The CONFORM continuous extrusion process provides outstanding features and the process has been widely used in non-ferrous metal production since it was invented. Although research and development has been quite extensive, theoretical analysis of the process has been based purely on the finite-element method, which is unable to give suitable analytical equations for calculating the stress distribution. Theoretical expressions for the contact stress distribution between the deforming material and the tools are derived in this article for the specific purpose of evaluating the load and power requirements of the machine. A simplified five sub-zone model is first established according to the different deformation characteristics in the different regions of the machine. Subsequently theoretical solutions are obtained based on simplified plasticity analysis and finally expressions are derived that can be used for calculating the load acting on the extrusion wheel and shoe. In addition, experimental verification of the theoretical results is reported.Also, much research has been carried out to investigate the process as outlined below.Cho and Jeong [5, 6] simulated the effects of the wheel diameter on the surface separation and curling phenomena as well as other significant process characteristics using the two-dimensional (2D) and three-dimensional (3D) finite-element method (FEM) for solid section aluminium products. Lu et al. [7] carried out 2D FEM simulations to determine the stress, strain, strain rate, and temperature fields for processing AA6061 aluminium alloy. Lee et al.[8] describe a 3D FEM simulation of a porthole die CONFORM extrusion process for producing aluminium multi-port-tubes used for automobile cooling systems. Reinikainen et al. [9] carried out 2D FEM simulations for CON-FORM extrusion of copper, which was assumed to take place under plane strain and isothermal conditions. Kim et al. [10] predicted the extrusion load and torque for CONFORM processing using the upper bound method.In industrial applications, there is great deal of concern regarding how to select the appropriate type and specification of a CONFORM machine in order to JPME210

Continuous extrusion expansion deforming is an advanced forming process for manufacturing copper bus-bar, die and tool structure is important effect factor of deformation. Based on the characteristics of the forming process, the model of rigid-plastic finite element (FE) on DEFORMT is established and the numerical simulation of continuous extrusion expansion forming process of the copper bus-bar is carried, The metal flow regularity and the mean-square deviation of velocity (SDV) with the different structure of expansion chamber and port hole and die assembled pattern is analyzed. The result show that when using the drum expansion chamber, the trapezium of port hole without transition surface and the die fitted in reverse, the variance of flow velocity is the minimum and deformation is the most homgeneous, the SDV is 0.62. The simulation results provide a theoretical direction for optimization design of die and tool structure of the continuous extrusion expansion forming. Keywords: copper bus-bar, continuous extrusion expansion deforming, die and tool structure optimization, numerical simulation

This paper present exploration of polymer extrusion under melted temperature by conform process. The stress distribution of the process is described based on plastic mechanics. Solutions are presented and detailed comparisons are made between theoretical predictions and simulation results.

Engineering plastics has many uses, such as national defence, communication and scientific research. In this paper a new experiment plan was proposed in order to get a new engineering plastics forming method. Through the compressive test of polyoxymethylene powder, the process parameters such as temperature, stress and velocity are obtained.Based on the parameters got from compressive test polyoxymethylene powder solid extrusion forming was studied by self-made device. Microscopic analysis and mechanical properties test show that the process parameters are reasonable, the crystallinity increase and molecular chain is oriented along the extrusion direction, as a result the tensile strength and modulus increase greatly.