Effect of Mechanical Surface Treatment and Environment on Fatigue of Wrought Magnesium Alloys

The fatigue performance of two widely used wrought magnesium alloys AZ31 and AZ80 in extruded form was studied. Both shot peening and roller burnishing were found to improve fatigue life in air. When comparing air with aqueous NaCl solutions, AZ80 reacts more sensitively to an aggressive environment than AZ31. This influence becomes more pronounced if the surface is shot peened, but less pronounced after roller burnishing. This effect can be explained on the basis of differences in surface roughness induced by these mechanical surface treatments.