The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
Chin-guo Kuo - One of the best experts on this subject based on the ideXlab platform.
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Fabrication and Characterization of a Pb-Sn Nanowire Array for Detecting Carbon Monoxide.
Journal of nanoscience and nanotechnology, 2016Co-Authors: Chin-guo Kuo, Ho Chang, Guo Yan LiuAbstract:In this study, a Pb-Sn alloy nanowire of 80 nm in diameter and 50 microm in length is obtained by an anodic aluminum oxide nanomold and Vacuum Die Casting method. The upper and lower ends of the prepared Pb-Sn alloy nanowire array are vapor deposited with 3 microm of copper thin film, which serves as the conductive layer of the gas sensor. Experimental results show that the sensitivities of 3 gas sensors fabricated by 3 different Sn-Pb alloy nanowire arrays, namely Sn70%-Pb 30% wt, Sn63%-Pb 37% wt and Sn50%-Pb 50% wt, for detecting a carbon monoxide concentration of 500 ppm under a working temperature of 250 degrees C, were 17.83%, 14.89% and 14.12% respectively.
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Fabrication of ZnO nanowires arrays by anodization and high-Vacuum Die Casting technique, and their piezoelectric properties
Sensors (Switzerland), 2016Co-Authors: Chin-guo Kuo, Ho Chang, Jian Hao WangAbstract:In this investigation, anodic aluminum oxide (AAO) with arrayed and regularly arranged nanopores is used as a template in the high-Vacuum Die Casting of molten zinc metal (Zn) into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO) nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA.
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Fabrication of a Zinc Aluminum Oxide Nanowire Array Photoelectrode for a Solar Cell Using a High Vacuum Die Casting Technique
International Journal of Photoenergy, 2014Co-Authors: Chin-guo Kuo, Jung Hsuan Chen, Yueh Han LiuAbstract:Zinc aluminum alloy nanowire was fabricated by the Vacuum Die Casting. Zinc aluminum alloy was melted, injected into nanomold under a hydraulic pressure, and solidified as nanowire shape. Nanomold was prepared by etching aluminum sheet with a purity of 99.7 wt.% in oxalic acid solution. A nanochannel within nanomold had a pore diameter of 80 nm and a thickness of 40 μm. Microstructure and characteristic analysis of the alumina nanomold and zinc-aluminum nanowire were performed by scanning electron microscope, X-ray diffraction analysis, and energy dispersive X-ray spectroscopy. Zinc aluminum oxide nanowire array was produced using the thermal oxidation method and designed for the photoelectrode application.
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Fabrication of a Miniature Zinc Aluminum Oxide Nanowire Array Gas Sensor and Application for Environmental Monitoring
International Journal of Photoenergy, 2014Co-Authors: Chin-guo Kuo, Jung Hsuan Chen, Chi-wu Huang, Yueh Han LiuAbstract:A miniature n-type semiconductor gas sensor was fabricated successfully using zinc aluminum oxide nanowire array and applied to sense oxygen. The present study provided a novel method to produce zinc aluminum alloy nanowire 80 nm in diameter by the Vacuum Die Casting technique and then obtain zinc aluminum oxide nanowire array using the thermal oxidation technique. The gas sensing properties were evaluated through the change of the sensitivity. The factors influencing the sensitivity of the gas sensor, such as the alloy composition, operating temperature, and oxygen concentration, were investigated further. Experimental results indicated that the maximum sensitivity could be acquired when the weight percentage of aluminum was 5% in zinc aluminum alloy at the operating temperature of200°C.
