mechanical properties of the anodic oxide layer.

Key words: Aluminium oxide, Vickers microhardness, Abrasive wear