Simulation Of Aluminum Slide-rail Profile Rheological Behavior And Mathematical Model Construction In Isothermal Extrusion

Aluminum extrusion technology has become the most important method for its energy-saving, material saving and good performance of products.As Aluminum extrusion products are larger and more complex,conventional extrusion process has been difficult to meet organization and performance requirements.Isothermal extrusion technology maintains metal flow uniformity and profile outlet temperature constant throughout the whole extrusion process to obtain precise size,homogeneous performance products.And it has become an ideal way to solve the current problem.Based on hyperXtrude steady-state of orthogonal test and transient-state of billet gradient temperature simulation,it obtained optimal extrusion parameters of aluminum slide-rail profile:billet temperature 480℃, mold temperature 460℃, container temperature 430℃ and extrusion speed 4mm/s. Also,it won the best billet ladder temperature 120℃ and has realized isothermal extrusion of only 7℃ temperature difference.And the product deformation was reduced from 1.690mm to 0.054mm.By the hyperXtrude transient simulation of billet gradient temperature and verification of isothermal extrusion mathematical model, got conclusions as follow:l.The metal temperature of deformation presents stepped shape in isothermal extrusion.The temperature gets more uniform when it is closer to the die hole.But in conventional extrusion the distribution of temperature is cluttered, and it get large temperature difference.2.In deformation zone the velocity of outer metal is small,and temperature rises slowly.There are no obvious relationship between them.Center metal is in steady flow state in the tap hole.But in the weld process,the flow velocity and metal temperature of center metal synchronously increased sharply.3.The flow stress of outer metal slows down in filling and declines rapidly in welding.The flow stress of center metal is at the bottom from the tap hole 15 mm,and then rise to 30MPa rapidly.4.On the condition of 7℃ temperature difference isothermal extrusion, the slide-rail profile has uniform deformation, steady size, fine grain and uniform organization, and is consistent with the simulation results.