Investigation of the amorphous structure and hydrogen-induced mechanical behavior in V-Al alloys

Abstract This study explores the capability of V-Al alloys to form an amorphous structure using molecular dynamics simulations, focusing on the effects of cooling rates and atomic compositions. The results demonstrated that the V 50 Al 50 alloy forms a well-amorphous structure at cooling rates of 10 12 K/s or higher, with a glass transition temperature increasing with cooling rate. Radial distribution function analysis revealed medium-range order, and Voronoi polyhedra analysis indicated a densely packed amorphous matrix, particularly for faster cooling rates. Increasing Al content disrupted local ordering, while Al-poor samples exhibited more ordered structures, which may enhance stiffness and resistance to deformation. The effect of hydrogen incorporation was also examined, revealing a softening effect in the V 90 Al 10 MG, where hydrogen impurities decreased the overall strength. Interestingly, the softening effect was less pronounced in the equiatomic V 50 Al 50 alloy, where similar strengths were observed between the hydrogenated and non-hydrogenated samples. These findings highlight the potential of V-Al alloys to form metallic glasses that could be used in hydrogen storage applications.