In order to investigate the existing form and action mechanism of minor scandium （Sc） and zirconium （Zr） in AI-Cu-Mg alloy, microstructures of Al-4Cu-1Mg-Sc-Zr alloy under different conditions, including states of...In order to investigate the existing form and action mechanism of minor scandium （Sc） and zirconium （Zr） in AI-Cu-Mg alloy, microstructures of Al-4Cu-1Mg-Sc-Zr alloy under different conditions, including states of as-cast, homogenized, hot-rolled, as-solution and natural aged, were observed by scanning electron microscopy （SEM）, X-ray diffractometry （XRD） and transmission electron microscopy （TEM）. It is revealed that Sc and Zr are completely dissolved into the supersaturated solid solution in as-cast ingot, but grain refinement is not observed. Coffee-bean-like AI3（Sc, Zr） particles deposit during homogenization of ingot induce an increase in hardness. Al3（Sc, Zr） particles are slightly coarsened in as-solution samples, but they still maintain coherent to matrix, which indicates a high thermal stability of these particles. Good coherency ofAl3（Sc, Zr） particles makes some benefits for inhibiting recrystallization and reserving work-hardening.展开更多
The ignition-proof mechanism of ZM5 magnesium alloy added with 0.1% （mass fraction） rare earth （RE） was investigated. The oxide scales and substrates were characterized by scanning electronic microscope （SEM）, X...The ignition-proof mechanism of ZM5 magnesium alloy added with 0.1% （mass fraction） rare earth （RE） was investigated. The oxide scales and substrates were characterized by scanning electronic microscope （SEM）, X-ray diffraction （XRD）, energy dispersive spectrometer （EDS） and tensile test. And an oxidation model of ZM5 alloy with RE was established. The results show that the ignition temperature of ZM5 alloy is particularly elevated from 654 to 823 ℃, the microstructure is refined, and the tensile strength is slightly improved from 168.2 to 174.6 MPa by adding 0.1% RE. A double-layer oxidation film formed on the alloy surface under high temperature mainly consists of MgO, RE203 and A1203, which is 2.5-3.5 μm in thickness. It is found that the forming of protective oxidation film on the thermodynamics is attributed to RE elements congregating on the surface of molten Mg alloy.展开更多
基金Project(2005DFA50550) supported by International Science and Technology Cooperation Program of ChinaProject(2005CB623705) supported by the National Basic Research Program of China
文摘In order to investigate the existing form and action mechanism of minor scandium （Sc） and zirconium （Zr） in AI-Cu-Mg alloy, microstructures of Al-4Cu-1Mg-Sc-Zr alloy under different conditions, including states of as-cast, homogenized, hot-rolled, as-solution and natural aged, were observed by scanning electron microscopy （SEM）, X-ray diffractometry （XRD） and transmission electron microscopy （TEM）. It is revealed that Sc and Zr are completely dissolved into the supersaturated solid solution in as-cast ingot, but grain refinement is not observed. Coffee-bean-like AI3（Sc, Zr） particles deposit during homogenization of ingot induce an increase in hardness. Al3（Sc, Zr） particles are slightly coarsened in as-solution samples, but they still maintain coherent to matrix, which indicates a high thermal stability of these particles. Good coherency ofAl3（Sc, Zr） particles makes some benefits for inhibiting recrystallization and reserving work-hardening.
基金Project(2004BB8429) supported by Chongqing Municipal Science and Technology Commission, China
文摘The ignition-proof mechanism of ZM5 magnesium alloy added with 0.1% （mass fraction） rare earth （RE） was investigated. The oxide scales and substrates were characterized by scanning electronic microscope （SEM）, X-ray diffraction （XRD）, energy dispersive spectrometer （EDS） and tensile test. And an oxidation model of ZM5 alloy with RE was established. The results show that the ignition temperature of ZM5 alloy is particularly elevated from 654 to 823 ℃, the microstructure is refined, and the tensile strength is slightly improved from 168.2 to 174.6 MPa by adding 0.1% RE. A double-layer oxidation film formed on the alloy surface under high temperature mainly consists of MgO, RE203 and A1203, which is 2.5-3.5 μm in thickness. It is found that the forming of protective oxidation film on the thermodynamics is attributed to RE elements congregating on the surface of molten Mg alloy.
