Analysis of Strain Inhomogeneity in Vortex Extrusion using Finite Element Method and Response Surface Methodology

The effect of geometrical parameters involved in vortex extrusion (VE) die design, on AA1050 aluminium alloy processed by VE were investigated using finite element analysis (FEA) and response surface methodology (RSM). For this, VE die length (L), reduction in area (RA), twist angle (𝜑), and position of control points in Beziers formulation (C1) were considered as input parameters and strain inhomogeneity was considered as a response. Both standard deviation (S.D) and inhomogeneity index (Ci) were used to quantify the strain inhomogeneity from FEA results. Analysis of variance (ANOVA) was used to determine the significant parameters and to mathematically model the strain inhomogeneity. It was concluded that standard deviation (S.D) is not a good choice for examining the strain inhomogeneity distribution in VE technique. ANOVA results showed that 𝜑, RA, and interaction between 𝜑 and RA are the most significant parameters affecting the strain inhomogeneity.