Abstract
The fatigue behavior of 2A12 Aluminum alloy was experimentally studied through different annular notched specimens under symmetrical triangle with the frequency of 0.5 Hz. The experimental result showed that the microstructure played an important role during the entire fatigue life of 2A12 Aluminum alloy. The short fatigue crack only initiated due largely to the second-phase particle such as the S phase (Al2CuMg), the θ phase (CuAl2) and especially the black impurity phases debonding from the basal body when the fatigue cycle was sufficient. Most of crack initiation were related to the oversize particles and affected by the shape and size of the particles. The crack propagated along the slip band of the grains. The propagation morphology presented as a zigzag path in crystallography crack. The computed tomographic images were improved with image processing including contrast enhancement and outliers remove. These image processing procedures and three-dimensional reconstruction method were integrated into self-programming by using Matlab. The reconstruction result showed that the size and morphology of three-dimensional reconstructed crack had a satisfying agreement with the experimental ones.
