Fracture mechanism of a coarse-grained magnesium alloy during fracture toughness testing

The fracture mechanism during fracture toughness testing has been investigated on a coarse-grained magnesium alloy, with an average grain size of 50 m, and a low fracture toughness. The results show that {1012}-type deformation twins are formed at the crack tip and many dislocations pile up on these boundaries. The accumulated strains at these boundaries become the origin of fracture; i.e. cracks propagate along these boundaries between the deformation twins and the matrix.