Mechanical Stability of a Diamond-like Carbon on a Nitinol Vascular Stent under Cyclic Loading

Hyun-Jong Kim, Myoung-Woon Moon, Kwang-Ryeol Lee, Hyun-Kwang Seok, Seung-Hee Han, Jae-Woo Ryu, Kyong-Min Shin and Kyu Hwan Oh
 

Failure behavior of a diamond-like carbon (DLC) coated on a nitinol vascular stent was investigated under a cyclic loading induced by a stent crimping system. It showed that fracture behaviors of DLC film were strongly influenced by the distribution of local strain on the stent due to a cyclic loading of contracting and expanding. Interfacial delamination of DLC films on stents was analyzed by the cross-sectional analysis of the fractured region using a FIB/SEM system. Interfacial adhesion strength was estimated with the spalled crack width of DLC films, which revealed that the adhesion was improved with respect to the thickness of Si buffer layer inserted between a DLC film and nitinol stent.