The difference of strength between ferrous alloys (SS41, SCM3, S45C and SUH3) and cast irons (FC25 and FCD45) is the essential factor affecting the character and strength of bonded parts. As the difference of strength becomes larger, more dynamic superplastic flow is needed as far as the optimum bonding conditions are concerned. The present technique of dynamic superplastic solid-state bonding for same and/or different materials seems to embody possibilities for many applications such as partial reinforcement of engine-cylinder head or partial mending of cracks and/or casting defects.