Mg−1Mn−0.5Al−0.5Ca−0.5Zn(wt.%)alloy was fabricated by conventional extrusion at 673 K with an extrusion ratio of 25:1,followed by aging at 473 K.The microstructure was characterized by scanning electron microscopy,ele...Mg−1Mn−0.5Al−0.5Ca−0.5Zn(wt.%)alloy was fabricated by conventional extrusion at 673 K with an extrusion ratio of 25:1,followed by aging at 473 K.The microstructure was characterized by scanning electron microscopy,electron back-scattered diffraction,and transmission electron microscopy.The mechanical properties were determined by the tensile test.The peak-aged sample shows fine recrystallized grains with an average grain size of 1.7μm.Area fraction of Al−Ca particles in the alloy increases significantly after peak aging.Meanwhile,botháañandác+añdislocations were observed to remain in the alloy after hot extrusion.Thus,the peak-aged sample exhibits simultaneously high strength and good ductility with the ultimate tensile stress,tensile yield stress,and tension fracture elongation of 320 MPa,314 MPa,and 19.0%,respectively.展开更多
To investigate the effect of separate Al_(2)Ca and Mg_(2)Ca phases on the corrosion properties of Mg−Al−Ca−Mn alloys,OM,SEM,immersion and electrochemical tests were conducted on the as-cast and ECAP Al_(2)Ca-containin...To investigate the effect of separate Al_(2)Ca and Mg_(2)Ca phases on the corrosion properties of Mg−Al−Ca−Mn alloys,OM,SEM,immersion and electrochemical tests were conducted on the as-cast and ECAP Al_(2)Ca-containing(2Ca)and Mg_(2)Ca-containing(4Ca)alloys.At the beginning of corrosion,the two as-cast alloys are corroded slowly compared with ECAP alloys.With prolonging the corrosion time,the corrosion of ECAP alloys becomes slighter than that of as-cast alloys,which is mainly ascribed to the dispersion and refinement of the second phase in ECAP alloys.Moreover,the corrosion degree of 2Ca alloys is always slighter than that of 4Ca alloys,suggesting that Al_(2)Ca phase is more beneficial to the enhancement of corrosion resistance of Mg−Al−Ca−Mn based alloys than Mg_(2)Ca phase.Finally,based on the examinations of corrosion surface and electrochemical testing results,different corrosion mechanisms caused by the distributions and morphology of Al_(2)Ca and Mg_(2)Ca phases are discussed.展开更多
Herein,the effects of Ca content on microstructure,texture and mechanical properties of extruded Mg–3Al–0.4Mn–xCa(x=0.4,0.8 and 1.2 wt%)rods are systematically investigated.The results reveal that the alloy,with Ca...Herein,the effects of Ca content on microstructure,texture and mechanical properties of extruded Mg–3Al–0.4Mn–xCa(x=0.4,0.8 and 1.2 wt%)rods are systematically investigated.The results reveal that the alloy,with Ca content of 0.8 wt%,exhibits the highest strength and ductility,possessing an ultimate tensile strength of 267.57 MPa and elongation(EL)of 16%.This is mainly due to the gradual transformation of typical fiber texture into a texture with a[10-11]component parallel to the extrusion direction(ED),which increases the Schmid factor of pyramidal slip and enhances the activation rate of pyramidal(c+a)slip.Simultaneously,the as-formed spherical phases and segregation of Ca at grain boundaries render a significant influence on the strength and ductility of the alloy.展开更多
基金the financial supports from the Fundamental Research Funds for the Central Universities,China(Nos.2019CDCGCL316,2020CDJDPT001)Chongqing Research Program of Basic Research and Frontier Technology,China(No.cstc2019jcjy-msxmX0539)。
文摘Mg−1Mn−0.5Al−0.5Ca−0.5Zn(wt.%)alloy was fabricated by conventional extrusion at 673 K with an extrusion ratio of 25:1,followed by aging at 473 K.The microstructure was characterized by scanning electron microscopy,electron back-scattered diffraction,and transmission electron microscopy.The mechanical properties were determined by the tensile test.The peak-aged sample shows fine recrystallized grains with an average grain size of 1.7μm.Area fraction of Al−Ca particles in the alloy increases significantly after peak aging.Meanwhile,botháañandác+añdislocations were observed to remain in the alloy after hot extrusion.Thus,the peak-aged sample exhibits simultaneously high strength and good ductility with the ultimate tensile stress,tensile yield stress,and tension fracture elongation of 320 MPa,314 MPa,and 19.0%,respectively.
基金financial supports from the National Natural Science Foundation of China (Nos.51901068,51979099)the Key Research and Development Project of Jiangsu Province,China (No.BE2021027)+1 种基金the Opening Project of Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology,China (No.ASMA202102)the Research Fund from Key Laboratory for Light-weight Materials of Jiangsu Province,China。
文摘To investigate the effect of separate Al_(2)Ca and Mg_(2)Ca phases on the corrosion properties of Mg−Al−Ca−Mn alloys,OM,SEM,immersion and electrochemical tests were conducted on the as-cast and ECAP Al_(2)Ca-containing(2Ca)and Mg_(2)Ca-containing(4Ca)alloys.At the beginning of corrosion,the two as-cast alloys are corroded slowly compared with ECAP alloys.With prolonging the corrosion time,the corrosion of ECAP alloys becomes slighter than that of as-cast alloys,which is mainly ascribed to the dispersion and refinement of the second phase in ECAP alloys.Moreover,the corrosion degree of 2Ca alloys is always slighter than that of 4Ca alloys,suggesting that Al_(2)Ca phase is more beneficial to the enhancement of corrosion resistance of Mg−Al−Ca−Mn based alloys than Mg_(2)Ca phase.Finally,based on the examinations of corrosion surface and electrochemical testing results,different corrosion mechanisms caused by the distributions and morphology of Al_(2)Ca and Mg_(2)Ca phases are discussed.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52105140,52174362 and 51975207)the Natural Science Foundation of Hunan Province(Grant No.2021JJ40583)the Education Department of Hunan Province of China(Grant No.21C0177).
文摘Herein,the effects of Ca content on microstructure,texture and mechanical properties of extruded Mg–3Al–0.4Mn–xCa(x=0.4,0.8 and 1.2 wt%)rods are systematically investigated.The results reveal that the alloy,with Ca content of 0.8 wt%,exhibits the highest strength and ductility,possessing an ultimate tensile strength of 267.57 MPa and elongation(EL)of 16%.This is mainly due to the gradual transformation of typical fiber texture into a texture with a[10-11]component parallel to the extrusion direction(ED),which increases the Schmid factor of pyramidal slip and enhances the activation rate of pyramidal(c+a)slip.Simultaneously,the as-formed spherical phases and segregation of Ca at grain boundaries render a significant influence on the strength and ductility of the alloy.
