Strength and fracture mechanism of nanostructured metal materials for medical applications

In this paper we study titanium Grade4, magnesium alloy Mg-Zn-Ca, corrosion-resistant austenitic steel 08Kh18N9 for medical applications. The mechanical properties in tension, torsional strength, and cyclic crack resistance under different types of loading of steels are investigated. The results are compared for two states of steels: the initial coarse-grained (CG) state and ultrafine-grained (UFG) state produced by severe plastic deformation processing via equal-cannel angular pressing (ECAP). It is demonstrated that the ultrafine-grained materials have essentially better strength and lower sensitivity to cyclic overloads. It is concluded that all the studied UFG materials are more promising compared to CG ones for the manufacture of medical devices for various purposes, which experience various static and cyclic loads during operation.