The cooling curves of typical flake graphite cast iron and nodular cast iron are shown in the figure. It can be seen from the figure that under the condition of the same casting section size and carbon silicon content, the undercooling required to generate flake graphite cast iron is lower than that of nodular graphite cast iron, that is, the driving force required to generate flake graphite is smaller than that of spherical graphite.
The results show that the vibration can increase the solidification undercooling of the alloy, that is, it increases the driving force for the crystallization of the cast iron alloy, which is conducive to the metal solidification process.
Therefore, by applying vibration and selecting appropriate vibration process parameters (vibration frequency and amplitude) in theprocess of cast iron alloy, sufficient undercooling can be provided for alloy solidification, that is, sufficient driving force for metal solidification. It can be concluded that it is feasible to change the graphite morphology in lost foam casting cast iron alloy by vibration from the thermodynamic point of view.