Study of crack driving force in TiNi shape memory alloy coating subjected to cyclic loading

The superelasticity effect of TiNi alloy occurred in a certain temperature range was the unique mechanical characteristics of shape memory alloy (SMA). Due to the existence of recovering force, this functional material can prevent or retard the crack growth at a high level. As an advanced coating material TiNi shape memory alloy will enhance the coating's toughness and prolong the service life of whole coating/substrate system. In the present paper the finite element method was employed to simulate the behavior of TiNi SMA coating. The strain fields and the crack driving force of TiNi coating containing surface crack were investigated and compared with the normal coating material. The advantage of TiNi coating was revealed which provides the fundamental mechanical knowledge for the application of TiNi SMA coating in engineering.