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Fabrication of a Pb-Sn nanowire array gas sensor using a novel high Vacuum Die Casting technique
Electronic Materials Letters, 2013Co-Authors: Chin-guo Kuo, Ho Chang, Guo Yan Liu, Lih-ren Hwang, Shu Hor, Jia-shin Chen, Sheng-cheng ChengAbstract:In this study, an anodic aluminum oxide nanomold was obtained by etching on an aluminum substrate at a purity of 99.7% with an oxalic acid electrolyte. After etching, a nanomold was prepared with pores that were measured at 80 nm in diameter. This nanomold was used as a base. Using the Vacuum Casting method, the Pb-Sn alloy was Die-cast into the nanomold and consequently shaped into a Pb-Sn alloy nanowire of 80 nm in diameter and 50 µm in length. After solidification, a Pb-Sn nanowire array was obtained. The array of Pb-Sn nanowires prepared in this study can be applied to a gas sensor. Microstructural analysis of the AAO nanomold and the Pb-Sn nanowire array are performed by SEM and XRD.
Sheng-cheng Cheng - One of the best experts on this subject based on the ideXlab platform.
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Fabrication of a Pb-Sn nanowire array gas sensor using a novel high Vacuum Die Casting technique
Electronic Materials Letters, 2013Co-Authors: Chin-guo Kuo, Ho Chang, Guo Yan Liu, Lih-ren Hwang, Shu Hor, Jia-shin Chen, Sheng-cheng ChengAbstract:In this study, an anodic aluminum oxide nanomold was obtained by etching on an aluminum substrate at a purity of 99.7% with an oxalic acid electrolyte. After etching, a nanomold was prepared with pores that were measured at 80 nm in diameter. This nanomold was used as a base. Using the Vacuum Casting method, the Pb-Sn alloy was Die-cast into the nanomold and consequently shaped into a Pb-Sn alloy nanowire of 80 nm in diameter and 50 µm in length. After solidification, a Pb-Sn nanowire array was obtained. The array of Pb-Sn nanowires prepared in this study can be applied to a gas sensor. Microstructural analysis of the AAO nanomold and the Pb-Sn nanowire array are performed by SEM and XRD.
Alan A Luo - One of the best experts on this subject based on the ideXlab platform.
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Microstructure and Mechanical Properties of High Pressure Die Cast Mg–Al–Sn–Si Alloys
The Minerals Metals & Materials Series, 2017Co-Authors: Andrew D. Klarner, Weihua Sun, Jiashi Miao, Alan A LuoAbstract:The effect of a small addition of silicon (Si) was stuDied to increase the mechanical properties of Mg–Al–Sn alloys. Test specimens were produced by a Vacuum Die Casting process which makes it possible to perform various heat treatments on the alloy which was not possible with conventional high pressure Die Casting (HPDC). The addition of Si leads to the formation of a binary Mg2Si phase which contributes to an increase in strength in the as-cast condition. Artificial aging treatments were performed to further increase the strength of the alloys by precipitation of fine Mg2Sn, Mg2Si, and Mg17Al12 phases. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) techniques were used to observe these fine precipitates at different stages of the heat treatment and mechanical testing was performed to compare strength and ductility to previous magnesium alloys.
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Microstructure and Mechanical Properties of Mg-7Al-2Sn Alloy Processed by Super Vacuum Die-Casting
Metallurgical and Materials Transactions A, 2013Co-Authors: Xiaoying Shi, Alan A Luo, Xiaoqin Zeng, Wenjiang DingAbstract:The microstructural evolution of Mg-7Al-2Sn (AT72) alloy processed by super Vacuum Die-Casting and heat treated at various conditions was stuDied. The results showed that the dendritic microstructure in the as-cast AT72 alloy consisted of α-Mg, Mg2Sn, and Mg17Al12 phases. After solution treatment at temperatures ranging from 663 K to 703 K (390 °C to 430 °C), the Mg17Al12 phase dissolved into the Mg matrix entirely, while the Mg2Sn phase partially dissolved into matrix. An average grain size of about 40 μm in the alloy could be achieved after solution treatment at 683 K (410 °C) for 16 hours. A large amount of lath-shaped precipitates of Mg2Sn and Mg17Al12 was observed in the aged AT72 alloy. The results of tensile property evaluation at room temperature showed that the ductility of the solution-treated alloy was dramatically improved, in comparison with the as-cast alloy. In the peak aged condition, the tensile strength of the alloy was increased, which was attributed to the deposition of fine Mg17Al12 and Mg2Sn precipitates during the aging treatment.
