The vibration solidification equipment used in the vibration lost foam casting is a two-way electromagnetic vibration table with the model of bf-ld-tf developed by Dongguan bell Test Equipment Co., Ltd. During vibrating pouring, the sand box shall be placed on the loading platform of the vibrating table and fixed with bolts. During pouring, the sand box moves synchronously with the stage, that is, the sand box is a forced vibration under the action of the shaking table.
The existing research results show that the vertical vibration has a great influence on the microstructure and properties of the alloy during lost foam casting. Therefore, the vibration direction of the test design is vertical.
In the solidification process, the solidified crystal on the surface of lost foam casting mold will make forced vibration with the shaking table, and make equal amplitude reciprocating motion relative to the equilibrium position at rest. Its motion equation can be expressed as:
Where, s is the displacement, mm; B is amplitude, mm; T is the time, s; F is the vibration frequency, Hz- Φ Is the initial phase, RAD; The minus sign indicates that the initial vibration position of dendrite lags behind the phase of vibration source.
The velocity and acceleration of the solidified melt moving with the shaking table can be obtained by deriving the formula from time:
The parameters such as amplitude and frequency are designed according to the motion equation of the shaking table, and then the parameters such as acceleration during metal solidification are determined according to the amplitude and frequency.
During the experiment, the vibration amplitude of 3mm was selected to control the solidification structure of cast iron alloy by changing the frequency in the process of lost foam casting. The vibration frequencies were 0, 35, 50 and 100Hz respectively. The effect of vibration frequency on the microstructure and properties of lost foam casting cast iron alloy was studied.
Under the optimized vibration frequency, the amplitudes of 0.75, 2, 3 and 4mm in the process of lost foam casting were changed to study the effect of amplitude on the microstructure and properties of lost foam casting cast iron alloy.