Author
Hidetoshi Fujii
Bio: Hidetoshi Fujii is an academic researcher from Osaka University. The author has contributed to research in topics: Welding & Friction stir welding. The author has an hindex of 48, co-authored 459 publications receiving 10057 citations.
Papers published on a yearly basis
Papers
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TL;DR: In this article, the relationship between welding parameters and tensile properties of the joints has been investigated and it was shown that the tensile property and fracture locations of the joint are significantly affected by the welding process parameters.
460 citations
15 Jan 2006-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: For different tool plunge downforces, the optimum FSW conditions of aluminum die casting alloy were examined in this paper, where three different types of defects were formed: large mass of flash due to excess heat input, cavity or groove-like defects caused by insufficient heat input; and cavity caused by abnormal stirring.
Abstract: For different tool plunge downforces, the optimum FSW conditions of aluminum die casting alloy were examined. The higher the tool plunge downforce is, the wider the range of the optimum FSW conditions is. The following three different types of defects are formed, depending on the FSW conditions. (1) A large mass of flash due to the excess heat input; (2) cavity or groove-like defects caused by insufficient heat input; and (3) cavity caused by the abnormal stirring. As for the abnormal stirring, it is clearly seen that the shape of the top part on the advancing side in the stir zone is completely different. For this type of defect, the effect of the tool plunge downforce is small, though the size of the defect due to insufficient heat input significantly decreases with the increasing downforce.
457 citations
15 Aug 2006-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, three types of carbon steels with different carbon contents (IF steel, S12C, S35C) were friction stir welded under various welding conditions.
Abstract: In order to determine the effect of the carbon content and the transformation on the mechanical properties and microstructures of the FSW carbon steel joints, three types of carbon steels with different carbon contents (IF steel, S12C, S35C) were friction stir welded under various welding conditions. Compared with IF steel, the microstructures and mechanical properties of the carbon steel joints are significantly affected by the welding conditions. The strength of the S12C steel joints increases with the increasing welding speed (decreasing the heat input), while the strength of the S35C steel joints shows a peak near 200 mm/min. This can be explained by the relationship between the peak temperature and the A 1 and A 3 points. When friction stir welding is performed in the ferrite–austenite two-phase region, the microstructure is refined and the highest strength is then achieved.
362 citations
15 Mar 2006-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, multi-walled carbon nanotubes (MWCNTs) were successfully dispersed into a magnesium alloy (AZ31) using friction stir processing (FSP). Distribution of the MWCNTs was changed on the basis of the travel speed of the FSP tool.
Abstract: Multi-walled carbon nanotubes (MWCNTs) were successfully dispersed into a magnesium alloy (AZ31) using friction stir processing (FSP). Distribution of the MWCNTs was changed on the basis of the travel speed of the FSP tool. The grain size of the MWCNTs/AZ31 surface composites was smaller than that of the FSPed AZ31 without the MWCNTs. The addition of the MWCNTs appears effective for fabricating the composites consisting of fine matrix grains. The maximum microhardness of these composites was ∼78 Hv, which is almost double that of the AZ31 substrate (41 Hv). It is considered that both the grain refinement of the AZ31 matrix and the reinforcement by the MWCNTs increased the microhardness of the surface composites.
342 citations
15 Oct 2006-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: SiC particles were uniformly dispersed into an AZ31 matrix by friction stir processing (FSP) and the SiC particles promoted the grain refinement of the AZ 31 matrix by FSP as discussed by the authors.
Abstract: SiC particles were uniformly dispersed into an AZ31 matrix by friction stir processing (FSP). The SiC particles promoted the grain refinement of the AZ31 matrix by FSP. The mean grain size of the stir zone with the SiC particles was obviously smaller than that of the stir zone without the SiC particles. The microhardness of the stir zone with the SiC particles was reached about 80 Hv due to the grain refinement and the distribution of the SiC particles. Additionally, the SiC particle/AZ31 region showed fine grains even at elevated temperatures (∼400 °C) resulting in the pinning effect by the SiC particles. In contrast, the microhardness was significantly decreased attributed to the abnormal grain growth of the FSPed AZ31 without the SiC particles.
277 citations
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TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.
Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …
33,785 citations
TL;DR: This paper presents a meta-analyses of the chiral stationary phase transition of Na6(CO3)(SO4)2, Na2SO4, and Na2CO3 of the Na2O/Na2O 2 mixture at the stationary phase and shows clear patterns in the response of these two materials to each other.
Abstract: Jenny Schneider,*,† Masaya Matsuoka,‡ Masato Takeuchi,‡ Jinlong Zhang, Yu Horiuchi,‡ Masakazu Anpo,‡ and Detlef W. Bahnemann*,† †Institut fur Technische Chemie, Leibniz Universitaẗ Hannover, Callinstrasse 3, D-30167 Hannover, Germany ‡Faculty of Engineering, Osaka Prefecture University, 1 Gakuen-cho, Sakai Osaka 599-8531, Japan Key Lab for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, China
4,353 citations
TL;DR: In this article, the authors deal with the fundamental understanding of the process and its metallurgical consequences, focusing on heat generation, heat transfer and plastic flow during welding, elements of tool design, understanding defect formation and the structure and properties of the welded materials.
1,811 citations
TL;DR: The field of surface science provides a unique approach to understand bulk, surface and interfacial phenomena occurring during TiO2 photocatalysis as mentioned in this paper, including photon absorption, charge transport and trapping, electron transfer dynamics, adsorbed state, mechanisms, poisons and promoters, and phase and form.
1,768 citations
TL;DR: Transparent conductors (TCs) have a multitude of applications for solar energy utilization and for energy savings, especially in buildings as discussed by the authors, which leads naturally to considerations of spectral selectivity, angular selectivity, and temporal variability of TCs, as covered in three subsequent sections.
1,471 citations