Investigation of Al-20Sn-10Cu alloy directional solidification by laboratory X-radiography

Abstract Al-based alloys with a soft phase such as Sn are extensively used for bearing components due to their self-lubricating properties. Al-Sn lack the ability support heavy loads so alloying Cu third element provides solution strengthening of aluminium matrix. A crucial issue in manufacturing Al-Sn-Cu is miscibility gap diagram system. Liquid immiscibility responsible severe segregation during solidification process, large density difference between Al-rich and Sn-rich liquids, which limits utilization industry. It therefore both scientifically technically important accurately understand path. In present work, ternary Al-20wt.%Sn-10wt.%Cu was investigated in-situ by using X-radiography. Directional experiments were performed on sheet-like samples laboratory device SFINX (Solidification Furnace IN-situ X-radiography), consists Bridgman-type gradient furnace an X-radiography The sequence determined based observation recorded images, enlightening successive steps These observations compared predictions obtained from thermodynamic calculations. Complementary post-mortem microscopic analyses showed that dendrite primary trunk secondary arms developed along <110> crystallographic axes instead usually expected <100>.