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.