On the role of impurities on spheroidal graphite degeneracy in cast irons

Though manufacturing spheroidal graphite cast irons is a well-established industrial process, good nodularity which essential for mechanical properties may be hampered by several factors. Amongst them the presence of impurities at trace level lead to growth protrusions and question how they can destroy spheroidizing effect magnesium. For first time, it shown that such are present together with magnesium interface between spheroid protrusion. getting this result, site-specific electron transparent lamellae were prepared using Focused Ion Beam characterized nanometric scale atomic resolution scanning-transmission microscope. It also automatic crystal orientation mapping there no definite crystallographic relationship underlying spheroids.