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1.
Thermal barrier coatings (TBCs) are used to protect the hot sections of gas turbine engines and airplane engines. A TBC system comprises a substrate, bond coat, and TBC topcoat. The development of an accurate method for determining the Young’s modulus and Poisson’s ratio of TBC using a multilayered specimen is of importance. In this study, we applied the bending theory of a laminated plate to a three-layered material and proposed models to determine the Young’s modulus and Poisson’s ratio of the TBC layer using the bending strain of the TBC system specimen. Three methods were developed by utilizing (i) the coating biaxial strain, (ii) substrate biaxial strain, or (iii) coating and substrate biaxial strains. Subsequently, we determined appropriate dimensions of the specimen and span by using three-dimensional finite element analysis, and numerically verified the usefulness of the three proposed methods. However, the Young’s modulus and Poisson’s ratio determined using the multilayered specimen with a substrate are sensitive to experimental errors. Therefore, we evaluated the sensitivity of the three proposed methods to experimental error, and we determined the most insensitive method among them. Finally, we experimentally demonstrated the usefulness of this method. 相似文献
2.
Hideo Yamauchi Junichi Ikejiri Fumio Sato Hiroyuki Oshita Tsuyoshi Honma Takayuki Komatsu 《Journal of the American Ceramic Society》2019,102(11):6658-6667
In recent years, the expansion of demand for lithium ion batteries has resulted in soaring prices of the constituent resources. From the viewpoint of safety, studies on all-solid-state batteries are actively being carried out. In this study, we succeeded in driving all-solid-state batteries derived from nontoxic oxide glasses at room temperature without requiring scarce resources such as lithium and cobalt. The main structure of the ceramic batteries with a simple structure in which Na2FeP2O7 crystallized glass and β″-alumina solid solution are joined by pressureless cofiring at 550°C. During the crystallization of Na2O-Fe2O3-P2O5 glass, fusion with the β″-alumina solid solution is achieved. Reversible charge and discharge of 80 mAh/g were achieved at room temperature. It is not necessary to apply pressure during cell preparation or the use of the batteries. Furthermore, the strong junction at the cathode and electrolyte interface does not peel off during charge and discharge over a long period of 623 cycles. Ex situ X-ray photoelectron spectroscopy revealed partial Fe4+ induction and a reversible charge and discharge reaction even after overcharging to 9 V. It was demonstrated that Na2FeP2O7 is very stable against overcharging to 9 V. 相似文献
3.
Li Minggang Matsuura Hiroyuki Tsukihashi Fumitaka 《Metallurgical and Materials Transactions B》2019,50(6):2993-3001
Metallurgical and Materials Transactions B - Evolution of TiS in composition and morphology as well as the change in size distribution of TiS and TiN in Fe-40 masspctNi austenitic alloy during... 相似文献
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Tomoya Suzuki Kento Shiota Yu-ichiro Izato Masahiro Komori Koichi Sato Yasuyuki Takai Takayuki Ninomiya Atsumi Miyake 《International Journal of Hydrogen Energy》2021,46(11):8329-8343
Although hydrogen refueling stations (HRSs) are becoming widespread across Japan and are essential for the operation of fuel cell vehicles, they present potential hazards. A large number of accidents such as explosions or fires have been reported, rendering it necessary to conduct a number of qualitative and quantitative risk assessments for HRSs. Current safety codes and technical standards related to Japanese HRSs have been established based on the results of a qualitative risk assessment and quantitative effectiveness validation of safety measures over ten years ago. In the last decade, there has been much development in the technologies of the components or facilities used in domestic HRSs and much operational experience as well as knowledge to use hydrogen in HRSs safely have been gained through years of commercial operation. The purpose of the present study is to conduct a quantitative risk assessment (QRA) of the latest HRS model representing Japanese HRSs with the most current information and to identify the most significant scenarios that pose the greatest risks to the physical surroundings in the HRS model. The results of the QRA show that the risk contours of 10?3 and 10?4 per year were confined within the HRS boundaries, whereas the risk contours of 10?5 and 10?6 per year are still present outside the HRS. Comparing the breakdown of the individual risks (IRs) at the risk ranking points, we conclude that the risk of jet fire demonstrates the highest contribution to the risks at all of the risk ranking points and outside the station. To reduce these risks and confine the risk contour of 10?6 per year within the HRS boundaries, it is necessary to consider risk mitigation measures for jet fires. 相似文献
6.
Zou Xiaodong Matsuura Hiroyuki Wang Cong 《Metallurgical and Materials Transactions B》2019,50(3):1134-1138
Metallurgical and Materials Transactions B - The evolution behaviors of MnS inclusions during 1473 K heating have been systematically investigated for EH36 shipbuilding steel with Zr addition. It... 相似文献
7.
Shoji Eita Takahashi Ryuji Isogai Shosei Ito Naoto Kubo Masaki Tsukada Takao Fukuyama Hiroyuki 《Metallurgical and Materials Transactions B》2019,50(5):2454-2458
Metallurgical and Materials Transactions B - Normal spectral emissivity of molten Cu-Fe alloy with different compositions was measured at the wavelength of 807 nm using an electromagnetic... 相似文献
8.
Ireneusz Buganski Kotoba Toyonaga Hiroyuki Takakura Tsunetomo Yamada Marc de Boissieu Olivier Perez 《Materials Science & Technology》2020,36(9):989-995
ABSTRACTWe report a successful growth of the ZnMgHf F-type icosahedral quasicrystal in the form of faceted single grains. By varying the heat treatment parameters we were able to obtain single crystals with a quality suitable for a single crystal X-ray diffraction which was conducted in a synchrotron facility. Ab initio structure solution by a charge flipping algorithm manifests the existence of two types of Bergman clusters. Clusters are differentiated by the preferential occupation of the high-symmetry positions by hafnium in a rhombic triacontahedron, being the outer shell of the atomic cluster.This paper is part of a Thematic Issue on The Crystallographic Aspects of Metallic Alloys. 相似文献
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10.
Shinji Fukuda Kazuhiko Shimada Noriya Izu Hiroyuki Miyazaki Shoji Iwakiri Kiyoshi Hirao 《Journal of Materials Science: Materials in Electronics》2018,29(14):11688-11698
We observed crack generation and structural changes in electroless nickel–phosphorus (Ni–P) plating layers formed on copper-metalized silicon nitride substrates both during thermal cycling from ? 40 to 250 °C and during storage (not cycling) at 250 °C in order to investigate the effect of the phosphorus contents on crack generation and growth in the Ni–P platings. The used platings contained phosphorus at three different contents: 2.1 wt% [Ni–P(low)], 6.5 wt% [Ni–P(med)], and 10.9 wt% [Ni–P(high)]. The generation time and the amount of cracks were strongly dependent on their phosphorus contents. More cracks appeared after thermal cycling than after storage at 250 °C. In Ni–P(low), cracks were generated after 200 thermal cycles, whereas no cracks were observed even after 250 h of storage at 250 °C. In Ni–P(med) and Ni–P(high), both during thermal cycling and storage at 250 °C, cracks formed during or after crystallization of the amorphous layers. These results suggest that the primary factors affecting the generation of cracks in electroless Ni–P platings are crystallization of the Ni–P platings and repeated changes in thermal stress. 相似文献