AZ91C magnesium alloy modified by Cd

• Addition of Cd did not bring the refinement of β-phase in AZ91C.
• Marginal increase in the mechanical properties (∼10%) to AZ91C.
• General corrosion behaviour of Cd containing alloys is worse than the AZ91C.
• Fine β-phase proved better resistant to corrosion as in the case of AZ91C.
• Effect of Cd on AZ91C is reported/discussed in detail.

In the present work, the effect of Cd on the microstructure, mechanical properties and general corrosion behaviour of AZ91C alloys was investigated. Addition of Cd was found not to be efficient in modifying/refining the microstructure or β-phase. A morphology change in β-phase from fine continuous precipitates to discontinuous β-phase upon the addition of Cd was observed. A marginal increment in mechanical properties was observed. General corrosion behaviour was followed with weight loss measurements, potentiostatic polarisation studies and surface studies in 3.5% sodium chloride solution and 3.5% sodium chloride with 2% potassium dichromate solution. Cd addition deteriorated the corrosion behaviour of AZ91C. This behaviour was attributed to the formation of chunks of β-phase upon the addition of Cd. AZ91C with refined β-phase distribution, performed rather better in the NaCl solutions.