Metal forming process control via computer simulation has gained wide acceptance over the last several years. The die casting process is a well known manufacturing process [1,2,3]. The process chain in the development of a die casting consists of functional design, digital mock up, detailed design, optimization of the casting process, manufacture of prototypes, layout of the series casting process parameters and tools design. All these steps can be supported by CAE technologies such as 3D-CAD, FE analysis and casting simulation by FEM. In this sense attempts has been made by many researchers in the fields of numerical simulation for die casting control [4,5,6,7,8]. For that FEA is applied not only for structural castings with complex geometries, but also on components that seem less demanding but require good surface finish to meet specific requirements.

The simultaneous engineering for modelling and simulation, aided by rapid prototyping (RP), establish itself especially in the product development process. As soon as the first product design is available, the first simulation calculations can be carried out and a RP model could be made for evaluation.

With the CAD data one can optimize the casting parameters for die casting starting with the PQ diagram, i.e., from the allowable working area below the machine's characteristic power line. For die casting process, the metal pressure (according to Bernoulli) and the plunger velocity should be optimized by simulation analysis or by analysing the real parameters registered via a data logger. The required flow rate is mainly determined by the die filling time, which must be optimized considering the casting volume, the selected alloy and the flow resistance.

The die filling and solidification behaviour is strongly dependent on the die's temperature field which can be simulated for optimization. To define a quasi- stationary temperature field within the die, several casting cycles can be calculated.

In this work, an optimized process control is developed, which is supported by a completely integrated chain of CAE technologies including 3D-CAD, casting simulation with finite element analysis (FEA), and rapid prototyping (RP). This R&D is confirmed through a die casting case study to produce good quality die cast parts.

The first simulation with the preliminary geometry of the part in 3D-CAD proves that the part thickness varied too greatly, consequently the design was remodel for optimization, with a more uniform thickness to improve the filling and cooling during alloy solidification.

The simulation offered the flexibility to analyse the temperature profiles at various stages in the casting cycle. Analysing the temperature distribution, during solidification process, it is confirmed the location of some hotspots, which originate some porosity owing metallic contraction.

The numerical simulation and FEA was allowed optimizing the parameters in the hot chamber die casting process to produce thin-walled parts. The casting design was improved to avoid swirls and turbulence during melt flow. An optimized continuous runner and ingate system was design from the simulation results.

A series of die castings experiments was conducted. The shot filling tests proved that the process control parameters optimized from simulation results matched the real die casting results very well. Good quality parts with sound microstructure were produced based on the optimized design.

1

Street, A.C., "The Diecasting Book" 2nd Edition, Portcullis Press, 3-17, 1986.

2

Herman, E.A., "Die Casting Process Engineering and Control", Society of Die Casting Engineers, Inc., River Grove, Illinois 60171, 1988.

3

Herman, E.A., "Die Casting Dies: Design", North American Die Casting Association, 15-24, 1992.

4

Hu, B.H., Hao, S.W., Niu, X.P., Tong, K.K.S., Yee, F.C., "Optimization of Mould Design in Die Casting of Pewter Parts through Numerical Simulation", Proceedings of International Conference on Mechanics of Solids and Materials Engineering, Singapore, Vol. A, 235-240, 1995.

5

Venkatesan, K., Shivpuri, R., "Numerical Simulation of Die Cavity Filling in Die Castings and an Evaluation of Process Parameters on the die Wear", Transactions of the 17th International Die Casting Congress and Exposition, Ohio, USA, 1-11, 1993.

6

Frayce, D., Hetu, J.F., Loong, C.A., "Numerical Modelling of filling and Solidification in Die Casting", Transactions of the 17th International Die Casting Congress and Exposition, Ohio, USA, 13-17, 1993.

7

Osborne, M.A., Mobley, C.E., Miller, R.A., Kallien, L.H., "Modelling of Diecasting Process using Magmasoft", Transactions of the 17th International Die Casting Congress and Exposition, Ohio, USA, 77-84, 1993.

8

Kallien, L.H., Lipinski, M., "Optimization of Die Casting Parts using Numerical Simulation of Die Filling and Solidification", Transactions of the 17th International Die Casting Congress and Exposition, USA, 85-89, 1993.

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