Unexpected thermal stability of dual-phase amorphous-nanocrystalline Al_(0.74)Mo_(0.26) alloy film prepared by annealing-induced crystallization

摘要

Dual-phase amorphous-nanocrystalline Al0.74Mo0.26 alloy film was fabricated by annealing-induced crystallization (AIC) in precursor of amorphous Al0.74Mo0.26 alloy film at 550 degrees C. The precipitated Al3Mo nano-grains with average size of similar to 5 nm was uniformly dispersed in Al-Mo amorphous matrix. Additionally, the dual-phase amorphous-nanocrystalline structure of the film was maintained even when the annealing process was performed above the crystallization temperature. The unexpected thermal stability of the dual-phase amorphousnanocrystalline Al0.74Mo0.26 alloy film resulted from effect of diffusion field impingement. Ham model was employed to quantitatively describe the kinetic stabilization mechanism of the film. Furthermore, the prepared film benefited from the combined effect of amorphous and nanocrystalline phase, which exhibited outstanding mechanical properties with elastic modulus and hardness as high as 240 and 17 GPa, respectively. Also, the film had extraordinary corrosion resistance with very positive corrosion potential, low corrosion current and stable passive state.