Composition optimization of Al-Ni-Ti alloys based on glass-forming ability and preparation of amorphous coating with good wear resistance by plasma spray

Al-based alloys with compositions of Al100-x-yNixTiy (x = 5, 10, 15; y = 3, 6, 9) and Al100-x-yNixTiy (x = 10; y = 12, 15) were prepared by single-roller melt-spinning. To overcome the inability to measure the glass transition temperature, the amorphous content calculated from the X-ray diffraction pattern was used to evaluate glass-forming ability. The optimized composition with the highest glass-forming ability was Al81Ni10Ti9. The microhardness of the Al81Ni10Ti9 ribbons increased first and then decreased when the ribbons were annealed at temperatures from 150 to 550 °C. Precipitation of α-Al nanocrystals improved the microhardness. There was no amorphous phase in the powders based on the optimized composition prepared by the atomization method, while the amorphous content of the coating obtained by plasma spray reached up to 49.76%. This was because the cooling rate in the spray process was at least two orders of magnitude higher than that in the gas atomization process. The coating had good wear resistance and the wear mechanisms were also analyzed. •A new method to evaluate the glass-forming ability (GFA) for alloys with low GFA;•A kind of Al-based amorphous coating was prepared by the plasma spray technology firstly;•The amorphous phase was not in the atomized powders but formed during the process of plasma spray;•Al-Ni-Ti amorphous coating possess good wear resistance and application prospects on surface engineering;