(广东工业大学 材料与能源学院，广州 510006)
摘 要: 在轴肩倾角分别为0°、1°、2°、3°、4°的条件下，对6082-T4铝合金板材进行摩擦搅拌加工(FSP)；借助光学显微镜(OM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)、电子背散射衍射技术(EBSD)等测试手段，研究了FSP轴肩倾角对板材表层晶粒和第二相形貌与分布以及晶体取向的影响规律。结果表明：所有FSP加工样品表层均呈现均匀分布的超细等轴晶及近球状第二相粒子形貌。且随轴肩倾角θ的减小，表层晶粒平均尺寸略微下降并可细化至3.10 μm，第二相粒子平均尺寸无明显变化并均可细化至0.30 μm以下，该层晶体的剪切织构E{111}〈110〉和F{111}〈112〉的强度增加。这种带有较强E、F剪切织构的超细等轴晶结构的形成与FSP加工特有的强剪切形变及动态再结晶行为相关。
关键字: 轴肩倾角；搅拌摩擦加工；铝合金板材；表层结构
（Faculty of Material and Energy, Guangdong University of Technology, Guangzhou 510006, China）
Abstract:The friction stirring processing (FSP) was performed on 6082-T4 aluminum alloy sheets at shoulder tilt angles of 0°, 1°, 2°, 3° and 4°, respectively. By means of optical microscope (OM), transmission electron microscope (TEM), X-ray diffraction (XRD) and electron backscattering diffraction (EBSD), the effects of FSP shoulder tilt angle on the morphology and distribution characteristics of grains and the second phase, as well as the crystal orientation in the plate surface were analyzed. The results show that the surface morphologies of all FSP processed samples exhibit uniform distribution of ultrafine equiaxed crystals and second-phase particles. The average surface grain size decreases slightly and can be refined to 3.10 μm with the decrease of tilt angle, while the average particle size of the second phase has no significant change and can be refined to less than 0.30 μm. and the strengths of the shear textures E and F of the layer increase. The formation of ultrafine equiaxed crystal structure with strong E and F shear texture is related to the strong shear deformation and dynamic recrystallization behavior characteristic of FSP processing.
Key words: shoulder tilt angle; friction stir process; aluminum alloy sheet; surface microstructure
