Optimization of structural parameters for elliptical cross-section spiral equal-channel extrusion dies based on grey theory  

作　　者：Wang Chengpeng Li Fuguo Lu Hongya Yuan Zhanwei Chen Bo 

机构地区：[1]State Key Laboratory of Solidification Processing, Northwestern Polytechnical University [2]Department of Mechanical Engineering, Tsinghua University

出　　处：《Chinese Journal of Aeronautics》2013年第1期209-216,共8页中国航空学报（英文版）

基　　金：co-supported by National Natural Science Foundation of China (No. 51275414);Aeronautical Science Foundation of China (No. 2011ZE53059);National Defense Basic Research Program (No. 51318040105);Graduate Starting Seed Fund of Northwestern Polytechnical University(No. Z2011006)

摘　　要：The elliptical cross-section spiral equal-channel extrusion （ECSEE） process is simulated by using Deform-3D finite element software. The ratio m of major-axis to minor-axis length for ellipse-cross-section, the torsion angle u, the round-ellipse cross-section transitional channel L1, the elliptical rotation cross-section transitional channel L2 and the ellipse-round cross-section transitional channel L3 are destined for the extrusion process parameters. The average effective strain eave on cross-section of blank, the deformation uniformity coefficient a and the value of maximum damage dmax are chosen to be the optimize indexes, and the virtual orthogonal experiment of L16 （45） is designed. The correlation degree of the process factors affecting eave, a and dmax is analyzed by the numerical simulation results using the weights and grey association model. The process parameters are optimized by introducing the grey situation decision theory and the ECSEE optimal combination of process parameters is obtained： u of 120 , m of 1.55, L1 of 7 mm, L2 of 10 mm, and L3 of 10 mm. Simulation and experimental results show that the material can be refined with the optimized structural parameters of die. Therefore, the optimization results are satisfactory.The elliptical cross-section spiral equal-channel extrusion （ECSEE） process is simulated by using Deform-3D finite element software. The ratio m of major-axis to minor-axis length for ellipse-cross-section, the torsion angle u, the round-ellipse cross-section transitional channel L1, the elliptical rotation cross-section transitional channel L2 and the ellipse-round cross-section transitional channel L3 are destined for the extrusion process parameters. The average effective strain eave on cross-section of blank, the deformation uniformity coefficient a and the value of maximum damage dmax are chosen to be the optimize indexes, and the virtual orthogonal experiment of L16 （45） is designed. The correlation degree of the process factors affecting eave, a and dmax is analyzed by the numerical simulation results using the weights and grey association model. The process parameters are optimized by introducing the grey situation decision theory and the ECSEE optimal combination of process parameters is obtained： u of 120 , m of 1.55, L1 of 7 mm, L2 of 10 mm, and L3 of 10 mm. Simulation and experimental results show that the material can be refined with the optimized structural parameters of die. Therefore, the optimization results are satisfactory.

关 键 词：Correlation degree Elliptical cross-section spiral equal-channel extrusion （ECSEE） Grey theory OPTIMIZATION Orthogonal design Simulation 

分 类 号：TG375.41[金属学及工艺—金属压力加工]