The evolution of microstructure on aging of an （α＋β） titanium alloy （Ti-5A1-5Mo-5V-1Cr-1Fe） in the β and （α＋β） solution-treated and quenched conditions was investigated, The presence of very fine to phase...The evolution of microstructure on aging of an （α＋β） titanium alloy （Ti-5A1-5Mo-5V-1Cr-1Fe） in the β and （α＋β） solution-treated and quenched conditions was investigated, The presence of very fine to phase was detected by electron diffraction for samples aged below 400 ℃. The fine a aggregates are uniformly formed within fl grains by nucleating at the to particles or β/ω interfaces. At higher temperature, the formation of to phase is avoided and the a lamellae are precipitated at the preferred site of grain boundary and then within the matrix. The highest hardness values are found when the alloys are aged at 450 ℃ for fl condition and 350 ℃ for （α＋β） condition.展开更多
Ultrafast electron diffraction （UED） is a rapidly advancing technique capable of recording the atomic-detail structural dynamics in real time. We report the establishment of the first UED system in China. Employing ...Ultrafast electron diffraction （UED） is a rapidly advancing technique capable of recording the atomic-detail structural dynamics in real time. We report the establishment of the first UED system in China. Employing this UED apparatus, both the coherent and the concurrent thermal lattice motions in an aluminium thin-film, trigged by ultrafast laser heating, have been observed. These results demonstrate its ability to directly measure a sub-milli-angstrom lattice spacing change on a sub-picosecond time scale.展开更多
Introduction In the paper the research project ＂Electron crys- tallography study on the structure determination of minute crystals＂ is briefly introduced. （1）Historical background and purpose Here minute crystals ...Introduction In the paper the research project ＂Electron crys- tallography study on the structure determination of minute crystals＂ is briefly introduced. （1）Historical background and purpose Here minute crystals mean the crystals with di- mensions less than 1 micron.展开更多
Hsianghualite (Ca 3 Li 2 [BeSiO 4 ] 3 F 2 , I 2 1 3) is the first new mineral discovered in China in 1958 and is very precious due to its rare occurrence in the Earth. Few studies have reported about hsianghualite dur...Hsianghualite (Ca 3 Li 2 [BeSiO 4 ] 3 F 2 , I 2 1 3) is the first new mineral discovered in China in 1958 and is very precious due to its rare occurrence in the Earth. Few studies have reported about hsianghualite during these years. The authors measured the complex morphology of hsianghualite and found a twin structure in hsianghualite crystal by electron backscattered diffraction (EBSD) technique. The pole figures were used to analyze the twin relationship. The twin law of hsianghualite is the twin plane {110}. This twin law is the same as that proposed by crystallographic theoretic analysis in the previous work. EBSD experi- mental study verified our theoretic analysis of the twin structure in the previous work. The twin structure in hsianghualite has never been reported since the discovery of this mineral in 1958.展开更多
基金Project (50634030) supported by the National Natural Science Foundation of ChinaProject (2007DS04014) supported by the Program of Science and Technology of Shandong Province,ChinaProject supported by the Open Research Fund from the State Key Laboratory of Rolling and Automation,Northeastern University, China
文摘The evolution of microstructure on aging of an （α＋β） titanium alloy （Ti-5A1-5Mo-5V-1Cr-1Fe） in the β and （α＋β） solution-treated and quenched conditions was investigated, The presence of very fine to phase was detected by electron diffraction for samples aged below 400 ℃. The fine a aggregates are uniformly formed within fl grains by nucleating at the to particles or β/ω interfaces. At higher temperature, the formation of to phase is avoided and the a lamellae are precipitated at the preferred site of grain boundary and then within the matrix. The highest hardness values are found when the alloys are aged at 450 ℃ for fl condition and 350 ℃ for （α＋β） condition.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10728409, 10734130, 10735050 and 60621063, and the National Basic Research Programme of China under Grant No 2007CB815102.
文摘Ultrafast electron diffraction （UED） is a rapidly advancing technique capable of recording the atomic-detail structural dynamics in real time. We report the establishment of the first UED system in China. Employing this UED apparatus, both the coherent and the concurrent thermal lattice motions in an aluminium thin-film, trigged by ultrafast laser heating, have been observed. These results demonstrate its ability to directly measure a sub-milli-angstrom lattice spacing change on a sub-picosecond time scale.
文摘Introduction In the paper the research project ＂Electron crys- tallography study on the structure determination of minute crystals＂ is briefly introduced. （1）Historical background and purpose Here minute crystals mean the crystals with di- mensions less than 1 micron.
基金supported by National Natural Science Foundation of China (Grant Nos. 40872040, 40472023)
文摘Hsianghualite (Ca 3 Li 2 [BeSiO 4 ] 3 F 2 , I 2 1 3) is the first new mineral discovered in China in 1958 and is very precious due to its rare occurrence in the Earth. Few studies have reported about hsianghualite during these years. The authors measured the complex morphology of hsianghualite and found a twin structure in hsianghualite crystal by electron backscattered diffraction (EBSD) technique. The pole figures were used to analyze the twin relationship. The twin law of hsianghualite is the twin plane {110}. This twin law is the same as that proposed by crystallographic theoretic analysis in the previous work. EBSD experi- mental study verified our theoretic analysis of the twin structure in the previous work. The twin structure in hsianghualite has never been reported since the discovery of this mineral in 1958.
