Comparative study of the influence of friction forces on cold forming processes in conventional ECAP die and ECAP die with low friction, by numerical simulation methods

4th ModTech International Conference - Modern Technologies in Industrial Engineering

Dragnea, D.^1 ; Lixandru, P.^1 ; Chereches, T.^1 ; Velicu, S.^2

SC UPS PILOT ARM SRL, Dragomiresti

137210, Romania^1

Polytechnic University of Bucharest, IMST Faculty, Splaiul Independentei 313, sector 6, Corp CD 003, Bucharest

060042, Romania^2

关键词: Coefficients of friction;    Cold forming process;    Comparative studies;    Effective plastic strain;    Effective stress field;    Forming technology;    Numerical simulation method;    Severe plastic deformations;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/145/2/022012/pdf
DOI  :  10.1088/1757-899X/145/2/022012

来源: IOP

【 摘 要 】

In the process of severe plastic deformation in the ECAP dies, the frictional forces between the blank and the walls of the dies play a determinant role on forming technologies. Due to the great length of the workpiece subjected to forming (in die), high frictional forces are developing, which can lead to blocking the forming process or even to the cracking of the dies. Two sets of numerical simulations were carried out for two coefficients of friction = 0.08 and = 0.10. There were analysed the following elements comparatively: the structure of the deformed mesh of the finished piece; the effective plastic strain fields; the Von Misses effective stress fields; the actuation forces on the die punch. The results of the numerical simulations showed: uniform structure of slipped layers in central areas of the finished parts, obtained by the two processes; the effective plastic strain field is uniformly at the process with low friction Von Misses effective stresses were significantly lower at the numerical simulation for the process with low friction; the application forces occurring in the processes carried out in the ECAP die with low friction are significantly lower than those obtained in conventional ECAP die.