Nanocrystalline multilayer thin-films are manufactured in configurations of alternating porous ceramic (TiN) layers of relatively high thickness (hceramic) with metal (Ti) layers of low thicknesses (0.8 nm < hmetal < 34 nm) and keeping a constant modulation ratio (η ∼ hceramic/hmetal ∼ 17.5). As hmetal decreases, the overall co-deformation mechanism in the multilayer films bifurcates into the dislocation dominant confined layer slip (CLS) mechanism in the metal and diffusional creep dominant processes in the porous ceramic layer at hmetal ∼ 6.7 nm. This bifurcation leads to simultaneously achieving the highest strain hardening rate due to the CLS mechanism in one layer and the highest strain rate sensitivity value due to the diffusional flow in the other and overcoming the strength-ductility paradox in multilayer thin-film materials at low temperatures.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)