|About this Abstract
||2011 TMS Annual Meeting & Exhibition
||Bulk Metallic Glasses VIII
||Transition from Strong-Yet-Brittle to Stronger-and-Ductile by Size Reduction in Metallic Glasses
||Dongchan Jang, Julia R Greer
|On-Site Speaker (Planned)
A combination of high strength and extended deformability of materials is favorable for engineering applications, as the former assures optimal performance under extreme environments while the latter increases the reliability by protecting the system from a sudden breakdown. In this work we report the attainment of both high strength and superior deformability in Zr-based metallic glass by using sample dimensions as key property-controlling parameter. We report that once the lateral dimension is decreased to 100 nm, the formation of shear bands seizes, and the material shows significant homogeneous plasticity (25%) while maintaining its high strength (2.25 GPa). Furthermore, unlike in other engineering materials, we observe a distinct difference between the transition from lower, bulk-like strength to higher one and that from brittle to ductile deformation, as strength and ductility appear to be de-coupled in these metallic glass nano-pillars. A phenomenological model for size dependence and brittle-to-homogeneous deformation is provided.