Corrosion fatigue of a magnesium alloy in modified simulated body fluid

• This article reports corrosion fatigue of a Mg alloy in modified simulated body fluid.
• There is a considerable reduction in fatigue life when tested in m-SBF.
• During fatigue in air, the cracking initiates at inclusions, but in m-SBF, it is enhanced due to pitting.
• Hydrogen embrittlement plays a dominant role in cracking when tested in m-SBF.

For magnesium (Mg) alloys to be used as temporary biodegradable implants it is essential to establish their resistance to body fluid-assisted cracking. In this paper the fatigue behaviour of a common magnesium alloy, AZ91D, is studied in air and in modified simulated body fluid (m-SBF), and the effect of different electrochemical conditions on corrosion fatigue life is investigated. The alloy was found to be susceptible to corrosion fatigue. Results suggest inclusions and corrosion pits to be the crack initiation sites, and hydrogen embrittlement to play a dominant role in cracking of AZ91D Mg alloy in m-SBF.