In order to study the effect of intermaetallics on the corrosion behaviour of 7A52 aluminum alloy, the alloy was characterized by means of SEM-EDS and scanning Kelvin probe force microscopy(SKPFM). The experimental ...In order to study the effect of intermaetallics on the corrosion behaviour of 7A52 aluminum alloy, the alloy was characterized by means of SEM-EDS and scanning Kelvin probe force microscopy(SKPFM). The experimental results indicate that there are two different intermetallics:A1-Mn-Fe and Mg2Si. Both intermetallics exhibite the negative volta potential relative to the matrix indicating an anodic behaviour. Hereby, they are easy to be dissolved and corroded under the erosive environment, and there become the corrosion initiation sites. The A1-Mn-Fe intermetallics show stronger anodic behaviour than those of Mg2Si intermetalics. It means that A1-Mn-Fe intermetalics are easier to be corroded.展开更多
Alloying elements, present in the aluminum solid solution or the precipitates, influence the corrosion resistance of A1-Mg-Mn-Zn alloys. In this study, sensi- tizing treatment was applied to an A1-Mg-Mn-Zn alloy to mo...Alloying elements, present in the aluminum solid solution or the precipitates, influence the corrosion resistance of A1-Mg-Mn-Zn alloys. In this study, sensi- tizing treatment was applied to an A1-Mg-Mn-Zn alloy to modify the precipitation at the grain boundaries or in the grains. Transmission electron microscopy (TEM) and scanning electron microscope (SEM) were used to characterize various second-phase particles and determine their orientation relationship with the A1 matrix. After sensitizing treatment, z-phase (Mg32(Al, Zn)49) is observed to precipitate along the grain boundaries in a coarser size, producing a discontinuous grain boundary precipitate structure. In addition, Mn-rich particles are found to form with various shapes, such as global, plate and rhombus.展开更多
基金Funded by the National Natural Science Foundation of China(No.50801066)
文摘In order to study the effect of intermaetallics on the corrosion behaviour of 7A52 aluminum alloy, the alloy was characterized by means of SEM-EDS and scanning Kelvin probe force microscopy(SKPFM). The experimental results indicate that there are two different intermetallics:A1-Mn-Fe and Mg2Si. Both intermetallics exhibite the negative volta potential relative to the matrix indicating an anodic behaviour. Hereby, they are easy to be dissolved and corroded under the erosive environment, and there become the corrosion initiation sites. The A1-Mn-Fe intermetallics show stronger anodic behaviour than those of Mg2Si intermetalics. It means that A1-Mn-Fe intermetalics are easier to be corroded.
基金financially supported by the National Natural Science Foundation of China (No.51301017)the Common Construction Project from Beijing Municipal Commission of Education
文摘Alloying elements, present in the aluminum solid solution or the precipitates, influence the corrosion resistance of A1-Mg-Mn-Zn alloys. In this study, sensi- tizing treatment was applied to an A1-Mg-Mn-Zn alloy to modify the precipitation at the grain boundaries or in the grains. Transmission electron microscopy (TEM) and scanning electron microscope (SEM) were used to characterize various second-phase particles and determine their orientation relationship with the A1 matrix. After sensitizing treatment, z-phase (Mg32(Al, Zn)49) is observed to precipitate along the grain boundaries in a coarser size, producing a discontinuous grain boundary precipitate structure. In addition, Mn-rich particles are found to form with various shapes, such as global, plate and rhombus.