1. Introduction

Because of the need for weight reduction in the transport industry, the use of aluminum is taken increasingly into consideration [RWT 98]. But although aluminum is lighter than steel, the formability is less, hence press operations are often more critical. Press operations can be improved by optimizing the mechanical properties of the sheet by local heating or cooling [SHE 78, WIL 88, SCH 95a, SCH 95b, BOL 00, BOL 01]. An extra benefit of warm forming is that the stretcher lines that occur when 5xxx alloys are deformed at room temperature do not appear at elevated temperatures.

In deep drawing of an AA 5754-O aluminum cylindrical cup, the limiting drawing ratio could be increased from 2.1 to 2.6 by heating the flange up to 250 C and by cooling the punch at room temperature as demonstrated in an experiment performed by the authors (see Figure 1). In this paper experiments with the AA 5754-O alloy are analyzed, to determine whether a numerical analysis can predict the punch force-displacement curves and the thickness distribution of the final product. Uniaxial tensile tests were performed at 4 different temperatures and at 2 strain rates. With the data from these experiments, the parameters for two material models were fitted. Finally, the cylindrical deep drawing experiments were simulated using these models. The results are presented in Section...