Fasfältsmodellering: sprickinducerad urskiljning av en tredje fas i ett bimaterialsystem
- Claudio Nigro
- Malmö universitet
- Ansvarig vid Mau:
- Christina Bjerkén
- 01 februari 2018 - 31 oktober 2020
In structures made of advanced metals and composites materials, used e.g. in aerospace, nuclear power and medical applications, there can be a risk of failure as a consequence of their specific operating conditions. Typically, cracks are formed in components exposed to a harsh environment and mechanical loads during the working period. In bi-material systems, e.g. two-phase metals or composite materials, cracking can occur in and along the interface between materials or phases. This event can result in different types of deterioration processes such as delamination or second-phase formation, generally decreasing the mechanical properties of the materials. The formation of a second phase ahead of a stress concentrator, e.g. a crack, a dislocation or residual stresses, has been observed in many materials such as rust in steels or hydride formation in titanium and zirconium alloys. The high stress concentration, which prevails in the vicinity of the crack tip, is believed to be the driving force of the phase transformation.
The aim of the project is to use the phase field theory to model and study the effect of the presence of a crack lying in the interface between two different metallic phases on the formation of a third phase. Further, this work is meant to contribute to the prediction and, eventually, the prevention of failure of bi-material systems likely to form brittle phases.