Bearing Design Simulation in Direct Extrusion of AA2024 Using Finite Element

摘要

Extrusion is a metal forming process which involves plastic deformations. Economic significance of extrusion is due to its material efficiency, labor costs reduction, elimination of intermediate treatments, better output quality, and high production rates. Bearing length is one of the important features in extrusion dies. The aim is to make all the material points in outgoing profile have the same flow velocity, so in an effective design the flow velocity of thick features is controlled to be same as for thinner features. AA2024 alloy is widely used in military and aerospace industries. It has a high heat treatment capacity and strength to weight ratio. Other characteristics include excellent toughness, fatigue behavior, crack growth resistance, and machinability. However it is difficult to extrude. The purpose of this paper is to determine a strategy for designing bearings in direct extrusion dies which are used in production of parts from AA2024 aluminum alloy. Proper design of bearings is among factors of controlling material flow in this process and has an important role in scrap rate reduction. Using ABAQUS finite element software package, direct extrusion process is simulated. Results are explored and investigated for different conditions and finally, an efficient bearing configuration is introduced. Finally, it is shown that using uniform bearing for complicated sections is not possible. Optimum design is also presented using finite element analysis.