Structure and property transitions of Al-based binary alloy coatings by magnetron sputtering

Al–M (M = Ti, Cr, Mo, W) alloy coatings were subjected to DC magnetron sputtering by a rapid method to analyze the evolution of coating structures with composition. Pure Al and M targets were used to deposit coating arrays across the entire binary range of Al–M alloys. All Al–M alloys exhibited a specific amorphicity range. Al–Ti and Al–Cr alloys were completely amorphous, whereas Al–Mo and Al–W alloys possessed a range of amorphous–crystalline mixtures. Results revealed that Al–Ti alloys had the widest amorphicity range. Nanoindentation tests indicated that the hardness and modulus of amorphous alloys were higher than those of solid solutions for Al–M alloys.