Browsing by Author "Chen, Shih Hsun"

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Enhanced electromagnetic properties of Fe-Cr-Si alloy powders by sodium silicate treatment
(2015-07-15)
Chen, Shih Fan
;
Chang, Hsuan Yao
;
Wang, Shea Jue
;
Chen, Shih Hsun
;
Chen, Chien Chon
The Fe-Si-Cr alloy powders were successfully modified by using the phosphatizing and sodium silicate coating processes. The optimized surface pre-treatment for Fe-Si-Cr powder was phosphatized in 2 wt.% phosphoric solution and further treated with 4 wt.% sodium silicate solution at 75 degrees C for 30 min. These treatments increased the high-frequency stability for Fe-Si-Cr alloy powders, and the annealed cores further showed the enhanced performance of permeability, impedance, quality factor and anti-corrosion ability. Comparing with the Fe-Si-Al alloy, the Fe-Si-Cr also showed a superior performance in density, moldability and saturated magnetic induction. (C) 2015 Elsevier B.V. All rights reserved.
Influence of annealing treatment on soft magnetic properties of Fe76Si10B10Cr2Y2 amorphous ribbon
(2015-04-05)
Chen, Shih Fan
;
Hung, Chi Yu
;
Wang, Shea Jue
;
Chen, Shih Hsun
;
Chen, Chien Chon
In this study, the influence of annealing treatment on soft magnetic properties of Fe76Si10B10Cr2Y2 amorphous ribbon was investigated. Alloy ribbons were synthesized by the single roller melt-spinning method. The magnetic measurements of the as-cast ribbon were inspected, including M-s, H-c and T-c. The value of Ms was 1.25 T, H-c was 22.84 A/m and T-c was 564.4 K. The soft magnetic properties of the optimum parameter for the annealing temperature and annealing time was at 500 degrees C for 3 min, M-s was 1.37 T and H-c was 1.11 A/m. Therefore, the soft magnetic properties of the Fe76Si10B10Cr2Y2 alloy ribbon was significantly improved through the annealing treatment. (C) 2015 Published by Elsevier B.V.
Novel morphology and solidification behavior of eutectic bismuth-tin (Bi-Sn) nanowires
(2009-07-29)
Chen, Shih Hsun
;
Chen, Chien Chon
;
Chao, Chuen Guang
;
材料科學與工程學系
;
Department of Materials Science and Engineering
In the present work we show a simple and robust fabrication process for dense and continuous bismuth-tin (Bi-Sn) eutectic nanowires. The Bi-Sn eutectic nanowires of 200 nm diameter and several tens of mu m, in length were fabricated by a vacuum hydraulic force method. The alloy melt was injected into an anodic aluminum oxide (AAO) template to form nanowires after melt solidification. For this process, nanowires were formed from non-atomic deposition with liquid alloy; in this way, the composition of nanowires can be controlled precisely in stoichiometry. The Bi-Sn melt was restricted inside the AAO which has a low thermo-conduction and long period cooling rate around the melt. On the other hand, the heat flow is along the tube Z-axis and the melt is solidified from the AAO bottom to top because of the open pore on the AAO top. The eutectic nanowires were found to be dense and continuous with a uniform diameter throughout the length of the wires and with a lamellar microstructure along the wires' Z-axis. In addition, the alternative segmental compositions showed that the ratio of tin to bismuth is approximately 33:1. (C) 2009 Elsevier B.V. All rights reserved.