Modelling and Experimental Investgations of Tooling Issues for Thixoforming of Steel

摘要

Since the early 90's, and from the very early investigations of steel thixoforming, tool materials as well as different kinds of coatings, including different tool steels and fully ceramic systems have been evaluated. The failure mechanisms have been carefully investigated by experiments and simulations and are nearly fully understood. Analysis of the reported literature on this topic shows that there is still a lot to do in this field and no excellent solution exists now a days for steel thixoforming. The aim of this work is to evaluate the thermal and mechanical loadings applied to the tools during steel thixoforming process in order to determine appropriate tool materials and solutions. This evaluation was realized thanks to experimental trials and to the finite elements simulations. The effect of these loadings on the tool's failure modes are highlighted and compared to the ones observed in classical forming processes. Beyond this, the failure modes of different tool materials and solutions are presented. The tested materials are hot-working tool steels. Other possibilities and tool coating or surface treatments are discussed as well.