Abstract
A bending-type fatigue testing apparatus designed for the fatigue test in vacuum was manufactured for the experiment. The alternate bending stress was applied to a specimen by electrodynamic conversion. Tests were performed in air (1.0×101Pa) and in vacuum of 5.3×10-3Pa atmosphere for the notched plates of an AZ31 magnesium alloy. The fatigue life in vacuum (Nf)V was longer than that in air (Nf)A. The ratio of (Nf)V/(Nf)A tended to increase with the decrease in the stress amplitude. The increment of fatigue life in vacuum was observed at both crack initiation and propagation stages.
