Casting process simulation from one mould

Topic of the month - February 2015

Metal casting is amongst the oldest production processes of mankind, and has been used for a good 5000 years. For a long time, casting processes and cast products were exclusively further developed through experimentation and experience.

By modelling current, heat flow and tensions, today, the casting process simulation gives a deep understanding of the ongoing processes, and provides knowledge which was not previously available.

Casting process simulation

Casting process simulation is the computer aided modelling and analysis of the processes during casting, with the help of a special calculation software.

It defines the process sequence of casting and solidification, based on physical-mathematical models, as accurately as possible, with boundary conditions for the calculation. As a result, you get illustrations of the process, from mould filling, solidification, microstructure and characteristic formation, to the formation of internal stresses and distortion of the cast parts.

© MAGMA Gießereitechnologie GmbH

Mould filling for a pump casing simulated in MAGMA5 © MAGMA Gießereitechnologie GmbH

For the modelling, homogeneity means: Considering numerous technical, physical and chemical variables, which mutually influence each other. A casting process simulation should be used as early as possible in the casting development process, in order to recognise critical areas, which can arise even during the design and construction of the component.
© MAGMA Gießereitechnologie GmbH

Forecast of microstructure and characteristics © MAGMA Gießereitechnologie GmbH

While previously, special and expensive computers were necessary for the elaborate simulations, today, high-performance PCs are standard hardware for the casting process simulation. Physics is increasingly integrated into the programmes, models are becoming more comprehensive and precise, and results should be available earlier and earlier.

So computer performance still counts. If simulation programmes are parallelised however, the enormous performance potential of parallel computers with multi core technology can be exploited. With suitable software on these computers, "experimenting on the screen" and automatic optimisation become a reality. Ultimately, the caster needs a reliable simulation programme, which is continually tested, checked and improved.

CAE (Computer-Aided Engineering)

Meanwhile, simulation has been generally accepted as a CAE method in the foundry industry, and industries that use castings, which are still growth markets. "We have looked intensively at the question: How can a simulation tool be optimally used in a typical small business industrial environment?", says Dr.-Ing. Jörg C. Sturm, Managing Director of MAGMA Gießereitechnologie GmbH in Aachen.

There is no doubt that significant cost savings can be achieved using casting simulation. "90% of the customers are foundry operations", points out Jörg C. Sturm. "The classic use of the casting process simulation takes place in the work preparation, in order to support the casting design of the future casting early on.”

This includes defining the gating and feeding technique and the mould design. On the one hand, it is about making the layout of the casting process process-reliable with the software, to be able to produce the desired quality safely, and at the desired cost. On the other hand, the simulation tool is used to influence component characteristics of castings in a needs-oriented and very targeted manner.

As we know, casting has the equal advantage and disadvantage that a lot happens in a production step. This results in the fact that the resulting component characteristics are very sensitive to the relevant process used.

Sturm points out what is special about MAGMA: "We can forecast these characteristics locally - for example, whether the material used has the potential to optimise the component, with regards to lightweight construction." Thus, for example, every casting has cooling related tensions, which arise as a result of the manufacture. They must be considered in the loading conditions.

© MAGMA Gießereitechnologie GmbH

Mould filling in the tilt casting process, simulated in MAGMASOFT® (image with the kind permission of PSA, France) and process diagram from MAGMA5 © MAGMA Gießereitechnologie GmbH

When asked about the quality of the material models, Sturm says: "Our approach is to consistently compare the forecast with the reality. Any further development at MAGMA is closely linked to the validation from the customer."

Robust processes and optimised solutions

With the latest developments, the old dream of using the computer to directly optimise casting processes and the casting quality is a reality today: "Virtual experimentation, i.e. using the computer to test different variables of the component quality or economic viability, without carrying out extensive real trials, is now automatically, completely supported by the software", says Sturm of the new method.

To do this, statistical experimental design methods are linked with the simulation, to identify the variables that have a significant influence on casting quality and economic viability, with a larger number of varying casting and production parameters, in a target oriented way.

"In this way, the robustness of processes and even an optimised casting technique or production parameters can now automatically be calculated by the simulation, even during the development of a casting."

It is precisely these possibilities of setting the optimum process window, even in the development process, which lead to the application level and depth of simulation results continually increasing within the foundries, but also with casting designers and casting users.

© MAGMA Gießereitechnologie GmbH

Virtual experimentation in MAGMA5 leads to an optimised casting technique and a robust production window © MAGMA Gießereitechnologie GmbH

The MAGMAacademy

With the motto "knowledge creates added value", alongside the programme and the additional services, the company also offers a comprehensive further training programme, for casting process simulation.

In training sessions, workshops and seminars at the MAGMAacademy, employees and managers learn how they can optimise development processes, reduce production costs and increase resource efficiency in their company, with the casting process simulation.

© MAGMA Gießereitechnologie GmbH

Training sessions, workshops and seminars are offered at the MAGMAacademy, on numerous topics relevant to foundries, in connection with casting process simulation © MAGMA Gießereitechnologie GmbH

These training sessions and further training events by MAGMA GmbH take place in the MAGMAacademy training centre in Aachen. Here in Aachen, the idea was "born", to develop casting process simulation as a tool for quality improvement, energy and cost saving.

MAGMA is the only company which exclusively deals with the virtual optimisation of casting techniques worldwide. A large part of the more than 200 employees worldwide are metallurgists and foundry engineers. With more than 1,500 industrial customers, MAGMA is bound by a firm partnership.

It is based on reliability, competence and an open, constructive customer communication, which is strengthened by continual user meetings, seminars and training sessions. The company and the software actively support customers, in complying with the challenges of the market, and securing a sustainable competitive advantage.

Frank Lindner