Mold filling speed of squeeze casting

The composite squeeze casting method adopts the closed mold filling method, which is similar to the indirect squeeze casting. Therefore, the filling speed of the indirect squeeze casting is used as the design reference of the composite squeeze casting forming system. At present, experimental method or numerical simulation method is used to determine the mold filling speed at home and abroad. For example, Campbell J. et al. Found through various experiments that there is a critical entry velocity for castings with a certain alloy and a certain wall thickness. Beyond this velocity, various mechanical properties of the castings will be greatly reduced, and determined the critical entry velocities of several aluminum copper alloy castings with different wall thickness by experiments. For aluminum alloy castings, the critical inlet velocity of 5mm thick plate castings is about 0.5m/s, while that of 10mm thick plate castings is about 0.3m/s.

The numerical simulation methods of mold filling process mainly include simple method, MAC method, SMAC method, VOF method and SOLA-VOF method. SOLA-VOF method is the most widely used method in numerical simulation of mold filling process. Sola method is used to solve the velocity field and pressure field of fluid, and VOF method is used to deal with the free surface. In recent years, many scholars have been engaged in the research of numerical simulation technology of casting filling process, and continuously improved various methods, which can basically achieve the basic agreement between simulation and experiment.

After the key technical parameters are determined, the system can be designed according to the production system design theory. The composite squeeze casting forming system for large parts is composed of composite squeeze casting equipment and peripheral devices. It is an organic whole composed of hardware and software involved in the composite squeeze casting forming process, and has obvious system characteristics. Aiming at optimizing the forming process of squeeze casting, dengjianxin proposed that the overall design method of squeeze casting forming system be divided into three subsystems, namely, mold design subsystem, process parameter design management subsystem and squeeze casting equipment subsystem. The system is a small test system with a clamping force of 250 tons. Although it can not be used to form large parts, the system design method has certain reference value.

The research objective is to design and manufacture the composite extrusion system, melt conveying system and floating rigid support die for large parts, integrate the transformed 1600 ton indirect extrusion casting equipment, form a composite extrusion casting forming system for large parts, and finally form qualified large wheel hub parts.