Yoshihara S.,Yamanashi University |
Takahashi A.,Yamanashi University |
Saito M.,Topy Industries. Ltd |
MacDonald B.J.,Dublin City University |
Manabe K.,Tokyo Metroplitan University
ASME 2010 International Manufacturing Science and Engineering Conference, MSEC 2010 | Year: 2010
A fuzzy inference system with an associated database was developed in order to determine the forming conditions required to obtain the objective height of a drawn cup using magnesium alloy sheet. The results from both experimental and finite element analyses (FEA) have been used for constructing the database which contains information on the forming conditions used and the resultant height of the drawn cup. A case study utilizing circular-cup deep-drawing was used to test the inference system, whereby experimental results for the height of the drawn cup using specific forming conditions (temperature, blank size and blank holding force) agreed with those predicted using the inference system. This confirms the validity of the inference system. Furthermore, a learning method was developed in order to improve the system using further experimental results, the FEA results and a fuzzy algorithm. The experimental analysis showed good agreement between the required objective height and the experimentally measured height of the drawn cup. Copyright © 2010 by ASME.
Terajima T.,Osaka University |
Takeuchi F.,Osaka University |
Nakata K.,Osaka University |
Adachi S.,Osaka Institute of Technology |
And 2 more authors.
Journal of Alloys and Compounds | Year: 2010
A composite coating containing WC/12Co cermet and Fe43Cr 16Mo16C15B10 metallic glass was successfully deposited onto type 304 stainless steel by high-velocity oxygen fuel (HVOF) spraying, and the microstructure and tribological properties were investigated. The microstructure of the coating was characterized by scanning electron microscopy/electron probe micro-analysis (SEM/EPMA) and X-ray diffractometry (XRD). The hardness, adhesion strength and tribological properties of the coating were tested with a Vickers hardness tester, tensile tester and reciprocating wear tester, respectively. The composite coating, in which flattened WC/12Co was embedded in amorphous Fe43Cr 16Mo16C15B10 layers, exhibited high hardness, good wear resistance and a low friction coefficient compared to the monolithic coating. The addition of 8% WC/12Co to the Fe43Cr 16Mo16C15B10 matrix increased the cross-sectional hardness from 660 to 870 HV and reduced the friction coefficient from 0.65 to 0.5. WC/12Co reinforcement plays an important role in improving the tribological properties of the Fe43Cr16Mo 16C15B10 coating. © 2010 Elsevier B.V.
Tamura K.,Japan National Institute of Materials Science |
Ohyama S.,Japan National Institute of Materials Science |
Ohyama S.,Toho University |
Umeyama K.,Topy Industries LTD. |
And 3 more authors.
Applied Clay Science | Year: 2016
The relationship between the morphology, flammability and mechanical properties of layered silicate-polyamide 66 (PA66) nanocomposites was investigated. The nanocomposites were composed of PA66, melamine-modified layered silicate (MLS) as a nanofiller, and/or melamine cyanurate (MC). Samples of MLS with different dispersion states were obtained by changing the melt-mixing procedures for PA66, MLS and MC. X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal analysis, strength tests, cone calorimetry tests and UL 94 vertical burning tests were used to examine the effects of MLS on the morphology, mechanical properties and flame resistance performance of the materials. The data revealed a correlation between the dispersion state of the MLS layers and flame retardancy. The nanocomposite manufactured by one-stage kneading of a mixture of PA66, MLS and MC earned a UL 94 rating of V0. The flame retardancy of dripping particles during combustion was found to be due to uneven dispersion of MLS in the PA66 matrix. © 2016.
Kim S.-C.,Tohoku University |
Yamaura S.-I.,Tohoku University |
Shimizu Y.,Topy Industries Ltd. |
Nakashima K.,Topy Industries Ltd. |
And 3 more authors.
