High-quality LDH-NO_3-CO_3 whiskers were synthesized via a liquid precipitation method using Mg(NO_3)_2·6H_2O and Al(NO_3)_3·9H_2O as raw materials and Na_2CO_3-NaHCO_3 buffer solutions as precipitant. The w...High-quality LDH-NO_3-CO_3 whiskers were synthesized via a liquid precipitation method using Mg(NO_3)_2·6H_2O and Al(NO_3)_3·9H_2O as raw materials and Na_2CO_3-NaHCO_3 buffer solutions as precipitant. The whiskers were characterized by X-ray diffraction, transmission electron microscope, and Brunauer-Emmett-Teller N_2 surface area measurement. The influence of buffer solution concentration on the characteristics of the sample was investigated. The results show that the buffer solution concentration has significant impact on whiskers with intercalated structure. Overall, LDH-NO_3-CO_3 whiskers with well-defined geometry, distinct intercalated structure, high quality, and good dispersion capability can be obtained under the following conditions: buffer solution volumetric ratio of 60%, reaction temperature of 55°C, and reaction time of 269 h.展开更多
The microstructure of Mg-8Zn-4Al-1Ca aged alloy was investigated by TEM and HRTEM. The results show that the hardening produced in the Mg-8Zn-4Al-1Ca alloy is considerably higher than that in the Mg-8Zn-4A1 alloy. A d...The microstructure of Mg-8Zn-4Al-1Ca aged alloy was investigated by TEM and HRTEM. The results show that the hardening produced in the Mg-8Zn-4Al-1Ca alloy is considerably higher than that in the Mg-8Zn-4A1 alloy. A dense dispersion of disc-like Ca2Mg6Zn3 precipitates are formed in Mg-8Zn-4Al-1Ca alloy aged at 160 ℃ for 16 h. In addition, the lattice distortions, honeycomb-looking Moir＆#233; fringes, edge dislocations and dislocation loop also exist in the microstructure. The precipitates of alloy aged at 160 ℃ for 48 h are coarse disc-like and fine dispersed grainy. When the alloy is subjected to aging at 160 ℃ for 227 h, the microstructure consists of numerous MgZn2 precipitates and Ca2Mg6Zn3 precipitates. All the analyses show that Ca is a particularly effective trace addition in improving the age-hardening and postponing the formation of MgZn2 precipitates in Mg-8Zn-4Al alloy aged at 160 ℃.展开更多
文摘High-quality LDH-NO_3-CO_3 whiskers were synthesized via a liquid precipitation method using Mg(NO_3)_2·6H_2O and Al(NO_3)_3·9H_2O as raw materials and Na_2CO_3-NaHCO_3 buffer solutions as precipitant. The whiskers were characterized by X-ray diffraction, transmission electron microscope, and Brunauer-Emmett-Teller N_2 surface area measurement. The influence of buffer solution concentration on the characteristics of the sample was investigated. The results show that the buffer solution concentration has significant impact on whiskers with intercalated structure. Overall, LDH-NO_3-CO_3 whiskers with well-defined geometry, distinct intercalated structure, high quality, and good dispersion capability can be obtained under the following conditions: buffer solution volumetric ratio of 60%, reaction temperature of 55°C, and reaction time of 269 h.
基金Project(51141007)supported by the National Natural Science Foundation of ChinaProject(E2013501096)supported by Hebei Province Natural Science Foundation,China
文摘The microstructure of Mg-8Zn-4Al-1Ca aged alloy was investigated by TEM and HRTEM. The results show that the hardening produced in the Mg-8Zn-4Al-1Ca alloy is considerably higher than that in the Mg-8Zn-4A1 alloy. A dense dispersion of disc-like Ca2Mg6Zn3 precipitates are formed in Mg-8Zn-4Al-1Ca alloy aged at 160 ℃ for 16 h. In addition, the lattice distortions, honeycomb-looking Moir＆#233; fringes, edge dislocations and dislocation loop also exist in the microstructure. The precipitates of alloy aged at 160 ℃ for 48 h are coarse disc-like and fine dispersed grainy. When the alloy is subjected to aging at 160 ℃ for 227 h, the microstructure consists of numerous MgZn2 precipitates and Ca2Mg6Zn3 precipitates. All the analyses show that Ca is a particularly effective trace addition in improving the age-hardening and postponing the formation of MgZn2 precipitates in Mg-8Zn-4Al alloy aged at 160 ℃.
