Effect Of Heat Treatment On Damping Performance Of Deformed AZ80+0.4%Ce Magnesium Alloys

Damping materials can transform the vibration energy into thermal energy and dissipate it by the viscoelasticity of materials,thus reducing the structural vibration.Dynamic mechanical analyzer?DMA?was employed to investigate damping capacities of different heat treated AZ80+0.4%Ce alloys,which was taken from hub plate.The heat treatment scheme of alloys was designed by Box-Behnken experiment method.The effect of different heat treatment on the damping capacities of alloys was analyzed.Microstructure of alloys was studied by optical microscopy?OM?and scanning electron microscope?SU-5000?,and then the microscopic mechanism of damping performance of AZ80+0.4%Ce magnesium alloy was analyzed.At first,the process parameters of heat treatment process in Box-Behnken experiment design method were confirmed by studying the effects of the solutions system and the aging system on the damping properties of alloys,and the regression equations of tensile strength and damping coefficient were completed.The results showed that aging temperature and aging time were respectively main influence factors of tensile strength and damping coefficient.The best parameters of heat treatment process of the alloys were 410?for 2.5h and 193?for 17.5h.The corresponding value of maximum responses were as following:the tensile strength reached 266.72 MPa and the damping coefficient reached 0.176.Then,the effects of aging parameter and the solution parameter on damping capacities of alloys were analyzed separately.The results showed that under different aging systems,when the number of precipitated phases in AZ80+0.4%Ce magnesium alloy is large,the larger the precipitation area fraction,the worse the damping performance.However,different solution systems had little effect on the damping properties of alloys under the same aging system.In the solution process,the Al₁₁Ce₃ phase in the alloy can inhibit the growth of the alloy grains and the changes of solution temperature and time did not affect the grain size of the alloy.The Q₀^-1values of the alloy in the region of strain-amplitude independent damping were all around0.015.Solution treatment had little effect on the number of Al atoms in AZ80+0.4%Ce magnesium alloy and the damping properties of alloys.Finally,based on the best heat treatment parameters,a verification experiment was designed.The actual tensile strength under room temperature reaches 271.4MPa and damping coefficient reached 0.245.The rod-shaped Al₁₁Ce₃ phase and strip?phases formed on the surface of grains after solution-aging treatment can improve the damping properties of the alloy.However,the surrounding of the strip?phases is usually accompanied by needle-like and punctiform?phases,and Al₁₁Ce₃ phases and?phases are both used as strong pinning points in AZ80+0.4%Ce magnesium alloy.The alloys with too much?phases will hinder dislocation movement and reduce damping capacities of the alloys.