A New Method for Evaluation of Pitting Corrosion Resistance of Mg Alloys

Abstract

As pitting corrosion proceeds hydrogen ions are consumed. The possibility of using the pH change as an indicator for the pitting corrosion resistance properties of Mg alloy was investigated. Mg alloys for testing were mounted in epoxy resin with an area of 0.5 mm 2 area exposed to the solution (5wt% NaCl). A small volume of solution, about 4 cm 3 , was used in order to intensify the pH change. All tests were conducted at room temp. (20°C). The effects of the solution pH and the changes in pH were investigated. The behaviour of pH change obtained from these tests showed that pitting corrosion proceeded through two steps: pitting initiation and pitting propagation. Similar results were obtained for all the alloys tested.Brought to you by | Purdue University Libraries Authenticated Download Date | 6/22/15 3:05 PM

Corrosion electrochemistry of magnesium (Mg) and its alloys

“…It has been generally accepted (Froats et al, 1987;Hur and Kim, 1998;Song, 2005bSong, , 2006, that dissolved oxygen does not play an important role and hydrogen evolution is the main cathodic process involved in the corrosion of magnesium. Therefore, hydrogen evolution always dominates the cathodic process in an aqueous environment.…”

Corrosion behavior of magnesium alloys and protection techniques

“…For example, Bo-Young Hur et al (1996) and Weiss et al (1997) tried to measure the change in pH value or concentration of H + of the solution in order to monitor the corrosion process of a Mg alloy. For example, Bo-Young Hur et al (1996) and Weiss et al (1997) tried to measure the change in pH value or concentration of H + of the solution in order to monitor the corrosion process of a Mg alloy.…”

Corrosion behavior and prevention strategies for magnesium (Mg) alloys

“…For example, Hur et al ( 1996 ) and Weiss et al ( 1997 ) tried to measure the change in pH value or concentration of H + of the solution in order to monitor the corrosion process of a Mg alloy. The pH method may be convenient in monitoring the corrosion of Mg alloys in a neutral solution in the initial stage.…”