Category Archives: Fracture mechanics

Martensitic phase transformation and fracture

As the relatively ductile austenite phase is transformed in to harder and more brittle martensite in the vicinity stress-concentrations, the material conditions change and also the conditions for crack formation and propagation. Fatigue fracture can be considerably influenced by this kind of diffusionless phase transformation due to the higher fracture strength of martensite, compared to that of austenite. In Hallberg et al. (2012) the influence of martensite formation on fracture behavior and crack tip conditions is investigated, as illustrated below.

Transformed zone at the tip of a stationary crack. The crack tip is located at coordinates (0,0). The contour lines in each figure correspond to different load levels. a) T=213K and b) T=233K.
Transformed zone at the tip of a stationary crack. The crack tip is located at coordinates (0,0). The contour lines in each figure correspond to different load levels. a) T=213K and b) T=233K.