Hot deformation behavior,microstructure and texture evolution of extruded Mg-0.5Bi-0.5Sn-0.5Ag alloy
A novel Mg-0.5Bi-0.5Sn-0.5Ag alloy(BTQ000 alloy)was developed and fabricated through extrusion.Hot compression experiments of BTQ000 alloy were carried out at a deformation temperature of 400℃and a strain rate of 10 s-1.The deformation mechanism,microstructure and texture evolution of the alloy at different strain stages were studied.The results show that the flow stress profile of BTQ000 alloy can be divided into four stages:work hardening,dynamic recovery,steady state and extra strain hardening.The alloy has obvious recovery and dynamic recrystallization.With the increase of strain,the average grain size first increases and then decreases,while the area fraction of twin crystals gradually declines.The area fraction of sub-grains initially increases before declining.When the strain is 0.1,the area fraction of sub-grains reaches the maximum of 76.2%.The sub-grains play a dominant role in determining the type of texture and strength,while the texture strength shows a trend of decreasing initially before increasing.When the strain is 0.4,the large number of dynamic recrystallized grains with dispersed orientation reduce the peak strength of texture,thus showing that sub-grains and dynamic recrystallisation distribution grains are the dominant factors that influence the type of texture and strength of the alloy.
Mg-Bi based alloyhot compressionmicrostructure evolutiontexturedeformation behavior
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