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
The experiment was carried out in a private orchard situated at Atrush town, Duhok Govemorate Kurdistan Region-Iraq during 2011 season to study the effect of foliar application of three concentrations of potassium （0...The experiment was carried out in a private orchard situated at Atrush town, Duhok Govemorate Kurdistan Region-Iraq during 2011 season to study the effect of foliar application of three concentrations of potassium （0.0%, 0.5% and 1%） and three concentrations of copper （0.0%, 0.02% and 0.04%） on an eight years old peach cultivar, planted in clay soil, spaced at 4.0 m x 4.0 m. The foliar application was done twice, on April 24, 2011 and May 25, 2011. The results showed that spraying of potassium at both concentration （0.5% and 1%） or copper at high concentration （0.04%） had a positive effect on leaf area, leaf fresh weight, leaf dry weight, total chlorophyll, fruit weight, fruit number and yield per tree as well as fruit diameter, pith thick, pulp weight, seed weight and total soluble solid. The interaction between potassium and copper significantly enhanced all detected traits, since trees receiving 1% and sprayed with 0.04% of copper was characterized by the highest values of all growth and yield characteristics compared to the lowest values at untreated trees （control）.展开更多
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The experiment was carried out in a private orchard situated at Atrush town, Duhok Govemorate Kurdistan Region-Iraq during 2011 season to study the effect of foliar application of three concentrations of potassium （0.0%, 0.5% and 1%） and three concentrations of copper （0.0%, 0.02% and 0.04%） on an eight years old peach cultivar, planted in clay soil, spaced at 4.0 m x 4.0 m. The foliar application was done twice, on April 24, 2011 and May 25, 2011. The results showed that spraying of potassium at both concentration （0.5% and 1%） or copper at high concentration （0.04%） had a positive effect on leaf area, leaf fresh weight, leaf dry weight, total chlorophyll, fruit weight, fruit number and yield per tree as well as fruit diameter, pith thick, pulp weight, seed weight and total soluble solid. The interaction between potassium and copper significantly enhanced all detected traits, since trees receiving 1% and sprayed with 0.04% of copper was characterized by the highest values of all growth and yield characteristics compared to the lowest values at untreated trees （control）.
