Optimum processing parameters for equal channel angular pressing

• In this study, we find the optimum processing parameters for maximum strain homogeneity in ECAP based on the analysis of steady zone.
• Among all the combinations of 252 study cases; we presented the selected optimum parameters for minimum strain coefficient of variance.
• We reported that acute and right channel angles are preferred in ECAP.
• Smaller corner angles maximize the homogeneous portion of the billet.
• The influence of friction coefficient on punch load is more pronounced than the influence of die geometry.

This study aims to explore the optimum processing parameters for minimum strain coefficient of variance in equal channel angular pressing based on the analysis of whole steady zone. In order to design the die correctly, it is important to understand the effect of die geometry and processing parameters on the deformation behavior, strain distribution and punch load. The influences of channel angle, corner angle and friction coefficient are analyzed using finite element modeling. Analytical models are also used to validate the obtained computational solutions. Results showed that channel angle, corner angle and friction coefficient have significant influences on deformation behavior, strain coefficient of variance and punch load evolution. Among all the combinations of 7 corner angles, 6 channel angles and 6 friction coefficients (set of 252 study cases), it is found that the optimum parameters for maximum strain homogeneity correspond to channel angle ϕ=90o,ϕ=90o, corner angle ψ=15oψ=15o and friction coefficient μ=0.3μ=0.3. The influence of friction coefficient on punch load is more pronounced than the influence of die geometry.