| 1 | Solid-state alloying of Al-Mg alloys by accumulative roll-bonding:Microstructure and properties显示文摘In this study,a novel solid-state alloying approach was adopted to fabricate Al-Mg alloys with high Mg contents(C_(Mg)) by accumulative roll-bonding(ARB)of Al and Mg elemental materials to ultrahigh cycles.Experimental results showed that the degree of alloying increased with the increase of ARB cycles and a supersaturatedα-Al solid solution accompanied with nanoprecipitates was formed in the Al-Mg alloys by ARB to 70 cycles.The as-prepared Al-Mg alloys exhibited enhanced mechanical properties,with a maximum tensile strength of∼615 MPa and a tensile elongation of∼10%at C_(Mg)=13 wt.%.The high strength can be attributed to different mechanisms,namely solid solution strengthening,grain boundary strengthening,dislocation strengthening,and precipitation strengthening.The Al-Mg alloys showed increased work hardening with increasing C_(Mg),due to the enhanced formation of nanoprecipitates.Meanwhile,no obvious drop in the intergranular corrosion(IGC)resistance was found in the Al-Mg alloys with C_(Mg) up to 13 wt.%.Moreover,sensitization treatment was found to induce little decrease in the IGC resistance of the Al-Mg alloys with C_(Mg)≤13 wt.%.We found that the excellent IGC resistance was due to the suppression of grain boundary precipitation by the preferred formation of precipitates within the grains that were induced by ARB.Our study indicated the novelty of the present solid-state alloying approach to achieving a superior combination of high mechanical properties and IGC resistance in Al-Mg alloys. | X.M.Mei Q.S.Mei J.Y.Li C.L.Li L.Wan F.Chen Z.H.Chen T.Xu Y.C.Wang Y.Y.Tan | 2022 | Journal of Materials Science & Technology2022，，30： | 1 |
| 2 | Gradient microstructure,recrystallization and mechanical properties of copper processed by high pressure surface rolling显示文摘The microstructure,hardness and tensile properties have been studied in copper processed by high pressure surface rolling(HPSR)both in the as-deformed condition and after subsequent annealing at 150℃.It is found that a gradient structure with significant differences in the scale of microstructural features is formed by HPSR.The deformed microstructure varies from nano-and ultrafine-scale structures with a large fraction of high angle boundaries near the surface to lightly deformed grains at depths of 1-3 mm below the surface.Tensile tests of 1-mm-thick specimens demonstrate that the asdeformed material has a high strength and a low uniform elongation.Annealing at 150℃results in partial recrystallization,which creates new through-thickness gradients.Except for the topmost layer and several bands in the adjacent layer,recrystallization is more pronounced close to the surface.The fraction recrystallized is at least 80%at depths of 60-300μm after annealing for 960 min.The fraction recrystallized in the subsurface decreases with increasing depth,and the deformed layer at depths greater than 500μm re-mains largely non-recrystallized after annealing.This partially recrystallized condition demonstrates an improved combination of strength and ductility. | J.Guo Q.Y.He Q.S.Mei X.Huang G.L.Wu O.V.Mishin | 2022 | Journal of Materials Science & Technology2022，，31： | 1 |
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