Process Testing And Numerical Simulation Of AZ31 Magnesium Alloy Continuous Extrusion

Continuous extrusion is a special kind of deformation. It is the method that uses the friction force, which between extrusion wheel and metal to cause the material have plastic deformation. Its particularity lies in the fact that this is a multi-deformation process in one process. This kind of complex distortion pattern is advantageous in refining grain, enhancing the overall properties, thus obtains the wire rod products with excellent performance.This article innovatively produce AZ31 magnesium alloy wire by using continuous extrusion, discusses its feasibility. Study the process parameters on product performance of organizations through experiments and numerical simulation technology. Explore the characteristic of AZ31 magnesium alloy by continuous extrusion, provides the reference data for production technology and dies designing. It is expected to provide a new method of processing AZ31magnesium alloy wire.Continuous extrusion of as-cast AZ31 magnesium alloy carries on 250 Continuous Extrusion Machinery. Microstructure changes in deformation area are analyzed, as well as the influence of extrusion speed and extrusion ratio on microstructures and mechanical properties. Finite element model of continuous extrusion process is established by DEFORM software. Numerical simulation carries on different technological conditions, such as temperatures of cavity and raw material and run speed. The changes of temperature, effective stress and effective strain are analyzed on these technological conditions. The results showed that:Continuous extrusion can be used to AZ31 magnesium alloy wire forming. The thick Cast structure is distorted directly into tiny equiaxed grain organization. The degree of grain refinement has relation with extrusion ratio. When extrusion ratio increased, the grain size decreased, the uniformity of grain increased. The grain size can achieve 2μm. When extrusion speed increased, the uniformity of grain size increased. High speed can make the distortion temperature increase, so that soften and uniform the organization.In compaction area, the maximum temperature of the metal is increased with initial temperature. Cavity's initial temperature and extrusion speed are not obviously influenced. In curving extrusion area, the maximum temperature of the metal is increased with the extrusion speed increased. When initial temperature of the cavity is 300℃, the maximum temperature occurred near the block,. When initial temperature of the cavity is 20℃, the maximum temperature occurred at the entrance of the die, the largest effective stress and effective strain occurred both in the area above the metal adhesion and entrance of the die.