Kagoshima Prefectural Institute of Industrial Technology

Kirishima city, Japan

Kagoshima Prefectural Institute of Industrial Technology

Kirishima city, Japan

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Kondo E.,Kagoshima University | Iwamoto R.,Kagoshima Prefectural Institute of Industrial Technology | Kobaru Y.,Kagoshima National College of Technology
Proceedings of the 15th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2015 | Year: 2015

Purpose of this study is to relate area of tool wear land of cutting edge with local width of wear which generates finished surface in ultra-precision cutting of aluminium alloy. To achieve this purpose, the relationship between the area of wear land and the local width of wear was experimentally investigated in ultra-precision face turning of aluminium alloy with a single crystal diamond tool having large nose radius. As a result of the cutting tests and measurements, it was found that local widths of wear land obtained under different cutting conditions were formulated by a function if local width of wear land was normalized by local uncut chip thickness, distance from top end of wear land was normalized by width of cutting cross section, and area of wear land was normalized by area of cutting cross section.


Nagatsuka K.,Osaka University | Sechi Y.,Kagoshima Prefectural Institute of Industrial Technology | Miyamoto Y.,Toyo Tanso | Nakata K.,Osaka University
Materials Science and Engineering B: Solid-State Materials for Advanced Technology | Year: 2012

The effect of Ti serving as an activator in a eutectic Ag-Cu alloy filler metal in dissimilar laser-brazed joints of isotropic graphite and a WC-Co alloy on the joint strength and the interface structure of the joint is investigated in this study. To evaluate the joint characteristics, the Ti content in the filler metal was increased from 0 to 2.8 mass%. The laser brazing was carried out by irradiating a laser beam selectively on the WC-Co alloy plate in Ar atmosphere. The threshold content of Ti required to join isotropic graphite to WC-Co alloy was 0.4 mass%. The shear strength at the brazed joint increased rapidly with increasing Ti content up to 1.7 mass%, and a higher Ti content was found to be likely to saturate the shear strength to a constant value of about 14 MPa. The isotropic graphite blocks also fractured at this content. The concentration of Ti observed at the interface between isotropic graphite and the filler metal indicates the formation of an intermetallic layer of TiC. © 2011 Elsevier B.V. All rights reserved.


Umeda M.,Kyushu Institute of Technology | Mure Y.,Kagoshima Prefectural Institute of Industrial Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

The design tasks of cold forged products are very important because they have a great influence on the quality of the final products and the life of the forging dies. However, the design expertise required for the design tends to get scattered and lost, and therefore there is a need for a framework that will enable the accumulation, utilization and evolution of this expertise. The authors have been developing a knowledge-based system to support process planning and the design of dies and die-sets for cold forged products. The knowledge base contains design knowledge on cold forging, which is systematized based on the formal definition of die design problems and on methods with high generality for resolving these problems. These features facilitate the improvement of product quality using an exhaustive search of process plans and die structures, and the improvement of design performance by automating the design work. They also make it easier to pass on and evolve expertise by allowing design experts to self audit and maintain their own knowledge base. The proposed system has been applied to several cold forged products. Experiments show that it can generate multiple forging process plans, dies, and die-sets based on the design knowledge, and that feasible solutions can be obtained within a practical time span. © 2011 Springer-Verlag Berlin Heidelberg.


Kondo E.,Kagoshima University | Iwamoto R.,Kagoshima Prefectural Institute of Industrial Technology | Kobaru Y.,Kagoshima University
Advanced Materials Research | Year: 2014

Large wear of diamond tools for ultra-precision cutting of soft metals deteriorates quality of machined surface, and the worn tools have to be replaced with new tools when the tool wear reaches limited wear land width of cutting edge generating finished surface. However, it is difficult to predict the tool life since all cutting tools have individual tool life. Therefore, the purpose of this study is to estimate wear land width of cutting edge of a single crystal diamond tool having large nose radius by using static cutting forces during machining. As a result of the cutting tests and measurements, it was found that the ratio of thrust force to principal force had good relation with the ratio of flank wear land area to cutting cross section area. Furthermore, according to some detailed observation of flank wear, width of flank wear land was greatly related to uncut chip thickness obtained under different cutting conditions and it was found that width of flank wear land could be estimated by measured static cutting forces and cutting conditions. © (2014) Trans Tech Publications, Switzerland.


Sechi Y.,Kagoshima Prefectural Institute of Industrial Technology | Nagatsuka K.,Osaka University | Nakata K.,Osaka University
IOP Conference Series: Materials Science and Engineering | Year: 2014

Laser brazing with Ti as an active element in silver-copper alloy braze metal has been carried out for binder-less cubic boron nitride and tungsten carbide, using silver-copper- titanium braze alloys with titanium content that varied between 0.28 mass% and 1.68 mass%. Observations of the interface using electron probe microanalysis and scanning acoustic microscopy show that efficient interface adhesion between binder-less cubic boron nitride and the silver-copper-titanium braze alloy was achieved for the braze with a titanium content of 0. 28 mass%. © Published under licence by IOP Publishing Ltd.


