This study was conducted to discuss the effect of rolling strain on microstructure and tensile properties of dual-phase Mg-8Li-3Al-2Zn-0.5 Y（wt%） alloy, which was prepared by casting, and then homogenized and rolled...This study was conducted to discuss the effect of rolling strain on microstructure and tensile properties of dual-phase Mg-8Li-3Al-2Zn-0.5 Y（wt%） alloy, which was prepared by casting, and then homogenized and rolled at 200℃. The rolling process was conducted with 10% reduction per pass and five different accumulated strains, varying from 10% to 70%. The results indicate that the as-cast and as-rolled Mg-8Li-3Al-2Zn-0.5Y alloys are composed of α-Mg, β-Li, AlLi and Al;Y phases. After rolling process,anisotropic microstructure was observed. a-Mg phase got elongated in both rolling direction and transverse direction with the addition of rolling strain. Consequently, the strength of the alloy in both directions was notably improved whereas the elongation declined, mainly caused by strain hardening and dispersion strengthening. The tensile properties of the as-rolled alloys in the RD, no matter the YS, UTS or the elongation, are higher than those of the TD due to their larger deformation strain and significant anisotropy in the hcp α-Mg phase. In addition, the fracture and strengthening mechanism of the tested alloys were also investigated systematically.展开更多
Y_2(p-CH_3C_6H_4COO)_6(C_(12)H_8N_2)_2, Mr=1349.08, triclinic, space group P, a=13.00(3), b=19.743(2), c=12.754(3)A, α=97.94(1), β=106.24(2), γ=91.66(1)°, V=3177(1)~3, Z=2, Dc=1.41gcm^(-3), λ(MoKα)=0.71069, ...Y_2(p-CH_3C_6H_4COO)_6(C_(12)H_8N_2)_2, Mr=1349.08, triclinic, space group P, a=13.00(3), b=19.743(2), c=12.754(3)A, α=97.94(1), β=106.24(2), γ=91.66(1)°, V=3177(1)~3, Z=2, Dc=1.41gcm^(-3), λ(MoKα)=0.71069, μ=18.92 cm^(-1), F(ooo)=1384, T=295K, final R=0.073 for 6504 observed reflections with Ⅰ>36(Ⅰ). There are two nonidentical binuclear molecules with different bridging connection patterns in a cell. One has four bridging carboxyl groups bound two Y(Ⅲ) ions and another only has two. The Y-Y distance is 4.196 for the former and 5.302 for the latter respectively.展开更多
A new kind of aluminium-based alloy part amorphous/part crystalline, can be produced directlyby rapid quenching of the liquid. These materials have a novel structure of nanometer-sizedcrystals in an amorphous matrix a...A new kind of aluminium-based alloy part amorphous/part crystalline, can be produced directlyby rapid quenching of the liquid. These materials have a novel structure of nanometer-sizedcrystals in an amorphous matrix and quite remarkable mechanical properties. The materialscan be considered to be nanophase composites. In this work Al88Ni10Y2 and Al88Ni8Y4 (atpct) nanophase composites consisting of a nanoscale dispersion of fcc-Al crystallites uniformlydispersed in an amorphous matrix, have been produced by melt-spinning. They have much highermicrohardness HV than fully amorphous alloys with the same composition. while retaining goodbending ductility The volume fraction, crystallite size and distribution of the fcc-Al phase havebeen estimated by DSC. X-ray diffraction and TEM. lt is found that the microstructure andproperties of the nanophase composites are very sensitive to the composition and the quenchingconditions. lncreasing the Y contedt and decreasing the Ni content at a given Al content givesmuch smaller dispersed nanophase aluminium crystallites. The volume fraction and crystallitesize of the fcc-Al phase increase with a decrease of wheel speed (quenching rate). The effectsof Y and Ni contents on the ease of formaticn of the nanophase composites are discussed. Theorigins of the novel mechanical properties are also considered.展开更多
基金supported by the National Key Research and Development Program of China(No.2016YFB0301004)the National Natural Science Foundation of China(No.51771115)+1 种基金the Science and Technology Innovation Project(No.009-031-001)Research Program of Joint Research Center of Advanced Spaceflight Technologies(Nos.USCAST2015-25 and USCAST2016-18)
文摘This study was conducted to discuss the effect of rolling strain on microstructure and tensile properties of dual-phase Mg-8Li-3Al-2Zn-0.5 Y（wt%） alloy, which was prepared by casting, and then homogenized and rolled at 200℃. The rolling process was conducted with 10% reduction per pass and five different accumulated strains, varying from 10% to 70%. The results indicate that the as-cast and as-rolled Mg-8Li-3Al-2Zn-0.5Y alloys are composed of α-Mg, β-Li, AlLi and Al;Y phases. After rolling process,anisotropic microstructure was observed. a-Mg phase got elongated in both rolling direction and transverse direction with the addition of rolling strain. Consequently, the strength of the alloy in both directions was notably improved whereas the elongation declined, mainly caused by strain hardening and dispersion strengthening. The tensile properties of the as-rolled alloys in the RD, no matter the YS, UTS or the elongation, are higher than those of the TD due to their larger deformation strain and significant anisotropy in the hcp α-Mg phase. In addition, the fracture and strengthening mechanism of the tested alloys were also investigated systematically.
文摘Y_2(p-CH_3C_6H_4COO)_6(C_(12)H_8N_2)_2, Mr=1349.08, triclinic, space group P, a=13.00(3), b=19.743(2), c=12.754(3)A, α=97.94(1), β=106.24(2), γ=91.66(1)°, V=3177(1)~3, Z=2, Dc=1.41gcm^(-3), λ(MoKα)=0.71069, μ=18.92 cm^(-1), F(ooo)=1384, T=295K, final R=0.073 for 6504 observed reflections with Ⅰ>36(Ⅰ). There are two nonidentical binuclear molecules with different bridging connection patterns in a cell. One has four bridging carboxyl groups bound two Y(Ⅲ) ions and another only has two. The Y-Y distance is 4.196 for the former and 5.302 for the latter respectively.
文摘A new kind of aluminium-based alloy part amorphous/part crystalline, can be produced directlyby rapid quenching of the liquid. These materials have a novel structure of nanometer-sizedcrystals in an amorphous matrix and quite remarkable mechanical properties. The materialscan be considered to be nanophase composites. In this work Al88Ni10Y2 and Al88Ni8Y4 (atpct) nanophase composites consisting of a nanoscale dispersion of fcc-Al crystallites uniformlydispersed in an amorphous matrix, have been produced by melt-spinning. They have much highermicrohardness HV than fully amorphous alloys with the same composition. while retaining goodbending ductility The volume fraction, crystallite size and distribution of the fcc-Al phase havebeen estimated by DSC. X-ray diffraction and TEM. lt is found that the microstructure andproperties of the nanophase composites are very sensitive to the composition and the quenchingconditions. lncreasing the Y contedt and decreasing the Ni content at a given Al content givesmuch smaller dispersed nanophase aluminium crystallites. The volume fraction and crystallitesize of the fcc-Al phase increase with a decrease of wheel speed (quenching rate). The effectsof Y and Ni contents on the ease of formaticn of the nanophase composites are discussed. Theorigins of the novel mechanical properties are also considered.
