Weimin MAO
,
Heng JIANG
,
Ping YANG
,
Huiping FENG
,
Yongning YU
材料科学技术（英文）
The distribution of microelement Fe, Si, Cu and Mg in the surface layer of aluminum foil annealed at 300℃ and 500℃ were determined by secondary ion mass spectrometer. The corrosion structure produced by electrochemical etching was also observed. It was found that the Mg concentration at external surface was increased exponentially over the fourth degree and promoted by higher annealing temperature, which will increase the number of corrosion pits inside the large grains, and therefore the specific capacity of the foils for electrolytic capacitors. The similar effects of microelement Fe, Si and Cu were not so strong.
关键词:
Electrolytic capacitor
,
null
,
null
,
null
Weimin MAO
,
Yongning YU
,
Hong YANG and Bo SONG (Dept. of Materials Science and Engineering
,
University of Science and Technology Beijing
,
Beijing 100083
,
China)
材料科学技术（英文）
The texture evaluation of α2 phase in Ti-25Al-10Nb-3V-1Mo sheet during rolling and annealing has been investigated by means of microstructure observation and ODF analysis. From the weak initial {1010} (1210) and {0001}(1210) textures a {1210}(1010) texture and a {0001}(uvtw)fibre texture are formed after cold rolling. The {0001} (1210) texture is also strengthened simultaneously. The activation process of slip systems is discussed concerning formation of the rolling texture. Because of the disappearance of {0001} (nvtw) fibre texture the primary recrystallization process should occur and the {1210}(1010) texture forms during annealing
关键词:
Leng CHEN
,
Weimin MAO
,
Yongning YU
,
Huiping FENG
材料科学技术（英文）
An X-ray diffractometer that equipped with a two-dimensional detector is used for developing the technique of grain size measurement for strong textured and coarse-grained Si steel sheet. The method is based on the concept that the position of diffraction spots depends on the orientation of individual grains. The two-dimensional detector has the ability to collect abundant diffraction information in seconds, thus it can be determined rapidly and accurately whether a series of diffraction spots come from the same grain. The experimental results show that this method can be used for measuring grain size and its distribution in strong textured and coarse-grained metal sheets.
关键词:
Grain size
,
null
,
null
Guohui ZHU
,
Weimin MAO
,
Yongning YU
材料科学技术（英文）
The orientation distribution of recrystallization grains formed during annealing, as well as their misorientation relationship to the deformation matrix in cold rolled FeCo alloy have been investigated. It was found that most of the recrystallization nuclei were located near the boundary area with rather random orientations, and their misorientation angles to the deformation matrix were generally very high. However a few nuclei were also observed inside the deformation grains, to which they had very similar orientations. Therefore the misorientation angles between the nuclei and the deformation matrix were generally very low. The orientation and the misorientation distributions of the nuclei have very strong influence on the recrystallization process which could result in a very weak recrystallization texture. The corresponding mechanism is discussed.
关键词:
