An in-situ study of formation of compact graphite during solidification of cast iron using X ray tomography and radiography

Formation of compact graphite was studied in experiments where ductile cast iron samples were repeatedly melted and solidified. In each cycle, the Mg-treatment faded leading to a gradual change in graphite shape from nodular shape to compact graphite and eventually flaky graphite. In situ X-ray observations of nucleation and growth of compact graphite shows how the graphite nucleates as individual, nearly spherical particles that form protrusions in the interdendritic space, and eventually merge to form large 3 dimensional networks of compact graphite aggregates