Analytical and experimental study on bonding behavior at the roll gap during complex rolling of sandwich sheets

An extended analytical model for complex rolling of sandwich sheets is proposed. Effects of various rolling conditions such as the flow stress ratio and initial thickness ratio of the raw sheets, total thickness reduction, etc., upon the bonding factors such as the bonding length, mean contact pressure, and the relative sliding distance at the interface as well as the newly generated surface ratio are analyzed. Furthermore, experiments on complex rolling of sandwich sheets are also conducted. The measured rolling force, thickness ratio of the rolled product, bonding length, and the mean contact pressure are close to the theoretical values. Through the comparisons, the validity of this proposed mathematical model is verified and the characteristics of the bonding behavior at the roll gap during complex rolling of sandwich sheets are manifested.