Effect of T6 heat treatment on microstructure and mechanical properties of multi-directionally forged VWZ113K rare earth Mg alloy
Taking the multi-directional forged(MDF)Mg-11Gd-3.6Y-2Zn-0.6Zr rare earth Mg alloy as the research object,the influ-ence of T5 and T6 heat treatment processes on the microstructure and mechanical properties of the multi-directionally forged rare earth Mg alloy was analyzed using scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),electron backscatter diffraction(EBSD)and tensile experiment at room temperature.The results show that the alloy after T5 heat treatment has mix crystal microstruc-ture,with large-sized long period stacked ordered(LPSO)structure strengthening phases distributed at grain boundaries.The yield strength,tensile strength and elongation of the alloy are 241 MPa,357 MPa and 13.0%,respectively.During T6 heat treatment,as the solid solution temperature increases,static recrystallization gradually nucleates and grows,promoting the improvement of microstructure u-niformity.However,grain growth can consume dislocations and reduce dislocation strengthening effects.At the same time,heating accel-erates the dissolution of LPSO structure strengthening phase,and the LPSO structure strengthening phases at grain boundaries become fi-ner and more dispersed,promoting the dispersion strengthening effect.In addition,the increase of solid solution temperature can lead to preferential grain growth and promote texture strengthening.430℃,8 h+225℃,16 h is the best heat treatment process,and the yield strength,tensile strength and elongation can reach 302 MPa,398 MPa and 11.5%,respectively.The balancing effect of various strength-ening mechanisms promotes the synergistic enhancement of strength and plasticity of alloy.
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维普
