【摘要】 研究了在150和300℃温度下采用顺轧、交叉轧2种方式制备的4种AZ31镁合金轧制板材的显微组织、织构和单轴拉伸力学性能.研究表明:{1011}{1012}双孪晶是镁合金板轧制变形过程中的重要变形机制.变形温度的升高会抑制{1011}{1012}双孪晶的产生.轧制过程中,{1011}-{1012}双孪晶的变体选择机制与轧制方向有关,进而对轧制板材的显微组织、织构及力学性能产生不同的影响.低温顺轧将使板材中的双孪晶平行排列,板材的织构各向异性、单轴拉伸塑性各向异性增强;而低温交叉轧将使板材中的孪晶分布杂乱.织构各向异性、单轴拉伸塑性各向异性均较顺轧板材减弱.高温轧制板材中双孪晶较少,板材的织构各向异性和拉伸各向异性均较弱.更多还原

【Abstract】 {1011}—{1012} double twin is the most common twin type being observed in the rolled AZ31 magnesium alloy,especially at low or moderate rolling temperature.Four types of rolled AZ31 magnesium alloy sheets were produced by rolling strong basal textured AZ31 plates at 150℃and 300℃respectively through different rolling paths by two passes till total reduction 17%. The rolling paths are normal and cross rolling respectively:the rolling directions of the two passes for normal rolling are mentally paralleled while perpendicular to each other for the cross rolling.Sheets are characterized in terms of microstructure and texture using optical microscope and scanning-electron microscope equipped with EBSD detector,and their mechanical performances are measured by uniaxial tensile tests at room temperature and a strain rate of 0.001 s^-1.Tensile samples are cut parallel or perpendicular to the final rolling direction to obtain the mechanical anisotropics.The effects of the {1011} {1012} double twins occurred during rolling on the microstructure.texture and mechanical properties of the rolled sheets are discussed and related to each other.The results show that the fraction of {1011}-{1012} double twins varies widely in different rolled sheets,which are determined by the rolling temperature.The twins in different rolled sheets are arranged in different ways.In the normal rolled sheets,the traces of twins are approximately perpendicular to the final rolling direction,while in the cross rolled sheets there are both traces of twins parallel and to the final directions.This phenomenon is related to the variant selection of twinning during rolling deformation. And the variant selection law is related to the rolling direction.For the same reason,the textures of twins in the rolled sheets produced through different paths are different.The textures of twins will add onto the bulks,and increases the textural difference between the bulks.The differences between mechanical properties of the rolled sheets are also related to the different textures and microstructures of the sheets caused by twins.更多还原