(廣東工業(yè)大學(xué) 材料與能源學(xué)院，廣州 510006)
摘 要: 在軸肩傾角分別為0°、1°、2°、3°、4°的條件下，對6082-T4鋁合金板材進行摩擦攪拌加工(FSP)；借助光學(xué)顯微鏡(OM)、透射電子顯微鏡(TEM)、X射線衍射儀(XRD)、電子背散射衍射技術(shù)(EBSD)等測試手段，研究了FSP軸肩傾角對板材表層晶粒和第二相形貌與分布以及晶體取向的影響規(guī)律。結(jié)果表明：所有FSP加工樣品表層均呈現(xiàn)均勻分布的超細等軸晶及近球狀第二相粒子形貌。且隨軸肩傾角θ的減小，表層晶粒平均尺寸略微下降并可細化至3.10 μm，第二相粒子平均尺寸無明顯變化并均可細化至0.30 μm以下，該層晶體的剪切織構(gòu)E{111}〈110〉和F{111}〈112〉的強度增加。這種帶有較強E、F剪切織構(gòu)的超細等軸晶結(jié)構(gòu)的形成與FSP加工特有的強剪切形變及動態(tài)再結(jié)晶行為相關(guān)。
關(guān)鍵字: 軸肩傾角；攪拌摩擦加工；鋁合金板材；表層結(jié)構(gòu)
（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
