A Friction Evaluation Method Based on Barrel Compression Test

To further understand the tribological performance in metal forming, it is critical to accurately evaluate the friction between tool and workpiece. However, the unclear contact conditions at the interfaces and the complex mechanisms of the tribology lead to challenges to assess friction in metal forming processes. In this study, a friction evaluation method by the barrel compression test and its principle model were proposed based on the theoretical analysis and the numerical simulations. Besides the friction factor at the die-specimen interfaces and the initial aspect ratio of the specimen, the strain hardening exponent of the specimen was found to affect the barreling profiles based on the theoretical analysis. Furthermore, the effects of the three influencing factors, including the friction factor at the interfaces, the initial aspect ratio and the strain hardening exponent of the specimen, on the defined barreling factor were numerically analyzed by the finite element method. A predictive model of the barreling factor accounting for these three factors was developed. A friction evaluation method, proposed based on this model, was implemented by various cylinder compression experiments of CuZn40 brass. The method proposed in this study provided a convenient means to identify the contact friction in metal forming processes.