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Magnesium Casting technology for structural applications
Journal of Magnesium and Alloys, 2013Co-Authors: Alan A LuoAbstract:This paper summarizes the melting and Casting processes for magnesium alloys. It also reviews the historical development of magnesium Castings and their structural uses in the western world since 1921 when Dow began producing magnesium pistons. Magnesium Casting technology was well developed during and after World War II, both in gravity sand and permanent mold Casting as well as high-pressure Die Casting, for aerospace, defense and automotive applications. In the last 20 years, most of the development has been focused on thin-wall Die Casting applications in the automotive industry, taking advantages of the excellent castability of modern magnesium alloys. Recently, the continued expansion of magnesium Casting applications into automotive, defense, aerospace, electronics and power tools has led to the diversification of Casting processes into Vacuum Die Casting, low-pressure Die Casting, squeeze Casting, lost foam Casting, ablation Casting as well as semi-solid Casting. This paper will also review the historical, current and potential structural use of magnesium with a focus on automotive applications. The technical challenges of magnesium structural applications are also discussed. Increasing worldwide energy demand, environment protection and government regulations will stimulate more applications of lightweight magnesium Castings in the next few decades. The development of use of Integrated Computational Materials Engineering (ICME) tools will accelerate the applications of magnesium Castings in structural applications.
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Improved bending fatigue and corrosion properties of a Mg–Al–Mn alloy by super Vacuum Die Casting
Scripta Materialia, 2012Co-Authors: Wei Wen, Alan A Luo, Tongguang Zhai, Yan Jin, Yang-tse Cheng, Ilona HoffmannAbstract:This paper shows significantly improved mechanical properties (∼64% higher bending fatigue strength) and corrosion resistance (39–62% lower corrosion rate) in a Mg–6Al–0.3Mn alloy (AM60B) produced by a new super Vacuum Die Casting (SVDC) process compared with the conventional high-pressure Die Casting (HPDC). The SVDC samples exhibited a skin layer which contained 6–12% more eutectic phase and was ∼14% harder than those of the HPDC material, due to faster cooling rates in the SVDC process resulting from better Die–metal contact.
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Advanced Casting technologies for lightweight automotive applications
China Foundry, 2010Co-Authors: Alan A Luo, Anil K Sachdev, Bob R. PowellAbstract:This paper provides an overview of alloy and process developments in aluminum and magnesium Castings for lightweight automotive applications. Wear-resistant aluminum alloys, creep-resistant and high strength/ductility magnesium alloys have been developed for automotive applications. On the process front, Vacuum-assisted Die Casting and high Vacuum Die Casting technologies have been developed for high-integrity body and chassis applications. Thin-wall and hollow Casting components are being produced by low-pressure Die Casting processes for structural applications. OverCasting technology is gaining traction and has enabled mixed material designs for automotive sub-systems such as engine cradles and instrument panel beams. Simulation tools developed to predict the interfacial interactions of the dissimilar components and the structural integrity of the overcast systems are being validated in the Casting trials.
Ho Chang - One of the best experts on this subject based on the ideXlab platform.
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Fabrication and Characterization of a Pb-Sn Nanowire Array for Detecting Carbon Monoxide.
Journal of nanoscience and nanotechnology, 2016Co-Authors: Chin-guo Kuo, Ho Chang, Guo Yan LiuAbstract:In this study, a Pb-Sn alloy nanowire of 80 nm in diameter and 50 microm in length is obtained by an anodic aluminum oxide nanomold and Vacuum Die Casting method. The upper and lower ends of the prepared Pb-Sn alloy nanowire array are vapor deposited with 3 microm of copper thin film, which serves as the conductive layer of the gas sensor. Experimental results show that the sensitivities of 3 gas sensors fabricated by 3 different Sn-Pb alloy nanowire arrays, namely Sn70%-Pb 30% wt, Sn63%-Pb 37% wt and Sn50%-Pb 50% wt, for detecting a carbon monoxide concentration of 500 ppm under a working temperature of 250 degrees C, were 17.83%, 14.89% and 14.12% respectively.
