Influence of Various Heat Treatment on Corrosion Resistance of As-Extruded Mg-9Li-3Al-2.5Sr Alloys

Abstract:

The corrosion behavior of Mg-9Li-3Al-2.5Sr alloy, solution treated at 400°C for 3h with various aging temperature (T_a; T_a=75,100,125,150,175°C), was investigated in 3.5% NaCl solution by immersion test and polarization curve measurement. Experimental results suggest that the alloy aged at150°Cfor 6h exhibits the highest corrosion resistance while the alloy treated at 75°C for 6h presents lowermost corrosion resistance. The corrosion resistance of the alloy is related to the grain size and the distribution of Al₄Sr compound. The segregation of intermetallic compounds can accelerate the corrosion process. It was found that duo to the proper solid-solution and aging treatment, intermetallic compounds were distributed evenly along the grain boundaries, which can reduce the corrosion rate and corrosion current. In addition,with the growth of grain, the decrease of the grain boundary area per unit volume lead to improvement of corrosion resistance of the alloys.

• Periodical: Materials Science Forum (Volume 788)
• Pages: 41-44
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.788.41
• Online since: April 2014
• Authors: Yuan Qing Yu*, Xiao Dong Peng, Hong Yu Yi, Jun Wei Liu
• Keywords: Corrosion Resistance, Mg-Li Alloys, Polarization Curve, Solution Treatment

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