Mechanistic Design of Hierarchical Multilayered Metal-MAX Phase Nanolaminates

We investigate the deposition, microstructure, and mechanical properties of unique hierarchical multilayered metallic (Nb, Ti) and MAX phase (TI₂AlC) Nanolaminate (MMN) systems where the interface between metal and MAX phase layers are in direct competition with the internal interfaces within the MAX layers. We utilize conventional magnetron sputtering, as well as a unique twin chamber atomic layer deposition and physical vapor deposition system that enables deposition in both chambers without breaking the chamber vacuum to explore various pathways to deposit MMN while minimizing the interlayer diffusion of atomic species. Transmission electron microscopy investigations confirm the presence of Ti₂AlC and Ti layers, and selected area electron diffraction analysis reveals the nanocrystalline nature of the deposited layers. Subsequent micro-pillar compression demonstrates an 150% increase in stress across 10% strain after yield compared to micro-compression on nanocrystalline Ti₃AlC₂ MAX phase which demonstrated a 110% increase in stress across only 1% strain after yield, suggesting higher strain accommodation in the MMN. Concurrent modelling efforts observe similar behavior and support our Ti₂AlC MAX phase potential for future modeling of MMN.