| During the hot extrusion process the die plays an important role in determining the quality of the finished product. The service life of a die in the metal forming industry is limited by wear, fatigue, fracture, and plastic deformation. In high temperature metal forming processes, such as round bar hot extrusion, the principal life-limiting factor is wear. Die wear is a product of thermal loading and hot metal contact during deformation. The motivation behind this research is to extend die life productivity by minimizing the required extrusion load and in doing so the hot metal contact. Extending die life will allow for higher production rates and lower tooling costs.; In this study the extrusion load was varied by controlling the extrusion die profile. The profile of the extrusion die was defined by five variables: inlet radius (R1), outlet radius (R2), orifice angle (alpha), upper blend radius (Ra), and lower blend radius (Rb). From these 5 variables 50 different die profiles were generated and extrusion loads were simulated using 2D axisymmetric geometry in DEFORM manufacturing finite element software. A regression analysis was performed on the results to construct a relationship between the die profile variables and the extrusion load in the form of a transfer function.; The transfer function developed in this study can be used to minimize extrusion load through optimizing the die profile. By fixing the values for R1 and R2 the die profile can be optimized through the remaining terms alpha, Ra, and Rb. In order to extend the die service life future work would include an experiment comparing the life before and after the die profile was optimized. An assessment of these lives would determine whether or not minimizing the extrusion load extends die service life. |
