Spray formed Al-based amorphous matrix nanocomposite plate

A novel Al86Si0.5Ni4.06Co2.94Y6La0.5 amorphous matrix nanocomposite plate with a rough diameter of 200 mm and a maximum thickness of 12 mm has been prepared by spray-forming. The microstructure gradient is observed, with 91.7 vol.% amorphous phase for the bottom region, 78% for the middle, and 54.3% for the top. The nanoindentation tests reveal its high microhardness of ∼420 HV. The microstructure characterization indicates that the improved mechanical properties may be attributed to the homogeneously dispersed nano-scale fcc-Al in the amorphous matrix. This work further proved the feasibility of achieving substantial fraction of amorphous phase for bulk Al-based alloys by spray forming.