Effect of processing parameters on the relative density of spray rolling 7050 aluminum alloy strip

Spray rolling is a novel metallic semisolid near-net-shape forming technology. The problem of controlling the density of spray rolling aluminum strips is taken into two considerations: eliminating porosity before rolling and providing enough thickness reduction ratios during rolling. This simulation study reveals the relationship among the processing parameters of spray rolling, average solid fraction, and the relative density of a strip. The calculated values agree well with the experimental data. The densification mechanism during spray rolling process corresponds to the removal of porosity dominant regime. The relative density of spray rolling aluminum alloy strip depends heavily on both the solid fraction and thickness reduction ratios. The solid fraction in the range of 65-70 % corresponds with a good spray deposition condition and a high density level of strips. The present theoretical and experimental analyses suggest that spray rolling can be optimized to manufacture directly strips with a high density and excellent mechanical properties from liquid metal within one step.