The Experts below are selected from a list of 2547 Experts worldwide ranked by ideXlab platform
Mikio Fukuhara - One of the best experts on this subject based on the ideXlab platform.
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Dealloying of Cu–Zr–Ti bulk metallic glass in Hydrofluoric Acid Solution
2020Co-Authors: Hiroya Abe, Kazuyoshi Sato, Hiroshi Nishikawa, Tadashi Takemoto, Mikio FukuharaAbstract:The dealloying behavior of Cu 60 Zr 30 Ti 10 metallic glass was investigated under free corrosion conditions using Hydrofluoric Acid (HF) Solutions at room temperature. After immersing in HF Solutions with various concentrations (0.05, 0.1, 0.5 and 1 M) for 300 s, color of all samples changed to be pinkish or peachy, which was ascribed to Cu based on the XRD patterns. According to the SEM-EDS study, HF immersion selectively leached the Zr and Ti elements, leaving Cu behind. Increasing the HF concentration increased the dealloying rate. Moreover, the HF concentration strongly influenced the surface morphology of the resulting Cu
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enhancement of solderability of cu60zr30ti10 bulk metallic glass by dealloying in Hydrofluoric Acid Solution
Quarterly Journal of The Japan Welding Society, 2011Co-Authors: Takehiro Naoi, Hiroshi Nishikawa, Tadashi Takemoto, Mikio Fukuhara, Akihisa InoueAbstract:To extend the engineering applications of bulk metallic glasses (BMGs), it is necessary to create process to form appropriate BMG/BMG and BMG/crystalline metal joint. In this study, Hydrofluoric Acid (HF) Solution treatment and a laser soldering process were employed to enhance the solderability of Cu60Zr30Ti10 BMG. The surface treatment in HF Solution successfully dissolved surface Zr and Ti, resulting in concentration of Cu at the surface. A reflow soldering process using Sn-3.0 mass% Ag-0.5 mass% Cu (SAC) solder on this surface showed obvious dewetting because the thin Cu-rich layer dissolved into the molten solder. Laser soldering with a 0.01 s irradiation time, which produces rapid heating and cooling rates, offered good wettability of SAC solder and Sn-57 mass% Bi (SB) solder. At the interface between the SB solder and the HF-treated BMG foil, an intermetallic compound (IMC) layer was observed by scanning electron microscopy (SEM).
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dealloying of cu zr ti bulk metallic glass in Hydrofluoric Acid Solution
Materials Transactions, 2009Co-Authors: Hiroya Abe, Kazuyoshi Sato, Hiroshi Nishikawa, Tadashi Takemoto, Mikio FukuharaAbstract:metallic glass was investigated under free corrosion conditions using hydrofluoric Acid (HF)Solutions at room temperature. After immersing in HF Solutions with various concentrations (0.05, 0.1, 0.5 and 1M) for 300s, color of allsamples changed to be pinkish or peachy, which was ascribed to Cu based on the XRD patterns. According to the SEM-EDS study, HFimmersion selectively leached the Zr and Ti elements, leaving Cu behind. Increasing the HF concentration increased the dealloying rate.Moreover, the HF concentration strongly influenced the surface morphology of the resulting Cu. [doi:10.2320/matertrans.ME200823](Received December 15, 2008; Accepted March 18, 2009; Published May 13, 2009)Keywords: dealloying, bulk metallic glass, Cu
Hitoshi Matsuda - One of the best experts on this subject based on the ideXlab platform.
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Catalytic activity of noble metals for metal-assisted chemical etching of silicon
Nanoscale Research Letters, 2012Co-Authors: Shinji Yae, Yuma Morii, Naoki Fukumuro, Hitoshi MatsudaAbstract:Metal-assisted chemical etching of silicon is an electroless method that can produce porous silicon by immersing metal-modified silicon in a Hydrofluoric Acid Solution without electrical bias. We have been studying the metal-assisted Hydrofluoric Acid etching of silicon using dissolved oxygen as an oxidizing agent. Three major factors control the etching reaction and the porous silicon structure: photoillumination during etching, oxidizing agents, and metal particles. In this study, the influence of noble metal particles, silver, gold, platinum, and rhodium, on this etching is investigated under dark conditions: the absence of photogenerated charges in the silicon. The silicon disSolution is localized under the particles, and nanopores are formed whose diameters resemble the size of the metal nanoparticles. The etching rate of the silicon and the catalytic activity of the metals for the cathodic reduction of oxygen in the Hydrofluoric Acid Solution increase in the order of silver, gold, platinum, and rhodium.
Shinji Yae - One of the best experts on this subject based on the ideXlab platform.
