A Study On Traditional And Continuous Equal-channel Angular Large Strain Technology By Finite Element Simulation

The technology of Sever Plastical Deformation (SPD), such as Equal-Channel Angular Pressing (ECAP) etc, has become one of the most promising methods to prepare ultra-fine grained or nanocrystalline materials. In this paper, the traditional ECAP technology, the continuous ECA technology with certain pairs of driving wheels, and the tube production technology by continuous ECA are studied using the finine element simulation software DEFORM-3D. The research content and result involeved in the present paper are listed as follows:Firstly, the traditional ECAP technology is studied. The rule of influence of friction coefficient and pressing speed on strain uniformity, strain magnitude and temperature rise were obtained. The technological parameters (friction coefficient, pressing speed) in terms of getting large strain and controlling temperature rise are established. The simulation results are in very good agreement with experiment results.Secondly, the continuous ECA technology with certain pairs of driving wheels was put forward for the first time. The dependence of temperature rise, skid phenomenon, torque distribution of driving wheels, energy consuming, and strain magnitude on technological parameters (the numbers of driving wheels, the friction coefficient between driving wheels and work piece, the channel angle of ECA dies, and the rotating speed of driving wheels) were presented. It is found that relative to merely one pairs of driving wheels, the certain paris of driving wheels is advanced in many aspects, such as reducing temperature rise, getting trid of skid, decentralizing torque, decreasing energy consuming. In addition, the advantages and disadvantage of the continuous ECA technology relative to rolling technology are also presented. These above investigation provide theoretical foundation of continuous ECA technology.Finally, the production technology of tube continuous ECA was studied. The feasibility of the technology in manufacturing tube with high strength is demonstrated. It was found that strain magnitude is very high and require more paires of driving wheels.