Enriched alloy layer on an Al-Cu alloy studied by cyclic voltammetry

[摘要] The behaviour of enriched Al-0.7at.%Cu alloy is investigated using cyclic voltammetry. Enriched alloy layers at the interface between the alloy/oxide film were developed by alkaline etching at 5mAcm-2in 0.1M sodium hydroxide solution at 298K, with the time of etching determining the extent of enrichment. Cyclic voltammograms were recorded at a scan rate of 10mV s-1in naturally aerated 0.1M ammonium pentaborate solution at 298K. The current overshoot of the enriched alloys was different from that for non-enriched alloy. The latter material revealed the usual single peaks, which are very similar. In contrast, the overshoot comprised two or more components for the enriched alloys. The behaviour is suggested to be associated with the atomic bonding of aluminium in copper-rich and aluminium-rich regions of the enriched alloy layer, with influence on the activation potentials for oxidation of aluminium.

[发布机构] Universidad Industrial de Santander, Bucaramanga, Colombia^1;Instituto Colombiano Del Petróleo, Piedecuesta, Colombia^2;University of Manchester, Manchester, United Kingdom^3

[效力级别] 化学

[关键词] Activation potential;Al-Cu alloys;Alkaline etching;Ammonium pentaborate;Atomic bonding;Current overshoot;Cyclic voltammograms;Sodium hydroxide solutions