Issue 92, 2015

Tailored products of dealloying as-sintered Al–Cu alloys in sodium hydroxide solutions

Abstract

In this work, a two-step method of cold-press sintering–dealloying was applied to fabricate nanostructured copper/copper oxide mixtures. As-sintered AlxCu(100−x) (x = 60, 67 and 85 at%) alloy bulks that were prepared using cold-press sintering were dealloyed in 20 wt% NaOH solution under free corrosion conditions. In addition, Al67Cu33 was studied in detail to study the effects of sintering parameters on precursors and products. The XRD and SEM results suggest that a higher temperature and long duration are beneficial to promote atom diffusion and the formation of a single Al2Cu phase and tailored Cu, Cu2O and CuO with various morphologies were obtained after dealloying. During dealloying, the Al2Cu phase could be fully corroded, whereas the AlCu phase obtained from a higher sintering temperature remains after dealloying. Electrochemical studies show that the critical corrosion potential (Ecrit) of the as-sintered alloys, pure Al and pure Cu, are extremely close to the free corrosion potential (Ecorr), the intersection point of potentiodynamic cathodic and anodic polarization curves. Cyclic voltammetry results imply that the formation of oxides may be related to the reaction of dissolved oxygen and copper ions. A group of recommended parameters was identified: a pressure of 312.5 MPa, sintering temperature of 500 °C and holding time of 60 min, from which a mixture of Cu/Cu2O/CuO could be obtained which exhibits an excellent initial (10 min) degradation efficiency of 77.4% to methyl orange when exposed in an ultrasonic environment in ambient atmosphere.

Graphical abstract: Tailored products of dealloying as-sintered Al–Cu alloys in sodium hydroxide solutions

Supplementary files

Article information

Article type
Paper
Submitted
23 Jun 2015
Accepted
24 Aug 2015
First published
04 Sep 2015

RSC Adv., 2015,5, 75044-75054

Tailored products of dealloying as-sintered Al–Cu alloys in sodium hydroxide solutions

J. Li, Z. Yang, T. Wang, N. Yu, L. Sun, C. Nie, H. Teng, C. Jin, X. Chen and H. Geng, RSC Adv., 2015, 5, 75044 DOI: 10.1039/C5RA12112D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements