反复镦压6013型铝合金的组织和性能

Microstructure and Properties of 6013 Type Aluminum Alloy Produced by Cyclic Channel Die Compression Process

以6013型铝合金为试验对象,研究了反复镦压工艺制备细晶材料,消除合金各向异性的可行性。采用金相显微镜,透射电镜研究了6013型铝合金反复镦压对合金组织和性能的影响。结果表明:反复镦压使合金内部产生取向各异、彼此交错的变形带,有利于细化合金组织,经480℃,2 h的退火处理后,合金发生再结晶,合金晶粒等轴化,大小分布均匀,与未反复镦压合金组织相比,晶粒显著细化,减轻了组织各向异性;合金强度随镦压道次的增加,先降低后升高,对镦压后的合金进行T6处理(560℃,2 h+191℃,4 h),反复镦压3道次和12道次合金的硬度分别为1418.5和1503.5 MPa。研究表明:反复镦压工艺可以有效细化晶粒,消除组织各向异性,多道次镦压后,合金强度有所提高。

6013 type aluminum alloy produced by cyclic channel die compression （CCDC） process was investigated to explore whether the fine grain and elimination of anisotropy can be obtained. Microstructures and properties of 6013 type aluminum alloy were tested by optical microscopy （OM）, transmission electron microscopy （TEM） and hardness tester. The results indicate that CCDC process can effectively refine the grains and eliminate the anisotropy. Different-orientation, staggered belts are observed, which is conducive to refining the microstrueture when the alloy is subjected to CCDC process. Recrystallization, equiaxed grains, and homogeneous distribution are gotten when the alloy is annealed at 480 ℃for 2 h. The grains are significantly refined and the microstructural anisotropy is reduced compared with the alloy without CCDC. The strength of the alloy decreases first and then increases with increasing the passes of CCDC. The hardness （HV） of the alloy is 1418.5 MPa and 1503.5 MPa compressed by 3 passes and 12 passes, respectively, when the alloy was treated by T6 solution-aging （560 ℃/2 h＋191 ℃/4 h）. It is shown that the fine grain and elimination of anisotropy can be obtained and the strength would be increased after multi-passes CCDC.