Large Tapered Cylindrical Member Magnesium Alloy Extrusion Effort Scheme

As the most lightweight structure material, magnesium alloys are widely used inmilitary and aerospace equipment which is one of the important ways to achieve thegoal of equipment mitigation. However, the mechanical properties of magnesiumalloys are worse compared with usual high-strength heat-resistant aluminum alloys,especially in terms of toughness and heat resistance, which is difficult to meet thestandard of military and aerospace-grade materials. Adding rare earth is an effectiveway to strengthen the performance of magnesium alloys. Compared with ordinarymagnesium alloys, the mechanical properties at room temperature of magnesiumalloys with rare earth have been greatly improved. However, the plastic deformationis the most effective way to strengthen magnesium alloys.Mg-13Gd-4Y-2Zn-0.6Zr is a new type of high-strength heat-resistant magnesiumalloy material with superior mechanical properties and strong creep resistance whichcan achieve the performance requirement of the materials in military and space filed.However, with regard to the strengthening mechanism of plastic deformation of thesematerials, domestic research is still not deep enough. In this paper, thermaldeformation mechanical behavior research was carried out by establishing constitutiveequations and thermal processing diagrams, which were based on the thermalsimulation experiment of Mg-13Gd-4Y-2Zn-0.6Zr alloys.Large-scale magnesium alloy tapered cylinder components are one of the partscommonly used in military and aerospace systems for its advantage of good flowdynamic. But its forming is difficult, mainly due to the following two reasons: thepoor plasticity of magnesium alloy itself which increases the difficulty of its forming;large forming force is need during its forming which increases the requirements for the mold and the press.Importing the constitutive equation of Mg-13Gd-4Y-2Zn-0.6Zr alloy into thesoftware of DEFORM to simulate the forming process of large-scale magnesium alloytapered cylinder component. The load-displacement curve was used to study the metalflowing law during the forming and a labor-saving extrusion method was got byimproving the forming technology. Combining the processing map ofMg-13Gd-4Y-2Zn-0.6Zr alloy, the parameters such as deformation temperature anddeformation rate were determined in the extrusion process. Experimentation validatedthe labor-saving extrusion method, large-scale magnesium alloy tapered cylindercomponents with suitable size and required performance were obtained, which provedthe method is reasonable.