Microstructure And Properties Of Mg-Zn-Zr Alloys Subjected To Cyclic Extrusion And Compression Base On The RE Microalloying

Due to its special properties such as light weight and high strength,electromagnetic shielding and seismic resistance,the deformed magnesium alloy is a promising lightweight structural material.Due to its typical hexagonal close-packed structure,the magnesium alloy can easily introduce a strong {0002} base after plastic working Texture,resulting in magnesium extrusion along the extrusion direction for the performance of a serious lack of compressive strength,making the pure magnesium alloy tensile properties based on the design of components to bring security risks,especially in the alternating load,multi-directional load and other complex loads Especially severe,restricting the application of deformed magnesium alloy in the field of structural load and structural weight loss.In this paper,based on the previous research,based on the commercial ZK60(Mg-Zn-Zr)magnesium alloy as the experimental object,through the micro-alloying of rare earth elements such as Y and Gd,the microstructure is refined and the strength of the magnesium alloy is improved.The effects of conventional extrusion and reciprocating extrusion on the microstructure and mechanical properties of Mg-Zn-Zr-x RE alloy before and after plastic deformation were analyzed.The results show that RE has obvious grain refinement effect on the extruded ZK60 magnesium alloy,And reached the minimum of 5.2μm at 1.81 wt.%Y.At the same time,it was also beneficial to the weakened effect of the extruded base textures.The I phase formed after addition was a significant reinforcing phase,while the W-phase was not conducive to the performance improvement,and then a comprehensive analysis to establish the texture Under the action of the fine grain strengthening,precipitation strengthening and other strengthening mechanism composite magnesium alloy toughening design mode,to achieve complex conditions of service of high tensile/compression deformation of magnesium alloy preparation,of which 1.5wt.% Y The most excellent overall performance is obtained with a tensile yield strength of 219 MPa,a compressive yield strength of 245 MPa,a TYS / CYS of about 0.9,and good room temperature ductility.This provides important data reference and technical guidance for the design and processing of high-strength magnesium alloy materials.