An advanced forming process involving hot forming and cold-die quenching, also known
as HFQ®, has been employed to form AA6082 tailor welded blanks (TWBs). The HFQ® process
combines both forming and heat treatment in a single operation, whereby upon heating the TWB, it
is stamped and held between cold tools to quench the component to room temperature. The material
therefore undergoes temperature, strain rate or strain path changes during the operation. In this
paper, a finite element model (FEM) was developed to investigate the formability and deformation
characteristics of the TWBs under HFQ® conditions. Experimental results, i.e. strain distribution,
were used to compare and validate the simulation results. A good agreement between the
experiment and simulation has been achieved. The developed temperature, strain rate and strain
path dependent forming limit prediction model has been implemented into FE simulation to capture
the complicated failure features of the HFQ® formed TWBs. It is found from both experiment and
simulation that the forming speed has important effects on the occurrence of failure position, where
the failure mode for the 1.5-2 mm TWBs may change from localised circumferential necking to
parallel weld necking.
HFQ® is a registered trademark of Impression Technologies Ltd.