Journal of Advanced Mechanical Design, Systems, and Manufacturing
Online ISSN : 1881-3054
ISSN-L : 1881-3054
Volume 15, Issue 4
Displaying 1-15 of 15 articles from this issue
Special Issue on Advanced Manufacturing Technology
Papers(Special Issue)
  • Tatsuaki FURUMOTO, Kyota EGASHIRA, Kazushi OISHI, Satoshi ABE, Mitsugu ...
    2021 Volume 15 Issue 4 Pages JAMDSM0039
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    The quality of built parts by selective laser melting (SLM) relies on the comprehension of the phenomena that takes place during the melting and solidification of the metal powder. The scattering of spatter particle as liquid metal during SLM process affects the layer consolidation of powder bed in addition to the surface quality of built part. The present study is focused on the spatter particle behavior of maraging steel during SLM to achieve a thorough understanding of the phenomena that occur during the melting and fusing of the metal powder. The spatter particles are tracked using high speed imaging, and the effects of the process parameters on the spatter particle behavior are investigated. The spatter particles ejected from the melt pool are also physically and chemically evaluated. The results showed that the spatter particles were classified as being spherical or satellite types, according to their scattered volumes; some spatter particles were larger than the particles in the initial metal powder. Most spatter particles were ejected from the droplet formed around the melt pool and from the melted powder in front of the melt pool; the number of spatter particles ejected from the melt pool was relatively low. The surface roughness affected the generation locations and tracks of the spatter particles, and the substrate surface wettability was the principal factor affecting the spatter particle behavior.

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  • M. J. Mohammad FIKRY, Shinji OGIHARA, Vladimir VINOGRADOV
    2021 Volume 15 Issue 4 Pages JAMDSM0040
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    Matrix cracking in CFRP laminates results in degradation of mechanical properties of the material and appearance of residual strains. In this study, the residual strains are investigated experimentally and analytically for CFRP [0/756]s laminates. The typical stress-strain curves of cracked CFRP always show the presence of residual strain, a nonrecoverable strain in the laminates as the strain does not return to 0% even after being unloaded back to 0 MPa. This is a phenomenon where the matrix cracking in laminates increases the residual strain due to relaxation of curing stresses. Initially, the coefficients of thermal efficiency (CTE) of the laminates is measured to be used in the analysis to predict the residual strain due to the matrix cracks. The strain gauges were used in this study to measure the strains. Due to very small residual strains at the unloading condition, the residual strains were also measured at different stress levels for laminates with different crack densities and are compared with theoretical predictions. Time-dependent viscoelastic behavior of the material is also considered to accurately measure the residual strains due to the occurrence of matrix cracks. This was done by using the strain recovery test when the loads were stopped for 1-1.5 hours during unloading and the strain changes during these times were recorded. The experimental results of the residual strains are in reasonably good agreement with the theoretical predictions. The fiber non-linearity properties of the laminates may cause some experimental data to shift above the analytical line.

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  • Zhenglong FANG, Keisuke NAGATO, Naohiko SUGITA, Masayuki NAKAO
    2021 Volume 15 Issue 4 Pages JAMDSM0041
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    FeSiB metallic glass laminate is a state-of-the-art structure for magnetic core. Extremely high strength and hardness due to the amorphous matrix challenge its finishing process with severe tool wear and delamination. Meanwhile, grinding heat leads to crystallization of the material resulting in a magnetic deterioration. In this work, grinding data is presented for grind wheel wear, grinding force and surface quality when routing 7 mm thick FeSiB metallic glass laminate using electroplated CBN grinding points. Grinding experiments are carried out with grinding speeds of 0.5 and 1.5 m/s. Energy dispersive x-ray spectroscopy (EDS) and electron back scattered diffraction pattern (EBSD) analyses are conducted to inspect the delamination between the metallic foil layers and detailed microstructure of machined surface, respectively. The relation between the grinding force and delamination is discussed associated with the identification of crystallization condition near machined surface. As a result, severe plastic deformation between the layers and crystallization are identified which deteriorated the magnetic performance by inter-laminate circuit short and plastic strain. Load-displacement curve from nanoindentation confirmed the strain hardening level near machined surface.

