The erosion behavior of a nanocomposite W-Cu material under arc breakdown was investigated. The arc erosion rates of the material were determined, and the eroded surfaces and arc erosion mechanisms were studied by sca...The erosion behavior of a nanocomposite W-Cu material under arc breakdown was investigated. The arc erosion rates of the material were determined, and the eroded surfaces and arc erosion mechanisms were studied by scanning eleclion microscopy. It is concluded that the nanocomposite W-Cu electrical contact material shows a characteristic of spreading arcs. The arc breakdown of a commercially used W-Cu alloy was limited in a few areas, and its average arc erosion rate is twice as large as that of the former. Furthermore, it is also proved that the arc extinction ability and arc stability of the nanocomposite W-Cu material are excellent, and melting is the major failure modality in the make-and-break operation of arcs.展开更多
The spherical silver mirco/nano-particles with narrow size distributions were obtained by chemical reduction of silver ammonia solution with ascorbic acid as reducing agent and bovine serum albumin (BSA) as bio-templa...The spherical silver mirco/nano-particles with narrow size distributions were obtained by chemical reduction of silver ammonia solution with ascorbic acid as reducing agent and bovine serum albumin (BSA) as bio-template. The effects of the concentration of Ag+ ions, BSA and ammonia, reactive temperature on the silver morphology and particle sizes were investigated. SEM, TEM and XRD were employed to characterize the morphology and structures of the prepared silver mirco/nano-particles. The results show that the spherical silver particle with smooth surface and narrow size distributions can be obtained by controlling the concentration of Ag+ ions, BSA, reaction temperature, etc. By controlling the above parameters, the silver spherical mirco/nano-particles with particle sizes ranging from 0.2 to 2.3 m can be well prepared, which is expected to be used in manufacturing high performance electronic pastes.展开更多
基金This work was financially supported by the National Natural Science Foundation of China (No. 50071043) the Natural Science Foundation ofShaanxi Province, China (No. 2004E105).
文摘The erosion behavior of a nanocomposite W-Cu material under arc breakdown was investigated. The arc erosion rates of the material were determined, and the eroded surfaces and arc erosion mechanisms were studied by scanning eleclion microscopy. It is concluded that the nanocomposite W-Cu electrical contact material shows a characteristic of spreading arcs. The arc breakdown of a commercially used W-Cu alloy was limited in a few areas, and its average arc erosion rate is twice as large as that of the former. Furthermore, it is also proved that the arc extinction ability and arc stability of the nanocomposite W-Cu material are excellent, and melting is the major failure modality in the make-and-break operation of arcs.
基金supported by the National Natural Science Foundation of China (Grant No. 51271135) "New Century Talents Project" of Ministry of Education and Fundamental Research funding of Xi'an Jiaotong Universitythe project of Innovative Team of Shaanxi Province (Grant No. 2013KCT-05)
文摘The spherical silver mirco/nano-particles with narrow size distributions were obtained by chemical reduction of silver ammonia solution with ascorbic acid as reducing agent and bovine serum albumin (BSA) as bio-template. The effects of the concentration of Ag+ ions, BSA and ammonia, reactive temperature on the silver morphology and particle sizes were investigated. SEM, TEM and XRD were employed to characterize the morphology and structures of the prepared silver mirco/nano-particles. The results show that the spherical silver particle with smooth surface and narrow size distributions can be obtained by controlling the concentration of Ag+ ions, BSA, reaction temperature, etc. By controlling the above parameters, the silver spherical mirco/nano-particles with particle sizes ranging from 0.2 to 2.3 m can be well prepared, which is expected to be used in manufacturing high performance electronic pastes.
