The surface of AZ91 D magnesium alloy was remelted by plasma beam. The microstructure, composition, hardness, wear and corrosion resistance of the plasma remelted layer（PRL） were characterized. The results show that...The surface of AZ91 D magnesium alloy was remelted by plasma beam. The microstructure, composition, hardness, wear and corrosion resistance of the plasma remelted layer（PRL） were characterized. The results show that there is extremely fine and dendrite structure in the PRL at low magnification observation, which is still composed of α-Mg and β-Mg17Al12 phases. But at high magnification observation, the microstructure of the PRL is equiaxial crystalline grains with size of 3-5 μm. And also the content of α-Mg phase decreases while that of β-Mg17Al12 increases and distributes more uniformly in α-Mg matrix compared with the substrate. The hardness of the PRL is much higher than that of the substrate. There are plastic deformation, grains uprooting and tearing evidence with tiny even dimples in the tensile fracture of the PRL, which are different from the substrate. Furthermore, the surface wear and corrosion resistance of AZ91 D are improved significantly after plasma remelting.展开更多
So far super heavy elements are synthesized by cold fusion of heavy ions with Pb and Bi targets, or hot fusion reaction using 232Th, 238U and 242>244Pu targets. Further heavier synthesizing could be very difficult....So far super heavy elements are synthesized by cold fusion of heavy ions with Pb and Bi targets, or hot fusion reaction using 232Th, 238U and 242>244Pu targets. Further heavier synthesizing could be very difficult. The study of the fusion mechanism will hopefully propose optimal experimental conditions for the formation of the super heavy elements.展开更多
基金National Basic Research Program of China(973 Program)(2013CB834404)National Natural Science Foundation of China(11375268,11475263,U1432246,U1432127,11505293,11635015)~~
基金Projects(51072104,51272141)supported by the National Natural Science Foundation of ChinaProject(ts20110828)supported by the Taishan Scholars Project of Shandong Province,ChinaProject(2015AA034404)supported by the Ministry of Science and Technology of China
文摘The surface of AZ91 D magnesium alloy was remelted by plasma beam. The microstructure, composition, hardness, wear and corrosion resistance of the plasma remelted layer（PRL） were characterized. The results show that there is extremely fine and dendrite structure in the PRL at low magnification observation, which is still composed of α-Mg and β-Mg17Al12 phases. But at high magnification observation, the microstructure of the PRL is equiaxial crystalline grains with size of 3-5 μm. And also the content of α-Mg phase decreases while that of β-Mg17Al12 increases and distributes more uniformly in α-Mg matrix compared with the substrate. The hardness of the PRL is much higher than that of the substrate. There are plastic deformation, grains uprooting and tearing evidence with tiny even dimples in the tensile fracture of the PRL, which are different from the substrate. Furthermore, the surface wear and corrosion resistance of AZ91 D are improved significantly after plasma remelting.
文摘So far super heavy elements are synthesized by cold fusion of heavy ions with Pb and Bi targets, or hot fusion reaction using 232Th, 238U and 242>244Pu targets. Further heavier synthesizing could be very difficult. The study of the fusion mechanism will hopefully propose optimal experimental conditions for the formation of the super heavy elements.
