Yüzey Mekanik Aşındırma ile Oluşturulan Hiyerarşik Nanoyapı, Mg Alaşımlarında Yüksek Mukavemet ve Orta Derecede Süneklik Sağlıyor

Özet (abstract)

The engineering application of lightweight structural magnesium (Mg) alloys is usually impeded by the challenge of achieving high strength together with useful tensile ductility. In this study, rare-earth-free Mg-6Sn-3Zn-0.3Zr alloys with ultimate tensile strengths (UTS) of 385–405 MPa, tensile yield strengths (TYS) of 320–365 MPa and elongations (Els.) of approximately 13% were developed by constructing gradient nanostructures via surface mechanical attrition treatment (SMAT). Microstructural results revealed a hierarchical gradient architecture consisting of a nanograined surface layer, an ultrafine substructured transition layer and a coarse-grained core. The surface nanograins were formed through dislocation accumulation, twinning-assisted grain subdivision, subgrain rotation and in-situ dynamic recrystallization, accompanied by second-phase fragmentation and redistribution. The enhanced strength was mainly attributed to nanocrystalline strengthening, particle-assisted hardening, dislocation/substructure hardening and gradient-structure-induced hetero-deformation-induced (HDI) strengthening, while the retained ductility was enabled by HDI hardening and strain accommodation in the defect-rich transition layer and coarse core. This work demonstrates an effective SMAT-based gradient-design strategy for overcoming the strength-ductility trade-off in rare-earth-free Mg alloys.

Yazarların özeti; kaynağından alınmıştır. Journal of Magnesium and Alloys, 2026 · DOI ↗