Numerical Simulation And Parameter Optimization Of Tube Extrusion Process For Mg-3Sn-0.5Mn Alloy

In this paper, numerical simulation and parameter optimization of tube extrusion processwere researched for Mg-3Sn-0.5Mn alloy. The extrusion process was studied by the finiteelement software Deform-3D, and the purpose was to preparate a new biodegradablethin-walled tubes stent made of the Mg-3Sn-0.5Mn alloy.Firstly, sothermal compression test for the Mg-3Sn-0.5Mn alloy was conducted at250°C-450°C, strain rate of0.001s-1-10s-1on Gleebal-1500D thermal simulator, the results showedthe stress-strain curves exhibited the characteristics of dynamic recrystallization, and theconstitutive equation of Mg-3Sn-0.5Mn alloy applied to warm forming was established basedon the Arrhenius formula, the simulation results agreed well with experimental datas, whichproved the accuracy and usability of the equation.Secondly, extrusion process parameters for the Mg-3Sn-0.5Mn magnesium alloy rodswere optimized, the results showed that extrusion ratio played an important role in extrusionprocess. The combined properties of the magnesium alloy rods at the extrusion ratio of20were best.Finite element software Deform-3D was used to simulate the extrusion process, theinfluence factors were tested by investigating stress, strain, temperatures and load step, theextrusion die was designed based on simulation results, then extrusion tools and equipmentswere designed and produced. The heat deformation temperature and effective stress bydeformed material Mg-3Sn-0.5Mn alloy through different extrusion ratios were discussed,meanwhile, the best extrusion ratio were confirmed. Numerical simulation methods were usedto simulate extrusion process parameters, then the extrusion temperature and speed wareidentified. Extrusion experiment was carried out following the simulation results, according tothe results, the microstructure and tensile mechanical properties of the extrusion rods wereproved the accuracy of the simulation. The results obtained frorm the extrusion exprimentsshowed that the as-extruded Mg-3Sn-0.5Mn alloy grains had greatly refined compared to theas-cast alloy, and tensile strength increased from162MPa to251MPa.Finally, the thin-walled tube extrusion methods were discussed. The Mg-3Sn-0.5Mn alloytube extrusion die was designed by using finite element techniques. The temperature, gap and needle length which would affected the tube extrusion process were analyzed, furthermore,the optimum extrusion parameters were determined by extrusion deformation numericalsimulation, and the results would be used to guide subsequent extrusion experiments.