Materials Transactions | Year: 2010
In this study, the newly designed bipolar plate for proton exchange membrane fuel cells (PEMFC) was produced by spray-coating the Ni 65Cr15P16B4 metallic glassy alloy on Al plate. The Ni65Cr15P16B4 metallic glass was adopted as a coating material because of its excellent corrosion resistance and the high velocity oxy-fuel (HVOF) spray coating was used for the metallic glass deposition on the Al plates having a bipolar plate flow field. The corrosion resistance of the Ni65Cr15P 16B4 glassy alloy film produced by the HVOF spray-coating was studied under simulated PEMFC environments. As a result, the Ni 65Cr15P16B4 glassy alloy film showed lower corrosion current density than the high-corrosion-resistant stainless steel SUS316L. Then, the electricity generation tests with the single cell having the Ni65Cr15P16B4 glassy alloy-coated bipolar plates produced in this study were conducted. As a result, the single cell with the metallic glass-coated bipolar plates showed very high I-V performance as well as the cell with the carbon bipolar plates. The long time durability tests for 24 h were also conducted at the constant current density of 200mA·cm-2. As a result, the single cell with the glass-coated bipolar plates showed no voltage drop during the test. So, it was found in this study that the Ni65Cr15P16B 4 glassy alloy-coated bipolar plate produced by the HVOF spray-coating have a potential for practical use for the fuel cells. © 2010 The Japan Institute of Metals.
Kim S.-C.,Tohoku University |
Kim S.-C.,Topy Industries Ltd. |
Yamaura S.-I.,Tohoku University |
Igarashi T.,Topy Industries Ltd. |
And 4 more authors.
Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals | Year: 2011
In this study, the newly designed bipolar plates for proton exchange membrane fuel cells (PEMFC) were produced by the HVOF spray-coating the Ni 65Cr15P16B4, Ni60Cr 20P16B4 and Ni55Cr 25P16B4 alloys on Al plates having a flow field. As a result of XRD observations, it was found that the HVOF spray-coated Ni65Cr15P16B4 and Ni 60Cr20P16B4 alloy films deposited on Al plates showed mainly a broad hallo peak coming from the glassy matrix and a small peaks from the crystalline phases. The spray-coated Ni55Cr 25 P16B4 alloy showed sharp distinct peaks coming from crystalline phases. So, it was difficult to prepare the coating layer with single glassy phase by the HVOF spray-coating in this study. The corrosion resistance of these Ni-Cr-P-B alloy films deposited by the HVOF-spray-coating was studied under simulated PEMFC environments. As a result, it was found that the corrosion current density of these films was smaller than that of the high-corrosion-resistant stainless steel SUS316L. Then the I-V performance of a single fuel cell with these bipolar plates produced in this work was studied and we found that the single fuel cells with the alloy-coated bipolar plates showed high I-V performance as well as the cell with the carbon bipolar plates. Among them, the Ni60Cr20P 16B4 alloy showed the highest I-V performance, showing the largest current density at 0.3 V. After that, the 24 h durability tests were conducted at the constant current density of 200 mA · cm-2. As a result, the cell voltage of a single fuel cell with the alloy-coated bipolar plates did not show significant voltage drop during the tests. It can be concluded that the most suitable alloy for bipolar plate prepared in this study is Ni60Cr20P16B4 alloy. XPS analysis of the surface layer of the Ni-Cr-P-B alloy-coated bipolar plates was conducted after the 24 h durability tests. As a result, the Cr2O3 passive film was found in all the Ni-Cr-P-B alloy surface films and also the P2O5 in the Ni65Cr15P 16B4 and Ni55Cr25P 16B4 alloy surface films and Ni(OH)2 in the Ni65Cr15P16B4 alloy surface film. This observation indicates that the surface passive film of Ni 60Cr20P16B4 alloy contains the Cr2O3 of the highest concentration among the three alloy surface films, resulting in the highest I-V performance and good durability. © 2011 The Japan Institute of Metals.
Kobayashi M.,Toyohashi University of Technology |
Hara H.,Toyohashi University of Technology |
Toda H.,Toyohashi University of Technology |
Sugiyama D.,Topy Industries Ltd |
Kuroda N.,Topy Industries Ltd
International Journal of Cast Metals Research | Year: 2012
Cast aluminium alloy has sometimes been utilised for various products after applying plasticworking combining with heat treatment. The thermomechanical treatment will bring not onlypositive effects (workhardening and grain refinement) but also negative effects (damage onparticles and increase of porosity) on the mechanical properties in the cast aluminium alloy. In thisstudy, the relation between microstructures and fatigue properties has been investigated in hotforged and heat treated Al-Si-Mg casting alloys with different Si contents. An ex situ observationof fatigue crack propagation showed different crack behaviours depending on the microstructuresarising from the different Si contents. The crack in the α phase propagated quickly incomparison with the crack located in the eutectic and grain boundaries in the Al-3·1Si-0·4Mgalloy. The crack propagation rate was not constant in the Al-7·7Si-0·4Mg alloy due to theagglomerated Si particles in the eutectic region. © 2012 W. S. Maney & Son Ltd.
