determination of flow stress and friction factor of aluminum 7075 by inverse analysis

in all engineering applications where solid surfaces slide on each other, friction plays an important role. it becomes even more important, particularly in metal forming processes where the two sliding materials are metallic. among forming processes, forging is an important process, because of improving material structure, mechanical properties and reducing production time. an inverse analysis technique has been developed to determine the flow stress and friction at the tool/work piece interface simultaneously. the inverse problem is aimed at minimizing the error between experimental data and predictions made by rigid-plastic simulations. the ring compression test was selected for evaluating the method for bulk forming of aluminum7075. the determined friction data were compared with corresponding data obtained independently using standard calibration curves for cold forging in the ring compression test. results show that the method discussed in the study is efficient and accurate.