Nagatsuka K.,Osaka University | Sechi Y.,Kagoshima Prefectural Institute of Industrial Technology | Nakata K.,Osaka University
Journal of Physics: Conference Series | Year: 2012

SiC and WC-Co alloys were joined by laser brazing with an active braze metal. The braze metal based on eutectic Ag-Cu alloy with additional Ti as an active element ranging from 0 to 2.8 mass% was sandwiched by the SiC block and WC-Co alloy plate. The brazing was carried out by selective laser beam irradiation on the WC-Co alloy plate. The content of Ti in the braze metal was required to exceed 0.6 mass% in order to form a brazed joint with a measurable shear strength. The shear strength increased with increasing Ti content up to 2.3 mass%Ti and decreased with a higher content. © Published under licence by IOP Publishing Ltd.


Sechi Y.,Kagoshima Prefectural Institute of Industrial Technology | Nagatsuka K.,Osaka University | Nakata K.,Osaka University
Journal of Physics: Conference Series | Year: 2012

Laser brazing with Ti as an active element in Ag-Cu alloy braze metal has been successfully applied to dissimilar joining of h-BN and WC-Co alloy in Ar (99.999% purity) gas flow atmosphere without any evacuation process. Good wettability of the braze metal with h-BN and WC-Co alloy were confirmed by the observation and structural analysis of the interface by electron probe micro-analysis and scanning acoustic microscopy. The oxidation of titanium was not observed and this showed that the laser brazing with titanium as an active element in braze metal could be performed even in an Ar gas flow atmosphere without an evacuation process using a high-vacuum furnace. © Published under licence by IOP Publishing Ltd.


Mure Y.,Kagoshima Prefectural Institute of Industrial Technology
Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C | Year: 2011

In this research investigation, we have proposed a cold forging process planning reproduced the expert engineer's thinking process faithfully, and have also developed a practical knowledge-based system for axisymmetrical cold forged products. In this system, a forged product is represented as an aggregation of the forming patterns consisting of cylindrical pillar parts. The basic principle of the inference is the adjustment of the diameters of neighboring stepped cylinders so that they are all the same. Deformable process plans are generated by using expert knowledge regarding working limits and metal flow. The system can eliminate useless plans by using the knowledge of how to combine plural forming patterns in one process. Moreover, it can evaluate process plans by considering forming load, effective strain in the product and select an optimal one by using FEM simulation. We applied the system to actual forged products, and appropriate results were obtained including a practical process plan. The knowledge using the basic principle is widely applicable to various axisymmetrical forged product shapes. © 2011 The Japan Society of Mechanical Engineers.


Nagatsuka K.,Osaka University | Sechi Y.,Kagoshima Prefectural Institute of Industrial Technology | Ma N.,JSOL Corporation | Nakata K.,Osaka University
Science and Technology of Welding and Joining | Year: 2014

To investigate the mechanism of the occurrence of the microcracks produced in laser brazing of silicon carbide and cemented carbide using a silver–copper–titanium alloy as the filler metal, a numerical simulation for thermal cycle and thermal stress was performed using the finite element method. The laser-irradiated area of the cemented carbide was heated selectively, and almost uniform temperature distribution in the filler metal was obtained. The tensile thermal stress in the silicon carbide appeared near the interface between the silicon carbide and the filler metal, and the maximum principle stress at about 400 K during the cooling process reached the fracture strength of the silicon carbide. This resulted in the formation of microcracks in the silicon carbide which was observed in the experiment. © 2014 Institute of Materials, Minerals and Mining.


Sechi Y.,Kagoshima Prefectural Institute of Industrial Technology | Sechi Y.,Osaka University | Tsumura T.,Osaka University | Nakata K.,Osaka University
Materials and Design | Year: 2010

Using laser brazing process, we made the dissimilar joint of the boron nitride and tungsten carbide with an excellent functionality. In order to investigate the characteristic of joint, observation and structural analysis of its interface by the electron probe micro-analysis (EPMA) and the scanning acoustic microscopy were performed. The wetting property between h-BN and Ag-Cu-Ti braze was excellent, therefore no gaps were seen between them. Moreover, it was suggested that the Ti element, which is the active ingredient in Ag-Cu-Ti braze, reacted with N in h-BN to generate Ti-N composite phase as an interfacial precipitation and the generation of Ti-N composite phase was affected by the concentration of Ti in Ag-Cu-Ti braze. All fracture was formed in h-BN body near the interface and it seemed that the distribution of shear strength of 1.25%Ti to 1.68%Ti was within the margin of variation of bulk strength of h-BN. © 2009 Elsevier Ltd. All rights reserved.

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