The Corrosion Behavior of AZ91D Magnesium Alloy in Simulated Haze Aqueous Solution

Liying Cui,Xiaogang Li,Bin Jiang,Peng Hu,Zhiyong Liu,Jiamin Shao,Cuiwei Du

doi:10.3390/ma11060970

Liying Cui, Xiaogang Li + Show 5 more

Open Access

https://doi.org/10.3390/ma11060970

Copy DOI

Abstract

The corrosion process of AZ91D magnesium alloy in simulated haze aqueous solution has been studied by electrochemical measurements, immersion tests and morphology characterization. Results show that AZ91D was corroded heavily in simulated haze aqueous solution due to the loose and breakable product film on the surface providing little corrosion barrier. The effect of different ions was investigated. It was found that both and played an important role in the corrosion process. helped to form passive film to protect the matrix, yet consumed OH−, resulting in the absence of Mg(OH)2 and serious corrosion. Meanwhile, and Cl− had influence on pitting corrosion. Magnesium aluminum oxide and MgAl2(SO4)4·22H2O instead of Mg(OH)2 were the dominate products, which is different from the former study. Corrosion rate changed with time, especially in the first 3 h. A two-stage corrosion mechanism is proposed after considering both the corrosion process and the influence of ions.

Highlights

Magnesium and its alloys are attractive in aerospace, automotive and electro-communication fields due to their abundant reserves and advantageous properties, such as excellent cast ability, high strength-to-weight radio and high damping capacity [1]
It shows that AZ91D is a two-phase In Figureof1,α-matrix the microstructure alloy1)
The Corrosion Behavior of AZ91D Alloy in the Simulated HA Solution

Summary

Introduction

Magnesium and its alloys are attractive in aerospace, automotive and electro-communication fields due to their abundant reserves and advantageous properties, such as excellent cast ability, high strength-to-weight radio and high damping capacity [1]. All these have made magnesium alloys promising metallic materials, the unwise use of magnesium in wet environments gives rise to its poor corrosion reputation [2]. Magnesium will form a product hydroxide/oxide film when exposed to aqueous environments [17].

Objectives

Methods

Results

Discussion

Conclusion