Numerical Analysis of Process strain rate in Cyclic Extrusion Compression inEqual Channel Angular Pressing (CECAP) by FEM and RSM Methods for CPTi

To examine the effects of the process and geometrical input parameters involved in Cyclic ExtrusionCompression in Equal Channel Angular Pressing (CECAP) on the respond variables, Respond SurfaceMethodology (RSM) and Finite Element Analysis (FEA) were performed. Friction coefficient (𝜇), ram speed(V), longitude distance of input extrusion to ECAP region (L) and input extrusion diameter (D) wereconsidered as input parameters to study strain rate (𝜀̇) on simulated sample using standard deviation (S.D.)formulation as a response. Since CECAP is carried out at higher temperatures and consequently, temperatureactivatedevolutions such as dynamic recrystallization are appeared in the samples, thus, the control of thestrain rate and its distribution on sample are of great importance. Due to the medical purposes of CP-Ti, it wasselected as material to be inspected. RSM and Analysis of Variance (ANOVA) were employed tomathematically develop the model for the respond and determine the significant parameters, respectively.Design Expert and Deform ۳-D software’s were applied to run the RSM experiment set and numericallyperform the process, respectively. Finally, ANOVA results showed that ram speed and interaction of inputextrusion diameter and friction coefficient are significant parameters influencing standard deviation (S.D),followed by the longitude distance of input extrusion to ECAP region which is not considered as an effectivefactor in this analysis

Keywords:

strain rate , CECAP process , Respond surface Method , Finite Element Analysis , CP-Ti