Effects of Quenching on the Corrosion Behaviour of Cast Al -2.5% Zn Alloy System

• Published in: Research journal of environmental sciences Vol. 1; no. 6; pp. 294 - 301
• Main Authors: Ekuma, CE, Idenyi, N E, Obini, O C, Onwu, F K, Neife, SI
• Format: Journal Article
• Language: English
• Published: 01.06.2007
• Subjects: Alloys; Corrosion; Diffusion; Metals; Oxygen; Q1; Zinc
• ISSN: 1819-3412
• DOI: 10.3923/rjes.2007.294.301

The corrosion characterization of quenched Al -2.5% Zn binary alloy system has been concluded using weight loss technique. Preweighed coupon samples were immersed in 0.25, 0.5 and 1.0M of simulated hydrochloric and tetraoxosulphate (vi) acidic environments, respectively. The set up were allowed to stand for 96 h with a set withdrawn 24 h for corrosion rate characterization. The result depicts that of passivating metal of an initial steep rise, followed by a gradual decrease in CPR, which was maintained in the entire environment and increased as the molar concentration of the media increased. The observed increase in severity of attack in all the test coupons subjected to HCl environment may be ascribed to increased ionization of the higher oxygen rich media, a consequence of higher diffusion rate that lead to increased conductivity causing redistribution in the grain boundary structure of the alloy predicated on the presence of zinc which lead to the formation of eutectic phase, that consequently caused mismatch of Al-Zn binary alloy system.