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  • Toshiyuki OBIKAWA, Kenji YAGI, Mamoru HAYASHI
    2021 Volume 15 Issue 4 Pages JAMDSM0042
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    The evaluation of stress and temperature on the tool faces during machining is very important for understanding the fundamental mechanisms of cutting processes, developing cutting tools, optimizing cutting conditions. Although cutting temperature has been often measured using the tool-chip thermocouple method, a two-color pyrometer, thermography, etc., measurement of stress on the tool face has been hardly reported. For this reason, a cutting tool with a thin film stress sensor in a layer structure of coating on the rake face was developed for orthogonal cutting. The film sensor was made of manganin, a copper-manganese-nickel alloy having piezoresistive effect. The manganin was coated on the rake face of polished tool insert of silicon nitride by magnetron sputtering in a specific pattern having a line 30 micrometer wide and 0.2 micrometer thick along the cutting edge. Then, the rake face was further coated with silicon nitride for protecting the thin stress sensor. After the calibration of the sensor, the tool was applied to orthogonal cutting experiment, in which MC Nylon® and polyvinyl chloride were machined at a very low cutting speed. For four levels of uncut chip thickness from 0.05 to 0.20 mm the stress was measured for MC Nylon. A trapezoidal distribution of normal stress, which had been reported for soft materials by photoelasticity method, was also obtained from the measured stresses in this study.

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  • Koji SHIMANUKI, Akira HOSOKAWA, Tomohiro KOYANO, Tatsuaki FURUMOTO, Yo ...
    2021 Volume 15 Issue 4 Pages JAMDSM0043
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    Tool flank temperature at various intervals after cutting ISO C45 steel through dry turn-milling is measured using a two-color pyrometer with an optical fiber in order to investigate the cutting characteristics. The complicated undeformed chip geometry, which depends on various parameters such as cutting tool diameter, nose radius of cutting tool, number of tooth, workpiece diameter, tool-work revolution speed ratio, depth of cut, feed per tooth, tool axis offset, and cutting distance, is analyzed and visualized by the 3D-CAD system. The effect of cutting parameters associated with material removal rate (MRR) such as workpiece diameter, revolution speed, and feed rate on tool flank temperature is investigated in this study. The analysis by the 3D-CAD system indicated that workpiece diameter affects tool flank temperature, and an increase in 10 mm in diameter results in approximately 40 °C higher temperature at any workpiece revolution speed due to the variation in undeformed chip geometry. The tool flank temperature increases as the feed rate and workpiece revolution speed increase because the cross-sectional cutting area of undeformed chip increases with workpiece revolution speed, and the cutting time during the engagement of each flute also increases with feed rate. Further, almost similar values are obtained between the tool flank temperature and MRR when both the workpiece revolution speed and feed rate are changed.

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  • Masato OKADA, Shin TERADA, Yuki KATAOKA, Takeshi KIHARA, Takuya MIURA, ...
    2021 Volume 15 Issue 4 Pages JAMDSM0044
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    This paper investigates the burnishing characteristics of a developed sliding burnishing method with active rotary tool targeting a martensitic stainless steel. Two types of martensitic stainless steel, annealing (AN) stainless steel and quenching and tempering (QT) stainless steel, were targeted. The burnishing characteristics evaluated included surface roughness, profile, microstructure, subsurface hardness, bending property, and corrosion resistance. A sufficiently smooth surface, approximately Ra = 0.1 μm and Ra = 0.016 μm in both materials, respectively, was obtained using the developed burnishing method; irregular profile smoothing occurred due to the material flow of the subsurface. The subsurface hardness increased at a depth of 40 μm or more when using the developed burnishing method on the AN material, but no effect was observed for the QT material. Moreover, the bending yield point and strength of the sheet shape workpiece increased by applying the burnishing process to the AN material. The influence of the burnishing process on the bending properties was also observed for the QT material. Corrosion resistance, which evaluated by the salt-spray test, can be improved through the burnishing process in AN material.

