Vertical Indirect Squeeze Casting Process Of A Large Aluminum Alloy Frame Part With Electromagnetic Pump

Squeeze casting is a precision fabrication technology, which combined casting and forging processes. The casting solidification is promoted under high pressure within a reusable die, therefore, squeeze casting has many advantages such as porosity reduction, fine grain size microstructure, improvement of mechanical properties and near net shape castings. Electromagnetic pump can be used for casting process to transfer molten metal. This technology integrated in squeeze casting process has many advantages as the following: the molten metal flows smoothly with electromagnetic pressure and in a closed channel, therefore, oxidation and gas entrainment were reduced effectively; the velocity and volume of the molten metal can be controlled accurately and continuously; the casting microstructure and property are improved after molten metal passing through the magnetic field, and so on. The Aluminum alloy supporting frame referred to this paper has large scale, complex structure and requirement of high mechanical properties, and the electromagnetic transfer system was used for the indirect squeeze casting process of the frame.The T-junction channel used for the electromagnetic transfer system was designed, then liquid metal flows from the channel to the shot sleeve was simulated with software FLOW-3D. The simulation results were investigated, and the molten metal's flowing behavior was discussed and then the generation of surface defect and air entrainment was analyzed. The results have shown that the larger of the fillet radius, the fewer of the surface defect and entrapped air. According to the numerical results, the transfer channel structure for the electromagnetic transfer system was designed. It was shown that few oxide defect and air entrainment was generated during the molten metal flowed from the furnace to the sleeve under the design.The molding filling process of the supporting frame was simulated with software JSCAST with initial molten aluminum temperature of 750℃, injection velocity of 0.04m/s, dies temperature of 280℃and cores Temperature of 300℃. The location of the last filling and pre-solidification were predicted. The solidification process after the filling was simulated, and the temperature evolution of 6 points in sequence of from the casting edge to the biscuit in the casting were recorded. The results showed that the casting solidification is in order of the edge to the central part and then to the biscuit. This is very helpful for the transfer of the squeeze pressure from the punch. The numerical results have shown that the selected parameters are reasonable. According to the results, vents and overflows were designed and then the dies were produced with H13 steel.The vertical indirect squeeze casting process of the ZL101 Al alloy supporting frame with electromagnetic transfer system was trial-produced. It was found that the electromagnetic transfer system can transfer the molten alloy reliably and the alloy was automatically flowed from the transfer channel to the furnace during the casting solidification process. The castings were trial-produced successfully. It was found that surface of the castings is good and defects such as misrun or cold lap were not found. All these results indicate the feasibility of the designed electromagnetic transfer system, the designed die structure, and the parameters of the indirect squeeze casting process.