According to the classification of squeeze, indirect squeeze casting was used in the experiment, and the “translational pouring pressure solidification” squeeze casting method with intellectual property rights was adopted. When the semi-solid slurry is poured into the translational injection barrel, it is closely connected with the bottom gate of the die after it is translational in place. When the punch is extruded, the liquid metal flows as the filling cavity, and the pressure is transferred to the part through the larger inner gate. The final shape of the part is determined by the shape of the cavity space sealed after mold closing, and the accuracy of the part size is high. The extrusion casting die is equipped with overflow groove, and the translational pouring pressure method is used to inject and pressurize from the bottom of the die, and the overflow groove is set around the upper plane of the part, which will be very conducive to exhaust and eliminate oxide and other inclusions, and effectively improve the production quality of the part. Because the bottom barrel is directly connected with the runner, it can not be less than the amount of filling the whole mold cavity, and the excess slurry can be solidified in the runner, so there is no very strict requirement for the pouring quantity. Of course, there should not be too much surplus, otherwise it will increase the waste, reduce the production efficiency, and affect part of the quality of the solidification process.
The forming process of rheo squeeze casting can be divided into three stages
(1) Preparation stage: mold preparation (including mold cavity cleaning, upper and lower mold inner wall coating spraying, mold heating control, etc.); equipment preparation: 300t j15-300 The main contents of this paper are as follows: the trial operation of the vertical squeeze casting molding machine, the cleaning, coating and preheating of the transfer barrel, the safe installation of the mold, the preparation of semi-solid metal slurry (including alloy preparation, smelting, degassing and slag removal, the preparation of the transfer tube, the preparation and debugging of the process parameters, etc.).
(2) Casting forming stage: the semi-solid slurry is poured into the barrel of the machine tool (it has been preheated to about 540 ℃), the equipment starts the cycle action, closing the mold and moving the barrel laterally to the bottom of the preheated mold, according to the set procedure for docking, pressure injection, pressure retaining, pressure relief, opening and ejection, and taking out the parts. The semi-solid slurry was prepared on the numerical control lspsf process equipment designed and developed in the laboratory.