ISSN:
1662-9779
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Physics
Notes:
Thixoforming of steel offers the advantages of casting technology in combination withhigh mechanical strength that can only be achieved by forging. The progress in establishing thistechnology 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 thethixoforming process. For this, alloys were developed with a lower solidus temperature and a widerprocess temperature range compared to classic forging steels. In consequence, the inductive heatingprocess is more tolerant to inaccuracies and for a given liquid fraction the process temperaturewindow is easier to handle.It is desired to obtain great degrees of deformation at rather low forming forces as these parametersdetermine the size of the needed presses. This behaviour is affected by the present liquid fraction inthe slug and the heat transfer between work piece and die. It was detected that variations of theforming force have a direct influence on the quality of the thixoformed parts.In order to make the thixoforming technology of steels competitive versus other formingtechnologies, the parts must show a favourable microstructure and thus, good in-use properties. In thispaper various solutions are compared.The main results obtained in the optimization research, namely, the steel grades adapted to semi-solidforming, the resulting process parameters and the mechanical properties of thixoforming parts will bepresented for two exemplary steel grades. By producing a real automotive part, thixoforging of steelswith regard to the adapted materials and to the ongoing industrial implementation of this process isproved
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/22/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.116-117.712.pdf
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