A Study On Isothermal Extrusion Of Aluminium Rod

In conventional studies on the Aluminium extrusion process, extrusion technics is often determined by experiment. At present, with the development of computer technology, CAD/CAM/CAE are widely introduced into the manufacturing industry and researchers tend to use numerical simulation method to study the extrusion technics.During conventional hot extrusion processes, temperature and distortion of the billets change unevenly, so the dimension, shape, organization and capability of the profile will be deterioration. With the development and study of the extrusion technology, people gradually realize that isothermal extrusion technology will eliminate these quality limitations. There are many ways to realize isothermal extrusion. In this paper, isothermal extrusion which used variable speeds is studied. But the researches mainly focus on those relatively simple-shaped workpieces due to the complexity of aluminium extrusion process.In this paper, the author founded a model which consider of heat conduction, convection, and heat generation due to plastic work and friction. Using the rigid-plastic finite-element method and plane axisymmetric element, the model is capable of simulating the hot extrusion with constant and variable speeds. The temperature distribution and the speed effects in hot extrusion are predicted in detail by the proposed numerical model. The results show that reasonable speed criterion will realize approximately isothermal extrusion.The research proves that the results of the numerical simulation could optimize the parameters of the extrusion technics, sequentially the productivity will be improved greatly. The proposed numerical simulation has been demonstrated to be a powerful tool for the design of hot extrusion processes.