Microstructure, mechanical properties and wear resistance of an Al–Mg–Si alloy produced by equal channel angular pressing
Microstructure, mechanical properties and wear resistance of an Al–Mg–Si alloy produced by equal channel angular pressing
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等通道角挤压Al-Mg-Si合金的显微组织、力学性能及耐磨性能
DOI：
10.1016/j.pnsc.2020.07.005
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Pål C. Skaret
中科院分区：
文献类型：
--
作者：
Manping Liu;Jian Chen;Yaojun Lin;Zhoulei Xue;Hans J. Roven;Pål C. Skaret
研究了等径角挤压（ECAP）与动态时效相结合制备的超细晶Al-Mg-Si合金的显微组织、力学性能和耐磨性。结果表明，ECAP变形后合金的晶粒尺寸明显细化，在三次ECAP通过之后，至~239 nm。同时，ECAP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14%的显著均匀延伸率。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，ECAP处理的材料的磨损率、磨损深度和磨损宽度降低。在10 N下未变形试样中发生的粘着磨损在相同载荷下的ECAP试样中没有出现，表明ECAP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”相与位错的协同作用，使合金具有超高强度和良好的加工硬化能力，抑制了摩擦层与塑性变形区之间裂纹的扩展。结果表明，ECAP和动态时效相结合可显著提高6061铝合金的减摩性能。
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.