The effects of vibration frequency and molten iron treatment temperature on graphite morphology and primary phase of vermicular graphite cast iron in lost foam casting were studied. Vibration solidification and high liquid iron treatment temperature both make the graphite morphology of vermicular cast iron change from vermicular to vermicular fledgling or flake, and reduce the hardness value of vermicular cast iron. With the increase of vibration frequency, the content of equiaxed grains in primary austenite increases, and the length of lamellar graphite between dendrites tends to be shorter.
The effect of sample wall thickness on graphite morphology of vermicular graphite cast iron was studied. When the sample wall thickness decreases, the vermicular graphite content decreases and the globular graphite content increases due to the accelerated solidification rate of cast iron alloy. Moreover, the smaller the sample wall thickness, the less ferrite content in vermicular cast iron.
The feasibility of controlling graphite morphology of cast iron by vibration solidification was analyzed by means of thermodynamics and dynamics. The graphite morphology of cast iron alloy lost foam casting parts can be properly controlled by combining appropriate vibration solidification with lost foam casting process parameters.