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  • Masaaki KIMURA, Akira YONEDA, Masahiro KUSAKA, Koichi KAIZU, Kazuhiro ...
    2021 Volume 15 Issue 4 Pages JAMDSM0045
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    To obtain multimaterial structures composed by various materials as the right man in the right place for improvement of the additional value of some products or parts, the easy manufacturing method of the dissimilar metal joint is necessary. This paper described the weldability and its improvement of the friction welded joint between ductile cast iron (JIS FCD400) and typical Al-Mg alloy (JIS A5052). When both materials welded, only the A5052 side was unilaterally deformed and that was exhausted as flash during the friction process regardless of the friction welding condition. The relatively high tensile strength of the joint was obtained when that was made with a friction speed of 27.5 s−1, a friction pressure of 20 MPa, a friction time of 1.5 s, and a forge pressure of 270 MPa. However, the joint had approximately 77% in the tensile strength of the A5052 base metal and that was fractured at the weld interface. The tensile strength of joints, which were made with other friction welding conditions, was lower than that of this friction welding condition. Although the weld interface of the joint had no intermetallic compound interlayer, the fractured surface at the A5052 side had the C element as the graphite particles that were supplied from the FCD400 side. To improve the joint strength, the graphite particle was reduced from the weld faying surface at the FCD400 side by decarburization treatment before welding. The joints had approximately 97% in the tensile strength of the A5052 base metal, and one of joints was fractured at the A5052 base metal. Thus, the graphite particle at the FCD400 side influenced the weldability between FCD400 and A5052. In conclusion, the joint with high tensile strength as well as the possibility for the improvement of the fractured point of them could be obtained when they were made with an opportune friction welding condition and no graphite particles at the weld faying surface of the FCD400 side.

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  • Krishan Chanaka WICKRAMASINGHE, Hiroyuki SASAHARA, Masatoshi USUI
    2021 Volume 15 Issue 4 Pages JAMDSM0046
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    Machining is a prominent manufacturing method used in automobile, aerospace, and marine industries. Most of the materials that are frequently consumed in such industries are difficult to machine via conventional techniques. Difficult-to-cut materials require advanced processing approaches, and better cooling and lubrication conditions. Thus, manufacturing industries tend to use petroleum-oil-based metal working fluids (POMWF) because of their desirable characteristics of cooling and lubrication when applied to machine difficult-to-cut materials. However, POMWFs adversely affect human health and environment throughout their life cycle. Recently, several scientists have demonstrated that the vegetable oils have tribological properties which make better cooling and lubrication media for machining operations. Hence, the authors have formulated a white-coconut-oil-based water-soluble MWF (COMWF) for use as an alternative to toxic and hazardous POMWFs. The performance of novel MWF was evaluated by applying the minimum quantity lubrication approach to machine Inconel 718 and AISI 304. Machining experiments were conducted under controlled cutting conditions to investigate the work-tool interface (WTI) temperature, cutting forces and to benchmark the proposed MWF to a commercially available synthetic ester based MWF (SEMWF). The newly developed green MWF enabled WTI temperatures and cutting forces that were more desirable than those obtained using the SEMWF. A thermophysical model was also created using commercially available software to simulate the WTI temperature and to visualize the chip formation of difficult-to-cut materials. The novel COMWF was effectively used to machine the selected difficult to cut materials (i.e., Inconel 718 and AISI 304); furthermore, its potential as a replacement for the hazardous POMWFs to ensure industrial sustainability was demonstrated.

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  • Shoichi TAMURA, Kodai SEKIGAWA, Takashi MATSUMURA
    2021 Volume 15 Issue 4 Pages JAMDSM0047
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    In the automated machining processes, tool damage should be managed to assure product qualities, promote machine tool performance and reduce production time and cost. In drilling process, the cutting process changes along the cutting edge; and the tool wear is not uniform. This paper presents a monitoring of the tool wear distribution with measuring the cutting force in drilling with a twist drill. The cutting force increases with the cutting area in the edge penetration into workpiece in drilling. In the proposed approach, the cutting edges are divided into small discrete segments. The increasing rate of the cutting force at a segment is associated with the normal forces loaded at the cutting area. The normal force distributions, then, are estimated for the cutting edge damage. The widths of flank wear lands along the cutting edge are monitored based on the increase of the normal force distribution. The cutting tests were conducted to validate the presented approach with measuring the cutting force in drilling of carbon steel. The presented approach estimates the tool wear distribution on the edge with the cutting time. The average stress distribution loaded on the flank wear land is also estimated in the regression analysis.