Yanagimoto J.,University of Tokyo |
Dupin E.,University of Tokyo |
Liu J.-S.,Topy Industries Ltd. |
Yanagida A.,Tokyo Denki University
Procedia Engineering | Year: 2014
The importance of structural metals for industrial applications is based on their superior combination of mechanical properties - strength, elongation, toughness and corrosion resistance - Achieved at the end of forming processes. A numerical analysis for the prediction of microstructure is strongly required for the optimization of hot forming process parameters, because the microstructure of structural metals, which has the significant effects on mechanical properties, is strongly dependent to forming process conditions as well as the chemical composition. The off-line and on-line analyses of microstructure evolution are explained briefly, and the results of its application to hot strip rolling are presented. The linkage of microstructure analysis to kinetic property prediction of product is discussed, and finally, the remaining research topic, such as enlarging the analytical scheme to various alloys, is presented. © 2014 The Authors. Published by Elsevier Ltd.
Tsuchida N.,University of Hyogo |
Inoue T.,Japan National Institute of Materials Science |
Enami K.,TOPY Industries Ltd
Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals | Year: 2012
True stress (σ)-true strain (e) relationships until just before fracture, i.e., the plastic deformation limit, were estimated by the stepwise tensile test and the Bridgman equation for various metals and alloys with different crystal structures. The estimated σ-ε relationships were different from the nominal stress-strain curves including the conventional tensile properties. In the relationships between the true stress (σpdl) and true strain (εpdl) at the plastic deformation limit, SUS304 and SUS329J4L indicated a better σ pdl-εpdl balance. On the other hand, SUS329J4L, tempered martensite, and an ultrafine-grained steel showed superior results in the yield strength-εpdl balance. The estimated σ-ε relationship for the ultrafine-grained steel suggests that grain refinement strengthening can improve σ and ε up until the plastic deformation limit. The value of εpal became larger with increasing the reduction in area and a decrease in the fracture stress. The products of σpdland εpdl became larger with increasing work-hardening rate at the plastic deformation limit. © 2012 The Japan Institute of Metals.
Kondoh K.,Osaka University |
Fujita J.,Osaka University |
Umeda J.,Osaka University |
Imai H.,Osaka University |
And 3 more authors.
Materials Chemistry and Physics | Year: 2011
AZ61B alloy powder composite with Al2Ca fine dispersoids was developed by using CaO additive particles as raw materials. For synthesis of Al2Ca in the matrix, CaO particles were elementally and uniformly mixed with AZ61B alloy chips via ECABMA process. The mechanism in formation of Al2Ca intermetallics was investigated by XRD and SEM-EDS analysis when AZ61B alloy green compacts containing CaO additives were heat treated at 380-625 °C in argon gas atmosphere. A change in a standard free energy in formation of Al2Ca via reaction between CaO and Mg-Al alloy was calculated by using a standard Gibbs free energy of each element contained in the green compact. Both of the theoretical analysis by thermo-dynamic and experimental investigation clarified that Al2Ca and MgO were synthesized by employing Mg-Al alloy, not pure Mg as the matrix material. Microstructural analysis indicated that needle-like intermetallic of (Mg,Al)2Ca or Al3Ca4Mg were formed as intermediately created compounds in the solid-state reaction between CaO particles and Mg-Al alloy to synthesize Al2Ca and MgO dispersoids. © 2011 Elsevier B.V.
Topy Industries Ltd. and Nippon Paint Co. | Date: 2012-01-01
The present invention provides a method for coating an aluminum wheel using a coating composition capable of forming a coating film having a superior cosmetic property as well as an anticorrosive property much enough for preventing corrosion even in the use in an area where the coating film is susceptible to salt damage, and an aluminum wheel obtained by the method. A method for coating an aluminum wheel including applying an anticorrosive coating composition onto the aluminum wheel, and thereafter applying a clear coating composition to form a transparent multilayer coating film, wherein the anticorrosive coating composition contains an acrylic resin (1) having a weight average molecular weight of 50,000 to 140,000, a glass transition point of 20 to 50 C., a hydroxyl value of 10 to 50 mgKOH/g, and an acid value of 10 to 40 mgKOH/g, and an epoxy resin (2) having an epoxy equivalent of 210 to 1,000 g/eq and contains the epoxy resin (2) in an amount of 5 to 20 parts by weight on the solid matter basis to 100 parts by weight of the solid matter of the acrylic resin (1).