Nondestructive analysis of corrosion in ageing hardened AA6351 aluminium alloys.

Aluminum alloys have been chosen over other lightweight structural materials because of their advantages regarding strength, long-term durability, and low cost. Aluminum comes under the category of highly reactive metals, where an inherently stable oxide layer can protect against aggressive corrosive conditions. Therefore, this research investigated the application of the ultrasonic nondestructive technique for inspection and monitoring of corrosion behavior of AA6351 heat-treated aluminum alloys. The samples were artificial age hardened at five different conditions. The complementary engineering experiments for materials evaluation included hardness, X-ray diffraction and salt spray tests. Overall findings showed correlations between ultrasonic and destructive data representing a fast, versatile and reliable inspection technique. Furthermore, findings show a significant correlation (>99%), thus supporting the benefits of the multiparametric ultrasonic test for heat treatment inspection and quality control of lightweight structural materials. • The effect of age hardening on the mechanical and corrosion behavior of AA6351 alloys was examined. • Findings support the applicability of the ultrasonic nondestructive tests for corrosion evaluation. • The technique tested enables the determination of peaks and adjacencies of mechanical strength in AA6351 alloys. • The technique tested can be used in Al-alloys in T4 and T6 conditions. [ABSTRACT FROM AUTHOR]