Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1575368 | Materials Science and Engineering: A | 2014 | 8 Pages |
Abstract
Ti2AlC is a representative member of MAX phase materials, which are known to exhibit a unique combination of properties observed in conventional ceramics and metals. In this paper, experimental protocols for the high strain-rate compressive response (up to ~4700Â sâ1) using a Split Hopkinson Pressure Bar (SHPB) is developed. The optimized specimen geometry for Ti2AlC, derived in this work, ensures dynamic equilibrium and minimizes dispersion in the transmitted pulse. A modification of the conventional SHPB experimental set-up involves in situ high speed imaging, which facilitates identification of real strains free of macroscopic crack artifacts. Characteristics of the high strain-rate response of polycrystalline Ti2AlC, associated deformation mechanisms and micro-scale origins are presented. The results show that Ti2AlC shows significant inelastic deformation and strain softening before fracture, even at very high strain-rates. Post-fracture microstructures are analyzed to determine dominant deformation mechanisms which reveal simultaneous coexistence of kink bands and delamination, grain-pullouts and trans-granular cracks induced by high strain-rate loading. These deformation characteristics - also active under quasi-static loading, are responsible for the exceptional damage tolerance of Ti2 AlC and provide experimental evidence for high rate kink banding in MAX phases.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Riddhiman Bhattacharya, Rogelio Benitez, Miladin Radovic, Nakhiah C. Goulbourne,