预变形对Al-Mg-Si-Cu合金时效硬化和显微结构的影响

发布时间：2018-12-17 18:45

【摘要】：采用显微硬度测试、拉伸实验、EBSD和TEM等检测手段研究了不同变形量对形变和时效结合制备的Al-Mg-Si-Cu合金力学性能和显微结构的影响.结果表明,随着变形量的增加,轧制态合金的硬度会逐渐增加,后续时效过程中形变合金均能进一步强化但时效硬化能力逐渐下降;晶粒沿着轧制方向逐渐被拉长为层状结构,形成大量亚晶界.变形量小时,合金内位错密度随着形变量的增加而增加;变形量较大时,位错发生缠结并形成亚晶.形变导致的位错组态变化显著影响合金的析出特性,析出相逐渐从离散分布演变为连续分布,连续分布的析出相是溶质原子析出与缺陷退化交互作用的结果,通过调整形变量和时效工艺有助于制备强度和塑性结合良好的铝合金.
[Abstract]:The effects of different deformations on the mechanical properties and microstructure of the Al-Mg-Si-Cu alloy prepared by the combination of deformation and aging were studied by means of microhardness test, tensile test, EBSD and TEM. The results show that the hardness of the rolled alloy increases with the increase of the amount of deformation, and the aging hardening ability of all the alloys can be further strengthened but the aging hardening ability decreases gradually during the subsequent aging process. Along the rolling direction, the grain is gradually elongated into a layered structure, forming a large number of sub-grain boundaries. The dislocation density in the alloy increases with the increase of the shape variable, and when the deformation is large, the dislocation becomes entangled and forms subcrystal. The dislocation configuration caused by deformation has a significant effect on the precipitation characteristics of the alloy. The precipitate phase gradually evolves from discrete distribution to continuous distribution. The continuous distribution of precipitated phase is the result of interaction between solute atom precipitation and defect degradation. By adjusting shape variables and aging process, aluminum alloy with good strength and plasticity can be prepared.
【作者单位】：湖南大学材料科学与工程学院;
【基金】：国家自然科学基金项目51171063和11427806 国家重点基础研究发展计划项目2009CB623704资助~~
【分类号】：TG166.3;TG146.21

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