Based on the Thomas-Fermi model,the calculation methods of the monatomic Gibbs free energy were found. The interior potential boundary condition under electric field was defined. The calculation methods of Gibbs free ...Based on the Thomas-Fermi model,the calculation methods of the monatomic Gibbs free energy were found. The interior potential boundary condition under electric field was defined. The calculation methods of Gibbs free energy for the monatomic,compound,and solid solution with electric field were set up. Under the influence of electric field,the Gibbs free energy of Al is the most sensitive,followed by those of Li and Mg. At the solution temperature the Gibbs free energies of Al3Li and its elements under electric field are not symmetrical about the zero point of electric field,whereas at the aging temperature their values are symmetrical about the zero point of electric field. At the solution temperature near the zero point of electric field,the Gibbs free energy of Al3Li is higher than that of Al-2.14%Li. And at 460 K the Gibbs free energy of Al3Li is lower than that of Al-2.14wt.%Li under electric field. The Gibbs free energy of 1420 alloy decreases from both sides of electric field to the zero point at the aging temperature.展开更多
To explore ambient strengthening and high temperature ductility,a combined forming approach of multidirectional forging and asymmetric rolling was proposed.A novel multicomponent ultralight Mg-3.11Li-2.31Al-1.95Sn-0.9...To explore ambient strengthening and high temperature ductility,a combined forming approach of multidirectional forging and asymmetric rolling was proposed.A novel multicomponent ultralight Mg-3.11Li-2.31Al-1.95Sn-0.94Y-0.45Er alloy was fabricated.The microstructural evolution and mechanical properties were investigated by microstructural characterization and tensile test.The combined forming results in remarkable grain refinement.The ultimate tensile strength and elongation of(255±7)MPa and 24.9%,respectively,were obtained at room temperature.The contribution of various strengthening mechanisms of the rolled alloy was obtained.Microstructural examination revealed the occurrence of dynamic recrystallization at 473-573 K and dynamic grain growth at 573-623 K.The maximum elongation of 293.9%was demonstrated at 623 K and 5×10^(-4)s^(-1).The dominate deformation mechanism at elevated temperatures is dislocation viscous glide.展开更多
研究了 Mg L i4Al和 Mg L i8Al合金的阻尼性能。结果表明 ,Mg- L i- Al合金的阻尼性能随锂含量的增多和温度的提高而明显增高。其中 Mg L i8Al合金的室温阻尼性能达到 Q- 1 =0 .0 1的高阻尼值。Mg L i8Al合金的阻尼明显大于Mg L i4Al合...研究了 Mg L i4Al和 Mg L i8Al合金的阻尼性能。结果表明 ,Mg- L i- Al合金的阻尼性能随锂含量的增多和温度的提高而明显增高。其中 Mg L i8Al合金的室温阻尼性能达到 Q- 1 =0 .0 1的高阻尼值。Mg L i8Al合金的阻尼明显大于Mg L i4Al合金的阻尼是由于 Mg L展开更多
基金the National Natural Science Foundation of China (No. 2003E103)the National High-Tech Research and Development Program of China (No. 2002AA331050)the Doctorate Foundation of North-western Polytechnical University (No. CX200507).
文摘Based on the Thomas-Fermi model,the calculation methods of the monatomic Gibbs free energy were found. The interior potential boundary condition under electric field was defined. The calculation methods of Gibbs free energy for the monatomic,compound,and solid solution with electric field were set up. Under the influence of electric field,the Gibbs free energy of Al is the most sensitive,followed by those of Li and Mg. At the solution temperature the Gibbs free energies of Al3Li and its elements under electric field are not symmetrical about the zero point of electric field,whereas at the aging temperature their values are symmetrical about the zero point of electric field. At the solution temperature near the zero point of electric field,the Gibbs free energy of Al3Li is higher than that of Al-2.14%Li. And at 460 K the Gibbs free energy of Al3Li is lower than that of Al-2.14wt.%Li under electric field. The Gibbs free energy of 1420 alloy decreases from both sides of electric field to the zero point at the aging temperature.
基金supported by the National Natural Science Foundation of China(No.51334006)。
文摘To explore ambient strengthening and high temperature ductility,a combined forming approach of multidirectional forging and asymmetric rolling was proposed.A novel multicomponent ultralight Mg-3.11Li-2.31Al-1.95Sn-0.94Y-0.45Er alloy was fabricated.The microstructural evolution and mechanical properties were investigated by microstructural characterization and tensile test.The combined forming results in remarkable grain refinement.The ultimate tensile strength and elongation of(255±7)MPa and 24.9%,respectively,were obtained at room temperature.The contribution of various strengthening mechanisms of the rolled alloy was obtained.Microstructural examination revealed the occurrence of dynamic recrystallization at 473-573 K and dynamic grain growth at 573-623 K.The maximum elongation of 293.9%was demonstrated at 623 K and 5×10^(-4)s^(-1).The dominate deformation mechanism at elevated temperatures is dislocation viscous glide.
文摘研究了 Mg L i4Al和 Mg L i8Al合金的阻尼性能。结果表明 ,Mg- L i- Al合金的阻尼性能随锂含量的增多和温度的提高而明显增高。其中 Mg L i8Al合金的室温阻尼性能达到 Q- 1 =0 .0 1的高阻尼值。Mg L i8Al合金的阻尼明显大于Mg L i4Al合金的阻尼是由于 Mg L
