Browsing by Author "Duh, Jenq-Gong"

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Mechanical and tribological properties evaluation of cathodic arc deposited CrN/ZrN multilayer coatings
(2011-12-25)
Huang, Sung-Hsiu
;
Chen, Siao-Fan
;
Kuo, Yu-Chu
;
Wang, Chaur-Jeng
;
Lee, Jyh-Wei
Five nanostructured CrN/ZrN multilayer coatings were deposited periodically by cathodic arc evaporation. The bilayer periods of the CrN/ZrN multilayer coatings were controlled in the range of 5 to 30 nm. The structures and bilayer period of the multilayer coatings were characterized by an X-ray diffractometer. The microstructures of thin films were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. Nanoindentation, scratch tests, Daimler-Benz Rockwell-C (HRC-DB) adhesion tests, microhardness and pin-on-disk wear tests were used to evaluate the hardness, adhesion, indentation toughness and tribological properties of thin films, respectively. It was found that the hardness and tribological properties were strongly influenced by the bilayer period of the CrN/ZrN multilayer coatings. An optimal combination of mechanical properties and excellent tribological behavior was found for a coating with a critical bilayer period of 30 nm. (C) 2011 Elsevier B.V. All rights reserved.
Self-carbonized lamellar nano/micro hierarchical structure C/TiO2 and its Li-ion intercalation performance
(2012)
Chen, Po-Chin
;
Tsai, Min-Chiao
;
Chen, Huang-Chin
;
Lin, I-Nan
;
Sheu, Hwo-Shuenn
In this study, two new layered titanates, fibrillar TiO2 center dot(CH3COOH)(1.4) and chrysanthemum-like TiO2 center dot(CH3COOH)(0.9) (named as FT and CT) with acetic acid and acetate intercalation have been synthesized by reacting titanium isopropoxide (TTIP) with acetic acid at different temperatures. Furthermore, nano/micro hierarchical structure TiO2 with high TiO2-B/anatse ratio was obtained by annealing the titanate (CT). For use as an anode for lithium ion batteries, uniform carbon coated titanium dioxide with high TiO2-B content was obtained by "self-carbonizing'' CT under argon atmosphere at 350 degrees C, and the compound was named SC-CT350. The capacity of the anode made from SC-CT350 can reach 144 mA h g(-1) under a high charging/discharging rate (10 C) and showed excellent retention ability.
The effect of Cr/Zr chemical composition ratios on the mechanical properties of CrN/ZrN multilayered coatings deposited by cathodic arc deposition system
(2013-09-01)
Chen, Siao-Fan
;
Kuo, Yu-Chu
;
Wang, Chaur-Jeng
;
Huang, Sung-Hsiu
;
Lee, Jyh-Wei
CrN/ZrN multilayer coatings with various Cr/Zr chemical compositions ratio were fabricated by a cathode arc deposition system. The Cr/Zr atomic ratios of the CrN/ZrN multilayer coatings were controlled, ranging from I to 2.5. The chemical composition of CrN/ZrN multilayer thin films was determined by a field emission electron probe microanalyzer (FE-EPMA). The phase composition of multilayer coatings was analyzed by a glancing angle X-ray diffractometer. Microstructures of the thin films were examined by field emission scanning electron microscopy (FE-SEM). Nanoindentation, the Daimler Benz Rockwell-C (HRC-DB) adhesion, microhardness, pin-on-disc wear tests and scratch tests were used to evaluate the hardness, adhesion, toughness and tribological properties of the thin films, respectively. It was found that the hardness and tribological properties were strongly influenced by the Cr/Zr chemical composition ratios of the CrN/ZrN multilayer coatings. Optimal mechanical properties and the maximum hardness of 28 GPa were achieved for the coating when the Cr/Zr atomic ratio was 2.1. (C) 2012 Elsevier B.V. All rights reserved.
The investigation of interfacial and crystallographic observation in the Ni(V)/SAC/OSP Cu solder joints with high and low silver content during thermal cycling test
(2015-12-01)
Lee, Christine Jill
;
Chen, Wei-Yu
;
Chou, Tzu-Ting
;
Lee, Tae-Kyu
;
Wu, Yew-Chung
This study investigated the microstructure and grain orientation of Ni(V)/SAC396/OSP Cu and Ni(V)/SAC105/OSP Cu solder joints during thermal cycling test (TCT). In general, adjusting Ag content in solders influenced the performance of thermal cycling (TC). Nevertheless, it is still crucial to find the optimal condition of Ag and related mechanisms of crack formation during TCT. This study applied FE-SEM to observe the crack propagation and the precipitation of Sn-Ag IMCs in the solders. Moreover, FE-EPMA and EBSD were used to detect the elemental distribution and grain orientation near the cracks, respectively. The locations of crack initiation are strongly related to the CTE mismatch between Si chip and solder alloy. Besides, the large number of Ag3Sn precipitations in the joint with high Ag content efficiently hinder the crack propagation due to the effects of precipitation hardening. It is revealed that the Ni(V)/SAC396/OSP Cu exhibits good thermal stability during thermal cycle test.