采用搅拌摩擦加工技术对2mm厚Al-Mg-Si(6061-T6)合金板材进行加工.研究了具有相同速度比的搅拌摩擦加工对搅拌区微观组织演变、显微硬度分布、拉伸性能和腐蚀行为的影响.结果表明,加工区微观组织如晶粒形貌、平均晶粒尺寸、晶界分布和析出相演变特征具有明显差异,进而对力学性能和腐蚀行为产生显著影响.加工区等轴再结晶晶粒平均尺寸随着加工速度增加而逐渐减小.转速8000r/min和加工速度800mm/min工艺下制备的加工区平均晶粒明显细化,析出相分布也更加接近于母材分布特征.最终,该加工区除了耐腐蚀性能轻微改变之外,展现出了较优的力学性能.加工区最大抗拉强度和延伸率分别达281.5 MPa和34.8％,分别为母材的86.3％和122.1％.高速搅拌摩擦加工对腐蚀性能改善不明显,但可有效改善Al-Mg-Si合金的力学性能.“,”Friction stir processing(FSP)was applied to process a 2 mm thick Al-Mg-Si(6061-T6)alloy plate.The influence of the FSP with the same speed ratio on microstructure evolution,microhardness distribution,tensile properties and corrosion performances of the stirred zone(SZ)in the 6061-T6 alloy was investigated.Results show that there are obvious differences in the microstructure,such as grain morphologies,mean grain size,grain boundary distributions and precipitate distributions of the SZ prepared using the FSP with different processing speeds,which in turn affects the mechanical properties and corrosion resistance.The mean grain size of the equiaxed recrystallized grains of the SZ sample prepared by high speed(8000 r/min,800 mm/min)is 9.5 μm,which is significantly refined compared to 23.2 μm of the conventional speed(1000 r/min,100 mm/min)and 13.6 μm of the as-received 6061-T6 alloy.In addition,the distribution characteristics of the precipitates are more similar to that of the as-received 6061-T6 alloy.As a result,in addition to the slight change in corrosion resistance,the SZ sample prepared using the high speed FSP exhibits excellent mechanical properties.The maximum tensile strength and elongation of the SZ sample are 281.5 MPa and 34.8％,which are 86.3％and 122.1％of that of the as-received 6061-T6 alloy,respectively.