| Magnesium alloy is the lightest metal of structural materials in project application right now. It has many advantages as excellent electrical and heat conductivity, high specific strength and specific rigidity, mechanical machining manufacturing facility and convenient recycling. Now magnesium alloy is widely applied to electronic industry, aerospace industry, and auto industry. However, the close-packed hexagonal structure of magnesium alloy weakens its plasticity capability and hampers the deformation at ambient temperature that may hinder the further application. By using the finite-element numerical simulation technique, the analysis of the structural and the forming process about magnesium alloy in experiment have important theoretical contributions and the practical significance on studying the method of magnesium alloy grain refinement and the forming rules. It provides the significant guidance on the industrialization and practicality of magnesium alloy.Extrusion process is one of the important methods to make magnesium alloy plastic deformation. Usually magnesium alloy is dynamical recrystallizated in heat extrusion process that the grains obtain refined and the strength and plasticity are improved. With the finite-element software DEFORM-3D, we simulate the extrusion deformation process on magnesium alloy rod ZK60 and analyzes the effects of the extrusion process in materials flow velocity, stress field and hard deformation part. Then we simulate the grains microstructure evolution and dynamical recrystallization process under different parts and different extrusion ratios in the rod forming process.This paper designs the rod extrusion die and obtains the technological line and parameter in the rod extrusion process. With the optical microscopic structure inspectio in ZK 60, first and second extruded product, we analyze the microstructure changing in the plastic deformation. Through the analysis of microstructure, we study the microstructure evolution mechanism in different parts of the extruded products and the effect factors under different extrusion ratios of the rod extrusion deformation process. Then we offer solutions after finding out the reason why the extrusion parts have crack defects. This paper proves the assisted of the numerical simulation on extrusion deformation study by validating the high goodness of fit between the numerical simulation experiment results and the optics microscopic structure. |
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