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Catalytic activity of noble metals for metal-assisted chemical etching of silicon
Nanoscale Research Letters, 2012Co-Authors: Shinji Yae, Yuma Morii, Naoki Fukumuro, Hitoshi MatsudaAbstract:Metal-assisted chemical etching of silicon is an electroless method that can produce porous silicon by immersing metal-modified silicon in a Hydrofluoric Acid Solution without electrical bias. We have been studying the metal-assisted Hydrofluoric Acid etching of silicon using dissolved oxygen as an oxidizing agent. Three major factors control the etching reaction and the porous silicon structure: photoillumination during etching, oxidizing agents, and metal particles. In this study, the influence of noble metal particles, silver, gold, platinum, and rhodium, on this etching is investigated under dark conditions: the absence of photogenerated charges in the silicon. The silicon disSolution is localized under the particles, and nanopores are formed whose diameters resemble the size of the metal nanoparticles. The etching rate of the silicon and the catalytic activity of the metals for the cathodic reduction of oxygen in the Hydrofluoric Acid Solution increase in the order of silver, gold, platinum, and rhodium.
Wenjing Wang - One of the best experts on this subject based on the ideXlab platform.
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anatase tio2 single crystals with exposed 001 and 110 facets facile synthesis and enhanced photocatalysis
Chemical Communications, 2010Co-Authors: Min Liu, Lingyu Piao, Lei Zhao, Zijie Yan, Chunlan Zhou, Wenjing WangAbstract:Anatase TiO2 single crystals with exposed {001} and {110} facets have been successfully synthesized using a modified hydrothermal technique in the presence of hydrogen peroxide and Hydrofluoric Acid Solution; these single crystals exhibited enhanced photocatalytic activities for degradation of Methylene Blue dye under ultraviolet light irradiation.
Hiroshi Nishikawa - One of the best experts on this subject based on the ideXlab platform.
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Dealloying of Cu–Zr–Ti bulk metallic glass in Hydrofluoric Acid Solution
2020Co-Authors: Hiroya Abe, Kazuyoshi Sato, Hiroshi Nishikawa, Tadashi Takemoto, Mikio FukuharaAbstract:The dealloying behavior of Cu 60 Zr 30 Ti 10 metallic glass was investigated under free corrosion conditions using Hydrofluoric Acid (HF) Solutions at room temperature. After immersing in HF Solutions with various concentrations (0.05, 0.1, 0.5 and 1 M) for 300 s, color of all samples changed to be pinkish or peachy, which was ascribed to Cu based on the XRD patterns. According to the SEM-EDS study, HF immersion selectively leached the Zr and Ti elements, leaving Cu behind. Increasing the HF concentration increased the dealloying rate. Moreover, the HF concentration strongly influenced the surface morphology of the resulting Cu
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enhancement of solderability of cu60zr30ti10 bulk metallic glass by dealloying in Hydrofluoric Acid Solution
Quarterly Journal of The Japan Welding Society, 2011Co-Authors: Takehiro Naoi, Hiroshi Nishikawa, Tadashi Takemoto, Mikio Fukuhara, Akihisa InoueAbstract:To extend the engineering applications of bulk metallic glasses (BMGs), it is necessary to create process to form appropriate BMG/BMG and BMG/crystalline metal joint. In this study, Hydrofluoric Acid (HF) Solution treatment and a laser soldering process were employed to enhance the solderability of Cu60Zr30Ti10 BMG. The surface treatment in HF Solution successfully dissolved surface Zr and Ti, resulting in concentration of Cu at the surface. A reflow soldering process using Sn-3.0 mass% Ag-0.5 mass% Cu (SAC) solder on this surface showed obvious dewetting because the thin Cu-rich layer dissolved into the molten solder. Laser soldering with a 0.01 s irradiation time, which produces rapid heating and cooling rates, offered good wettability of SAC solder and Sn-57 mass% Bi (SB) solder. At the interface between the SB solder and the HF-treated BMG foil, an intermetallic compound (IMC) layer was observed by scanning electron microscopy (SEM).
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dealloying of cu zr ti bulk metallic glass in Hydrofluoric Acid Solution
Materials Transactions, 2009Co-Authors: Hiroya Abe, Kazuyoshi Sato, Hiroshi Nishikawa, Tadashi Takemoto, Mikio FukuharaAbstract:metallic glass was investigated under free corrosion conditions using hydrofluoric Acid (HF)Solutions at room temperature. After immersing in HF Solutions with various concentrations (0.05, 0.1, 0.5 and 1M) for 300s, color of allsamples changed to be pinkish or peachy, which was ascribed to Cu based on the XRD patterns. According to the SEM-EDS study, HFimmersion selectively leached the Zr and Ti elements, leaving Cu behind. Increasing the HF concentration increased the dealloying rate.Moreover, the HF concentration strongly influenced the surface morphology of the resulting Cu. [doi:10.2320/matertrans.ME200823](Received December 15, 2008; Accepted March 18, 2009; Published May 13, 2009)Keywords: dealloying, bulk metallic glass, Cu
