High-entropy alloy particles(HEAPs)can markedly enhance the mechanical properties of metal matrix composites(MMCs).In this study,AA5083/Al_(0.5) CoCrFeNi HEAPs MMCs with diff erent HEAPs contents(0,1,and 3 wt%)were pr...High-entropy alloy particles(HEAPs)can markedly enhance the mechanical properties of metal matrix composites(MMCs).In this study,AA5083/Al_(0.5) CoCrFeNi HEAPs MMCs with diff erent HEAPs contents(0,1,and 3 wt%)were prepared via a stir-casting,and then these MMCs sheets were hot rolled(573 K)and cryorolled(77 K),respectively.The mechanical properties of the MMCs sheets were measured by tensile testing and microhardness test.Additionally,their microstructures were analyzed by scanning electron microscopy and transmission electron microscopy.Results revealed that the ultimate tensile strength(UTS)of the as-cast AA5083/Al_(0.5) CoC rF eN i HEAPs MMCs were improved from 203 to 257 MPa by adding 3 wt%HEAPs.And the mechanical properties of the MMCs sheets were improved after cryorolling.After cryorolling with 50%rolling reduction ratio,the MMCs with 1 wt%HEAPs had an UTS of 382 MPa,which was 1.9 times that of the MMCs before rolling.Finally,the strengthening mechanisms of HEAPs and cryorolling on the AA5083/HEAPs MMCs were discussed.展开更多
Ultra fine-grained pure metals and their alloys have high strength and low ductility.In this study,cryorolling under different strains followed by low-temperature short-time annealing was used to fabricate pure nickel...Ultra fine-grained pure metals and their alloys have high strength and low ductility.In this study,cryorolling under different strains followed by low-temperature short-time annealing was used to fabricate pure nickel sheets combining high strength with good ductility.The results show that,for different cryorolling strains,the uniform elongation was greatly increased without sacrificing the strength after annealing.A yield strength of 607 MPa and a uniform elongation of 11.7%were obtained after annealing at a small cryorolling strain(ε=0.22),while annealing at a large cryorolling strain(ε=1.6)resulted in a yield strength of 990 MPa and a uniform elongation of 6.4%.X-ray diffraction(XRD),transmission electron microscopy(TEM),scanning electron microscopy(SEM),and electron backscattered diffraction(EBSD)were used to characterize the microstructure of the specimens and showed that the high strength could be attributed to strain hardening during cryorolling,with an additional contribution from grain refinement and the formation of dislocation walls.The high ductility could be attributed to annealing twins and micro-shear bands during stretching,which improved the strain hardening capacity.The results show that the synergistic effect of strength and ductility can be regulated through low-temperature short-time annealing with different cryorolling strains,which provides a new reference for the design of future thermo-mechanical processes.展开更多
基金financially supported by the National Key Research and Development Program(Grant No.2019YFB2006500)the Huxiang High-Level Talent Gathering Project of HUNAN Province(Grant No.2018RS3015)+4 种基金Innovation Driven Program of Central South University(Grant No.2019CX006)the Science and Technology Innovation Program of Hunan Province(Grant No.2020RC2002)the Natural Science Foundation of Hunan Province(Grant No.2021JJ40774)the Fundamental Research Funds for the Central Universities of Central South University(Grant No.2021zzts0150)the Research Fund of the Key Laboratory of High Performance Complex Manufacturing at Central South University。
文摘High-entropy alloy particles(HEAPs)can markedly enhance the mechanical properties of metal matrix composites(MMCs).In this study,AA5083/Al_(0.5) CoCrFeNi HEAPs MMCs with diff erent HEAPs contents(0,1,and 3 wt%)were prepared via a stir-casting,and then these MMCs sheets were hot rolled(573 K)and cryorolled(77 K),respectively.The mechanical properties of the MMCs sheets were measured by tensile testing and microhardness test.Additionally,their microstructures were analyzed by scanning electron microscopy and transmission electron microscopy.Results revealed that the ultimate tensile strength(UTS)of the as-cast AA5083/Al_(0.5) CoC rF eN i HEAPs MMCs were improved from 203 to 257 MPa by adding 3 wt%HEAPs.And the mechanical properties of the MMCs sheets were improved after cryorolling.After cryorolling with 50%rolling reduction ratio,the MMCs with 1 wt%HEAPs had an UTS of 382 MPa,which was 1.9 times that of the MMCs before rolling.Finally,the strengthening mechanisms of HEAPs and cryorolling on the AA5083/HEAPs MMCs were discussed.
基金the financial support from the High-Tech Industry Technology Innovation Leading Plan of Hunan Province,China(2020GK2032)the Innovation Driven Program of Central South University(CSU)(2019CX006)the Research Fund of the Key Laboratory of High Performance Complex Manufacturing at CSU。
文摘Ultra fine-grained pure metals and their alloys have high strength and low ductility.In this study,cryorolling under different strains followed by low-temperature short-time annealing was used to fabricate pure nickel sheets combining high strength with good ductility.The results show that,for different cryorolling strains,the uniform elongation was greatly increased without sacrificing the strength after annealing.A yield strength of 607 MPa and a uniform elongation of 11.7%were obtained after annealing at a small cryorolling strain(ε=0.22),while annealing at a large cryorolling strain(ε=1.6)resulted in a yield strength of 990 MPa and a uniform elongation of 6.4%.X-ray diffraction(XRD),transmission electron microscopy(TEM),scanning electron microscopy(SEM),and electron backscattered diffraction(EBSD)were used to characterize the microstructure of the specimens and showed that the high strength could be attributed to strain hardening during cryorolling,with an additional contribution from grain refinement and the formation of dislocation walls.The high ductility could be attributed to annealing twins and micro-shear bands during stretching,which improved the strain hardening capacity.The results show that the synergistic effect of strength and ductility can be regulated through low-temperature short-time annealing with different cryorolling strains,which provides a new reference for the design of future thermo-mechanical processes.
