CORROSION FATIGUE OF MAGNESIUM ALLOY FOR ENGINE CRADLE

摘要

Magnesium alloys are among the best lightweight structural materials with a relatively high strength-to-weight ratio and excellent technological properties. AE44 is considered as to have better corrosion resistance characteristics. The object of this paper is to study the corrosion fatigue life of AE44 magnesium alloy under the corrosive environment of 3.5% weight fraction of salt water (3.5% NaCl solution), corrosion fatigue tests were carried out using MTS 809 material test system. Life cycle as a function of loading stress of 60MPa-140MPa at room temperature, with loading frequency of 1 Hz and R ratio of 0.1, showed the trend of influence of stress levels on life of the alloy. Corrosive environment did not significantly decrease fatigue life of AE44 die cast alloy, which implied that AE44 is not sensitive to salt water environment, but it was found that the anodic/cathodal reaction was very serious when there was leakage of salt water. An equation about AE44 on the fatigue life and stress relationship is applied based on the experimental results.