The influence of carbon nanotubes on the corrosion behaviour of AZ31B magnesium alloy

Carbon nanotubes (CNTs) are an effective reinforcement for magnesium (Mg) and its alloys due to their excellent mechanical properties. However, due to their quite different electrical properties compared to other carbon allotropes, the influence of CNTs on the corrosion of Mg is expected to be different. For this reason, the corrosion of AZ31B Mg alloy based composite with CNTs (AZ31B/CNT composite) was investigated with immersion tests, polarization tests and surface potential measurements. The galvanic corrosion between the Mg matrix and CNTs played an important role in the corrosion behaviour of the AZ31B/CNT composite.

Research highlights
► The immersion tests showed that AZ31B/CNT composites were severely corroded.
► The polarization tests revealed that harsh corrosion was progressed around CNTs.
► The SPD between the Mg matrix and CNTs was enough to form the galvanic cell.
► Corrosion products were accumulated along CNTs.