Using our electrical biasing holder, researchers at Penn State have demonstrated the room temperature dislocation-based plasticity and tremendous flaw tolerance of TiN film, which in bulk form is a brittle material. TiN loading was conducted using a MEMS device containing electro-thermal actuators. The researchers surmise that room-temperature dislocation activities resulted from the nucleation of pre-existing dislocations, which resulted from residual compressive stresses developed during deposition. As a result, the TiN films were tougher than the Ti films in the tested multilayers. The movie shows the dislocation movement at the crack tip following loading at room temperature.

Reference: S. Kumar, D.E. Wolfe, M.A Haque. “Dislocation shielding and flaw tolerance in titanium nitride,” International Journal of Plasticity 27:5 (2011) pp. 739–747 . Abstract

Movie copyright © 2010, Elsevier Ltd.  All rights reserved.