When laying out the rigging system, a common question is how to evaluate the effectiveness of the measures taken. What effect, for instance, does choosing a larger feeder or changing the position of a chill have on the feeding process? By systematically making use of virtual designs of experiments, it is possible to answer these questions.
In Figure 1, you can see the rigging system of a ductile iron casting (EN-GJS-400) with possible positions of the chills and feeders including different feeder sizes. The simulation of a virtual test field does not only provide you with information about the best chill layout, feeder size and position, but also allows you to see which effect the varied variables have on the casting quality.
The virtual optimization of heat treatment processes allows:
Virtual experiments allow the systematic variation of tempering temperatures and times of steel castings, to find an optimal compromise between strength and ductility.
The calculation of the relief of residual stresses from the casting process, for example for stress relief annealing of iron castings, can be carried out. In cast iron, in addition to conventional stress relief annealing and pearlitization, the optimization of the complex production process to produce austempered ductile iron (ADI) is possible.
For structural components made of aluminum, among others, the design of heat treatment supports can be optimized with the help of residual stress calculations during heat treatment.
The risk of crack formation due to high temperature gradients during the quenching of castings can be minimized through corresponding process and design optimization.
Casting Distortions During Solution Treatment
Aluminum castings are often heat-treated to increase mechanical properties and simultaneously decrease thermal stresses induced by the casting process.