Gravitational macrosegregation in binary Pb-Sn alloy ingots

摘要: A space shuttle experiment employing the General Purpose (Rocket) Furnace (GPF) in its isothermal mode of operation is manifested on MSL-3, circa 1989. The central aim this to investigate effect reduced gravity levels segregation behavior a slowly, and isothermally, cooled sample binary Pb-15 wt pct Sn alloy. This should be able simulate, small laboratory sample, some aspects phenomena occurring large industrial ingots. Ground-based experiments conducted single-cavity simulator GPF, support microgravity are described detail. results MSFC compared with other related at Case Western Reserve University (CWRS), wherein constraints were relaxed. isothermally processed samples indicate gradual increase fraction eutectic, corresponding tin content, from bottom top ingot. radial variations minimal near ingot bottom, but there half. In CWRU experiments, more severe segregations, including defects known as freckles. Follow up GPF without constraints, or suitably modified hardware suggested.