Effect Of Mechanical Vibration On The Hot Tearing Of ZL205A Alloy Castings By Low Pressure Casting Process

In this paper, the low pressure vibration casting platform is designed based on the principle of mechanical vibration and low pressure casting. By means of numerical simulation, the influence of fluctuating load on the temperature field, stress field and the thermal cracking of low pressure casting is studied. Taking ZL205 A alloy as experimental material, the effect of mechanical vibration on the thermal cracking of ZL205 A alloy casting is studied by using metal mold.The low pressure vibration casting platform includes four main parts, the vibration module, the low pressure module, the temperature measurement module and the mold module. The platform adopts inertial eccentric wheel vibration motor as a vibration source, according to demand can adjust the amplitude and the frequency of mechanical vibration, vibration temperature control based on the temperature measurement module.By the use of ZL205 A low-pressure casting process applied load fluctuation of the numerical simulation, found the load fluctuation can uniform temperature field, increasing the solidification time of the casting, casting solidification sequence changed. On the other hand, the load fluctuation can change stress field during the solidification of castings, in order to change the casting hot cracking tendency.Through the 12 groups of vibration low pressure casting test, the casting crack length of were measured by using the orthogonal analysis method to obtain the vibration frequency, vibration amplitude, casting size and the onset temperature of casting surface crackle size effect law. It is found that the influence of the diameter of the rod is the greatest, and the second is the vibration frequency, and the vibration amplitude is the smallest. From the table we can very easy to find the low-pressure casting applied optimal vibration parameters of mechanical vibration: when the vibration frequency is 15 Hz, amplitude is 0.5 mm, slender rod diameter is 30 mm, the onset temperature of 650 ℃, casting hot crack tendency is the minimum. The internal stress of the casting is obtained by measuring the amount of shrinkage and tensile elongation. The parameters of The smallest tendency of the heat cracking applied mechanical vibration on the low pressure casting are 0.5mm of the amplitude, 15 Hz of the frequency at high temperature.