Mg合金中(11(2)1)孪晶的形成条件OA

Twinning is a critical deformation mechanism in hexagonal close-packed(HCP)metals,playing a pivotal role in plasticity.Understanding the factors that govern twinning behavior is essential for the design of high-strength,tough Mg alloys.In this study,typical Mg-xGd(x=4％,8％,12％,16％,20％,mass fraction)binary alloys have been used as model alloys.Electron backscatter diffraction(EBSD)has been used to systematically investigate the twinning deformation behavior during room temperature compression.The findings demonstrate that when the mass fraction of Gd is less than 12％,the dominant twinning mode is(10(1)2)twinning.As the Gd content increases,a gradual transition to(11(2)1)twinning occurs.Notably,upon reaching a Gd content(mass fraction,the same below)of 16％,(11(2)1)twinning first appears and becomes more prevalent with increasing Gd concentrations.The content of rare earth element Gd is the decisive factor in the formation of(11(2)1)twins under room-temperature conditions.(11(2)1)twins could only form when the amount of Gd added reaches a certain value.The research results also show that the higher the amount of Gd added,the greater the compression strain,the higher the compression rate,and the easier it is for(11(2)1)twins to form.