Thixoforming of steel offers the advantages of casting technology in combination with
high mechanical strength that can only be achieved by forging. The progress in establishing this
technology in industry depends on the success in the development of suitable steel grades.
Recent investigations dealt with the development of steel grades that are especially adapted to the
thixoforming process. For this, alloys were developed with a lower solidus temperature and a wider
process temperature range compared to classic forging steels. In consequence, the inductive heating
process is more tolerant to inaccuracies and for a given liquid fraction the process temperature
window is easier to handle.
It is desired to obtain great degrees of deformation at rather low forming forces as these parameters
determine the size of the needed presses. This behaviour is affected by the present liquid fraction in
the slug and the heat transfer between work piece and die. It was detected that variations of the
forming force have a direct influence on the quality of the thixoformed parts.
In order to make the thixoforming technology of steels competitive versus other forming
technologies, the parts must show a favourable microstructure and thus, good in-use properties. In this
paper various solutions are compared.
The main results obtained in the optimization research, namely, the steel grades adapted to semi-solid
forming, the resulting process parameters and the mechanical properties of thixoforming parts will be
presented for two exemplary steel grades. By producing a real automotive part, thixoforging of steels
with regard to the adapted materials and to the ongoing industrial implementation of this process is
proved.
Review of Numerical Simulation of Microwave Heating Process
