Abstract Microstructure, mechanical properties and wear resistance in an ultrafine-grained Al–Mg–Si alloy fabricated utilizing a combination of equal channel angular pressing (ECAP) and dynamic aging were investigated in this paper. The results indicated that the grain size of the ECAP alloy was significantly refined, i.e., to ~239 nm after three ECAP passes. Meanwhile, the yield and tensile strength of the ECAPed material reached 340 MPa and 445 MPa, respectively, while maintaining a significant uniform elongation of 14%. Wear resistance results demonstrated that the wear rate, wear depth and width of the ECAPed material decreased in comparison with the solution-treated (SST) and peak-aged (T6) conditions under a load range of 5–25 N. The adhesive wear that occurs in the undeformed specimens at 10 N does not appear in the ECAPed specimen at the same load, indicating that the ECAPed specimen delay the appearance of more serious wear mechanisms under certain loads. The cooperative interaction of high density nano-scale β" precipitates and dislocations resulted in a combination of super-high strength and good work hardening ability which suppressed the extension of cracks between the friction layer and the plastic deformation zone. As a consequence, the combination of ECAP and dynamic aging brings a significant improvement for antifriction performance of the 6061 aluminum alloy.

中文翻译：

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等通道角压法制备的Al-Mg-Si合金的显微组织、力学性能和耐磨性

摘要 本文研究了等通道角挤压 (ECAP) 和动态时效相结合制备的超细晶 Al-Mg-Si 合金的显微组织、机械性能和耐磨性。结果表明，ECAP 合金的晶粒尺寸在三个 ECAP 通过后显着细化，即达到~239 nm。同时，ECAPed 材料的屈服强度和拉伸强度分别达到 340 MPa 和 445 MPa，同时保持了 14% 的显着均匀伸长率。耐磨性结果表明，在 5-25 N 的载荷范围内，与固溶处理 (SST) 和峰值时效 (T6) 条件相比，ECAPed 材料的磨损率、磨损深度和宽度降低。未变形试样在 10 N 下发生的粘着磨损在相同载荷下的 ECAPed 试样中没有出现，表明 ECAPed 试样在某些载荷下延迟了更严重磨损机制的出现。高密度纳米级 β" 析出物和位错的协同作用导致超高强度和良好的加工硬化能力相结合，抑制了摩擦层和塑性变形区之间裂纹的扩展。因此，这种组合ECAP 和动态时效为 6061 铝合金的减摩性能带来显着改善。析出物和位错导致超高强度和良好的加工硬化能力相结合，抑制了摩擦层和塑性变形区之间裂纹的扩展。因此，ECAP 和动态时效的结合为 6061 铝合金的减摩性能带来了显着的改善。析出物和位错导致超高强度和良好的加工硬化能力相结合，抑制了摩擦层和塑性变形区之间裂纹的扩展。因此，ECAP 和动态时效的结合为 6061 铝合金的减摩性能带来了显着的改善。