【摘要】 采用搅拌摩擦加工技术通过加入Al₂O₃颗粒对AZ31镁舍金进行表面改性,研究了表面复合层的显微组织、力学性能及加工速度对显微组织的影响规律。结果表明:采用该技术可在合金表面成功制备出Al₂O₃/AZ31表面复合层,当搅拌头的旋转速度为1 500 r·min^-1、加工速度为23.5 mm·min^-1时,Al₂O₃颗粒均匀地分布在镁合金基体上,且与基体结合较好;Al₂O₃颗粒对再结晶晶粒的晶界起到钉扎作用,可显著细化晶粒;得到的表面复合层的显微硬度为55 HV,比母材硬度提高41%,细晶强化和颗粒强化对硬度的提高起着主要作用。更多还原

【Abstract】 Surface modification of AZ31 magnesium alloy was conducted by friction stir processing（FSP） and Al₂O₃ particles addition.The microstructure of surface composites,mechanical properties and the effect law of processing speed on the microstructure were studied.The results show that Al₂O₃/AZ31 surface composite layer could be successfully fabricated by the processing.Al₂O₃ particles were uniformly distributed in magnesium matrix and the surface composites had excellent bonding with the magnesium alloy substrate when the rotating rate was 1 500 r·min^-1 and processing speed was 23.5 mm·min^-1.The grains were refined because of the excellent pinning effect of Al₂O₃ particles.The microhardness of composite surface was 55 HV,which was increased by 41% compared with that of the AZ31 substrate.Both the grain refinement and the reinforcement increased the microhardness.更多还原