Ing. Pavel Šotka
Simulation of casting, alloy solidification, temperature balance
Virtual techniques are increasingly important in the production of metallurgical tools. SW ProCAST from ESI Group has been fully used for this purpose since 2014 (note: SW MAGMA, installed in metallurgical operations, was used indirectly in the past).
Numerical simulations serve to optimize existing tools, but the main benefits of simulation in a virtual environment arise in the development of new pressure forms. Even before starting the material preparation of production, it is possible to model the pressure mold and observe how the design and technological plans will affect the quality of the resulting casting.
An important basis for achieving realistic simulation results is the detailed measurement of parameters in the production process and their correct interpretation when setting boundary conditions. Currently, the simulation matches reality 85-90% of the time. Greater accuracy of the simulation can be ensured by a higher degree of validation of boundary conditions, by increasing the computational capabilities of SW and HW and, last but not least, by deepening the experience of experts.
The foundation of a successful virtual die-casting process is a mold model close to a real tool working in real conditions. The mold clamped on the machine in the foundry has a diverse temperature field. We approach this state in a virtual environment by simulating cycles.
Just like in reality, in each casting cycle there is a thermal equilibration between the casting and the mold until the temperature field of the mold stabilizes after a certain time. This is the starting point in the simulation for subsequent mold filling and casting solidification calculations.
The simulation of the filling of the mold cavity is used to verify the correctness of the design of the geometry of the inlet system and the venting system. The movement of the melt through the cavity is monitored, and in the course of it, places critical for the formation of foundry defects in the casting are assessed.
Simulation of material solidification
The simulation of casting solidification makes it possible to analyze the transformation of the melt into a solid phase in a virtual environment. Other specific types of foundry defects arise during solidification, which can be detected by numerical simulation. With a detailed analysis, the reasons for the defect can be determined, and the possibilities for remediation can then be addressed.