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Fabrication of ZnO nanowires arrays by anodization and high-Vacuum Die Casting technique, and their piezoelectric properties
Sensors (Switzerland), 2016Co-Authors: Chin-guo Kuo, Ho Chang, Jian Hao WangAbstract:In this investigation, anodic aluminum oxide (AAO) with arrayed and regularly arranged nanopores is used as a template in the high-Vacuum Die Casting of molten zinc metal (Zn) into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO) nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA.
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Fabrication of a Pb-Sn nanowire array gas sensor using a novel high Vacuum Die Casting technique
Electronic Materials Letters, 2013Co-Authors: Chin-guo Kuo, Ho Chang, Guo Yan Liu, Lih-ren Hwang, Shu Hor, Jia-shin Chen, Sheng-cheng ChengAbstract:In this study, an anodic aluminum oxide nanomold was obtained by etching on an aluminum substrate at a purity of 99.7% with an oxalic acid electrolyte. After etching, a nanomold was prepared with pores that were measured at 80 nm in diameter. This nanomold was used as a base. Using the Vacuum Casting method, the Pb-Sn alloy was Die-cast into the nanomold and consequently shaped into a Pb-Sn alloy nanowire of 80 nm in diameter and 50 µm in length. After solidification, a Pb-Sn nanowire array was obtained. The array of Pb-Sn nanowires prepared in this study can be applied to a gas sensor. Microstructural analysis of the AAO nanomold and the Pb-Sn nanowire array are performed by SEM and XRD.
Guo Yan Liu - One of the best experts on this subject based on the ideXlab platform.
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Fabrication and Characterization of a Pb-Sn Nanowire Array for Detecting Carbon Monoxide.
Journal of nanoscience and nanotechnology, 2016Co-Authors: Chin-guo Kuo, Ho Chang, Guo Yan LiuAbstract:In this study, a Pb-Sn alloy nanowire of 80 nm in diameter and 50 microm in length is obtained by an anodic aluminum oxide nanomold and Vacuum Die Casting method. The upper and lower ends of the prepared Pb-Sn alloy nanowire array are vapor deposited with 3 microm of copper thin film, which serves as the conductive layer of the gas sensor. Experimental results show that the sensitivities of 3 gas sensors fabricated by 3 different Sn-Pb alloy nanowire arrays, namely Sn70%-Pb 30% wt, Sn63%-Pb 37% wt and Sn50%-Pb 50% wt, for detecting a carbon monoxide concentration of 500 ppm under a working temperature of 250 degrees C, were 17.83%, 14.89% and 14.12% respectively.
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Fabrication of a Pb-Sn nanowire array gas sensor using a novel high Vacuum Die Casting technique
Electronic Materials Letters, 2013Co-Authors: Chin-guo Kuo, Ho Chang, Guo Yan Liu, Lih-ren Hwang, Shu Hor, Jia-shin Chen, Sheng-cheng ChengAbstract:In this study, an anodic aluminum oxide nanomold was obtained by etching on an aluminum substrate at a purity of 99.7% with an oxalic acid electrolyte. After etching, a nanomold was prepared with pores that were measured at 80 nm in diameter. This nanomold was used as a base. Using the Vacuum Casting method, the Pb-Sn alloy was Die-cast into the nanomold and consequently shaped into a Pb-Sn alloy nanowire of 80 nm in diameter and 50 µm in length. After solidification, a Pb-Sn nanowire array was obtained. The array of Pb-Sn nanowires prepared in this study can be applied to a gas sensor. Microstructural analysis of the AAO nanomold and the Pb-Sn nanowire array are performed by SEM and XRD.
