The as-cast Mg-8Li-3Al-0.5Mn-xSr（LAM830-xSr, x=0-1.0） alloys were designed and prepared in a vacuum induction furnace under controlled argon atmosphere. The alloys were then processed by hot extrusion, and their mic...The as-cast Mg-8Li-3Al-0.5Mn-xSr（LAM830-xSr, x=0-1.0） alloys were designed and prepared in a vacuum induction furnace under controlled argon atmosphere. The alloys were then processed by hot extrusion, and their microstructural evolution and mechanical properties were analyzed. Results indicate that the LAM830 alloy mainly consists of α-Mg, β-Li, Al2Mn3, and LiMgAl2 phases. Sr addition results in the precipitation of Al-Sr. Moreover, Sr addition results in a fact that the secondary dendrite arm spacing（DAS） of the primary α-Mg phase is obvious refined. Microstructure of the investigated alloys is further refined as a result of the hot extrusion treatment. The content and morphology of the secondary phases have important effects on the mechanical properties of the alloys. The as-extruded LAM830-0.5Sr alloy exhibits an optimal elongation of 22.43% and as-extruded LAM830-0.75 Sr alloy shows an optimal tensile strength of 265.46 MPa.展开更多
The effects of Al-10Sr master alloys on grain refinement of AZ31 magnesium alloy were investigated,and the refinement efficiency of different Al-10Sr master alloys(commercial,solubilized,rolled and remelted+rapidly co...The effects of Al-10Sr master alloys on grain refinement of AZ31 magnesium alloy were investigated,and the refinement efficiency of different Al-10Sr master alloys(commercial,solubilized,rolled and remelted+rapidly cooled)was compared and analyzed.The results indicate that the morphology and size of Al4Sr phases in the microstructures of different Al-10Sr master alloys,are of great difference.For the commercial Al-10Sr master alloy,the Al4Sr phases evolve from coarse block shape to relatively fine block shape after being dissolved at 500 ℃ for 4 h and followed by water quenching;but after being rolled at 300 ℃ for 50% reduction or remelted and followed by rapid cooling,the Al4Sr phases mainly exhibit fine granule and fibre shapes.In addition,the different Al-10Sr master alloys can effectively reduce the grain size of AZ31 magnesium alloy,but their refinement efficiency is different.The refinement efficiency of the Al-10Sr master alloy obtained by remelting and rapid cooling is the best,then the rolled,solubilized and commercial Al-10Sr master alloys are in turn.The difference of refinement efficiency for different Al-10Sr master alloys may be related to the dissolution rates of Al4Sr phases with different morphologies and sizes in the melt of AZ31 magnesium alloy.展开更多
在AZ91D镁合金中仅添加Al_4Sr增强相,或复合添加Al_4Sr和石墨烯增强相,分析不同增强相对镁基复合材料的显微组织、耐磨损性能、耐腐蚀性能和高温力学性能的影响。结果表明,复合添合Al_4Sr和石墨烯增强相不仅明显提高材料的高温强度、耐...在AZ91D镁合金中仅添加Al_4Sr增强相,或复合添加Al_4Sr和石墨烯增强相,分析不同增强相对镁基复合材料的显微组织、耐磨损性能、耐腐蚀性能和高温力学性能的影响。结果表明,复合添合Al_4Sr和石墨烯增强相不仅明显提高材料的高温强度、耐磨损性能和耐腐蚀性能,还能改善材料的塑韧性。与未添加增强相的AZ91D镁合金相比,复合添合Al_4Sr和石墨烯增强相可使合金的150℃抗拉强度提高98.9%、屈服强度提高175.2%、断后伸长率基本不变,室温磨损体积减小85.5%,室温腐蚀电位正移198 m V。展开更多
基金Project(2007CB613702)supported by the National Basic Research Program of ChinaProject(2008BB4323)supported by the Natural Science Foundation of Chongqing Science and Technology Commission,ChinaProject(2010DFR50010)supported by the International Scientific and Technological Cooperation Projects,China
文摘The as-cast Mg-8Li-3Al-0.5Mn-xSr（LAM830-xSr, x=0-1.0） alloys were designed and prepared in a vacuum induction furnace under controlled argon atmosphere. The alloys were then processed by hot extrusion, and their microstructural evolution and mechanical properties were analyzed. Results indicate that the LAM830 alloy mainly consists of α-Mg, β-Li, Al2Mn3, and LiMgAl2 phases. Sr addition results in the precipitation of Al-Sr. Moreover, Sr addition results in a fact that the secondary dendrite arm spacing（DAS） of the primary α-Mg phase is obvious refined. Microstructure of the investigated alloys is further refined as a result of the hot extrusion treatment. The content and morphology of the secondary phases have important effects on the mechanical properties of the alloys. The as-extruded LAM830-0.5Sr alloy exhibits an optimal elongation of 22.43% and as-extruded LAM830-0.75 Sr alloy shows an optimal tensile strength of 265.46 MPa.
基金Project(50725413)supported by the National Natural Science Foundation for Distinguished Young Scholar in ChinaProject(2007CB613704)supported by the National Basic Research Program of China
文摘The effects of Al-10Sr master alloys on grain refinement of AZ31 magnesium alloy were investigated,and the refinement efficiency of different Al-10Sr master alloys(commercial,solubilized,rolled and remelted+rapidly cooled)was compared and analyzed.The results indicate that the morphology and size of Al4Sr phases in the microstructures of different Al-10Sr master alloys,are of great difference.For the commercial Al-10Sr master alloy,the Al4Sr phases evolve from coarse block shape to relatively fine block shape after being dissolved at 500 ℃ for 4 h and followed by water quenching;but after being rolled at 300 ℃ for 50% reduction or remelted and followed by rapid cooling,the Al4Sr phases mainly exhibit fine granule and fibre shapes.In addition,the different Al-10Sr master alloys can effectively reduce the grain size of AZ31 magnesium alloy,but their refinement efficiency is different.The refinement efficiency of the Al-10Sr master alloy obtained by remelting and rapid cooling is the best,then the rolled,solubilized and commercial Al-10Sr master alloys are in turn.The difference of refinement efficiency for different Al-10Sr master alloys may be related to the dissolution rates of Al4Sr phases with different morphologies and sizes in the melt of AZ31 magnesium alloy.
文摘在AZ91D镁合金中仅添加Al_4Sr增强相,或复合添加Al_4Sr和石墨烯增强相,分析不同增强相对镁基复合材料的显微组织、耐磨损性能、耐腐蚀性能和高温力学性能的影响。结果表明,复合添合Al_4Sr和石墨烯增强相不仅明显提高材料的高温强度、耐磨损性能和耐腐蚀性能,还能改善材料的塑韧性。与未添加增强相的AZ91D镁合金相比,复合添合Al_4Sr和石墨烯增强相可使合金的150℃抗拉强度提高98.9%、屈服强度提高175.2%、断后伸长率基本不变,室温磨损体积减小85.5%,室温腐蚀电位正移198 m V。
