High precision measurement of thermophysical properties for liquid metals - Requirements for simulation of foundry processes

摘要

Casting simulation software programs generally offer the foundryman powerful tools for a computational optimisation of his foundry processes. According to the numerous casting techniques, special calculation modules for all common casting procedures, which are adjusted to the respective process peculiarities, are necessary. A comprehensive and reliable material database connected to the simulation software, which contains the ihermophysical and thermomechanical data of the different materials, is needed to guarantee accurate calculations. Continued revisions and updates of the present datasets are carried out to further improve the simulation potentialities, and basic research is needed to obtain new findings. The paper describes the requirements for and the sensitivity of the thermophysical data for the casting simulation. The application of modem measurement equipment enables most accurate determination of the material properties for the liquid and partly molten state. New data for this temperature range shall be measured in the frame of an ESA funded research project by DLR. The thermophysical property measurement will be carried out by means of the electromagnetic levitation technique, so this method will be described in this paper. The measured data will be used for the simulation of foundry processes, and the influence on the quality of the results will be investigated. It is expected that the availability of accurate measured thermophysical data for the partly molten and the liquid state of the cast materials will enhance the continued improvement of material database for the process simulation. As a result, improved numerical simulation of casting processes will be possible, helping the foundryman to further optimise and develop his foundry activities.