Effect Of Deformation And Heat Treatment On Damping And Mechanical Anisotropy Of Mg-Zn-Y Alloy With LPSO Phase

Magnesium alloy is one of the structure materials,which has the best damping capacity.In recent years,the damping capacity of it has been widely studied.But its application in industry has been greatly limited due to its poor mechanical properties and obvious mechanical anisotropy.Therefore,it is very important to study and develop a kind of magnesium alloy with good damping and mechanical properties and weak anisotropy,and to explore its basic performance control process.In this paper,the long period stacking ordered phase(LPSO phase)Mg-Zn-Y alloy with good damping and mechanical properties was studied.The damping and mechanical anisotropy were studied by alloying design,deformation process and heat treatment.Firstly,the influence of LPSO on the damping and mechanical properties of Mg-Zn-Y alloy was studied by alloying design,and the alloy with the best damping and mechanical properties was prepared,which laid the foundation of the following study.Mg-Zn-Y alloys with Y / Zn atomic ratios of 4: 3,3: 2: 1 are prepared.The three alloys are mainly composed of ?-Mg matrix and Mg12 ZnY phase(LPSO phase).Due to the moderate content of alloying elements and relatively few solid solution atoms,the Mg95Zn2Y3 alloy with Y / Zn = 3/2 has the most excellent comprehensive damping and mechanical properties.Then,four kinds of Mg-Zn-Y alloys with LPSO content of 8%,16%,32% and 64% were prepared,and their structures were observed and tested.It was found that the strength and damping of the alloy increased with the increase of LPSO content.The tensile strength of the Mg90Zn4Y6 alloy with 64% LPSO phase is 143 MPa,and the damping performance under high strain amplitude is Q-1 = 0.047.Secondly,the extrusion and rolling deformation were used to these alloys to study the effect of different deformation processes on damping and mechanical anisotropy.After extrusion,with the increase of LPSO content,the texture of alloy sheet gradually weakened,the grain gradually refined,the mechanical properties of anisotropy gradually weakened,and damping performance anisotropy gradually increased.In order to reduce the application cost,the rolling deformation was used to the extruded Mg98.75Zn0.5Y0.75 alloy(hereinafter referred to as MZY1 alloy)with lower content and lower damping performance to improve its strength.It is found that the alloy has the highest strength and better damping when the rolling pressure is 20%,and its damping and mechanical anisotropy are centering,which has great research and application value.Finally,the effect of heat treatment on damping and mechanical anisotropy of the alloy was studied by heat treatment of extruded MZY1 alloy and rolling 20% MZY1 alloy,and the optimum process of controlling alloy damping and mechanical anisotropy was obtained.It was found that the alloys in both states had good comprehensive properties after heat treatment at 500?x2h.The UTS of the extruded MZY1 alloy after heat treatment is between 261 MPa and 281 MPa,the YS is between 110 MPa and 152 MPa,and the EL is between 17.7% and 23.9%.The low strain damping is between 0.0019 and 0.0032,and the high strain damping is between 0.012 and 0.026.The UTS is between 307 MPa and 328 MPa,and the YS is between 169 MPa and 221 MPa,and the EL is between 17.7% and 21.2% after heat treatment with 20% hot MZY1 alloy.The low strain is between 0.0024 and 0.0033,and the high strain is between 0.022 and 0.045.The alloys of the two states,while maintaining high damping and mechanical properties,have greatly improved plasticity,greatly reduced damping and mechanical anisotropy,and are excellent alloys with excellent properties.