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  • Hao DUAN, Shinya MORITA, Takuya HOSOBATA, Masahiro TAKEDA, Yutaka YAMA ...
    2021 Volume 15 Issue 4 Pages JAMDSM0048
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    Aspherical or free-form optical surface machining using an ultra-precision machine tool is a common and effective method used in the manufacturing of precision optics. However, this method sometimes causes waviness due to mid-spatial frequency (MSF) motion errors of the machine. This waviness lowers the quality of the optical surface. To compensate for the motion error, we use the waviness of the motion error of the axial displacement of an ultra-precision machine tool. This waviness is obtained by a non-contact on-machine metrology (OMM) system that measures an optical flat as a reference. The OMM system consists of a displacement probe and a machine tool axis position capture device. The probe system uses a chromatic confocal probe on an ultra-precision machine tool to evaluate the form deviation of the workpiece with 1-nm resolution. The axis position capture system uses a linear-scale signal branch circuit on each axis of the ultra-precision machine tool. The OMM system is tested in terms of accuracy and repeatability. Through shaper cutting experiments of an oxygen-free copper (OFC) workpiece with feed-forward motion error compensation, we reduce the peak-to-valley (p-v) profile error from 125.3 nm to 42.1 nm.

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  • Hidetaka FUJII, Takashi ONISHI, Chinhu LIN, Moriaki SAKAKURA, Kazuhito ...
    2021 Volume 15 Issue 4 Pages JAMDSM0049
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    In cylindrical traverse grinding, a slender workpiece is bent by the normal grinding force due to its low stiffness. Consequently, a form error is generated by the elastic deformation of the workpiece during the grinding process. To prevent such deformation of the workpiece, a steady rest is generally used. However, when the contact point between the workpiece and the steady rest is ground, the pushing force of the steady rest is lost, and the elastic deformation of the workpiece is increased immediately. As a result, a step shape error is generated at the contact point. To improve the use of the steady rest, the elastic deformation of the workpiece during the grinding process is simulated using the beam model considering the steady rest in this study. From the analysis results, it was determined that placing the steady rest outside the grinding part can reduce the elastic deformation of the workpiece. In addition, the traverse speed was controlled to maintain a constant elastic deformation. Through grinding experiments, it was confirmed that the form accuracy of the slender workpiece was improved by setting the steady rest outside the grinding part and adjusting the traverse speed.

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  • Xiaoqi SONG, Yukio TAKAHASHI, Weiming HE, Tohru IHARA
    2021 Volume 15 Issue 4 Pages JAMDSM0050
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    Built-up layer (BUL) formed on the tool rake face during cutting has the tool protective effect. As BUL can change the shape of tool resulting in variation of rake angle and edge radius, it may have significant influences on the cutting phenomena such as tool wear, cutting forces, and surface integrity. SUS304 stainless steel is very difficult to cut, leading to the rapid tool wear and poor surface quality. It also has a high tendency to form BUL during cutting due to its high work hardening rate and high chemical affinity. To actively and purposefully utilize BUL, the effects of the size of BUL on the wear of uncoated cemented carbide tools in dry cutting of SUS304 were investigated using the experimental and analytical methods in this study. The model for cutting processes included the effect of the size of BUL/BUE was presented. The cutting parameters were chosen to induce the stable BUL formation. After cutting, the worn cutting tools were analyzed using the laser confocal microscopy and scanning electron microscopy. It was confirmed that BUL can reduce the tool flank wear rate in the steady-state wear when its height is equal to or less than the uncut chip thickness. The results also showed that BUL formed at cutting speed 40 m/min not only can reduce the tool flank wear rate but also has few influences on the amplitude variation of cutting forces and surface roughness. Meanwhile, using the obtained experimental results and proposed model, simulation was conducted to evaluate the effects of the size of BUL on the tool flank wear formation. It was confirmed that BUL, especially when its height is close to the uncut chip thickness, which reduces the real rake angle to negative, can reduce the normal stress on the tool flank face and lead to a decrease in the tool flank wear rate.

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  • Hiroki OTA, Kristine Munk JESPERSEN, Kei SAITO, Keita WADA, Atsushi HO ...
    2021 Volume 15 Issue 4 Pages JAMDSM0051
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    In recent years, for the aim of weight reduction of transportation equipment, carbon fiber reinforced thermoplastics (CFRTPs), which have high recyclability and formability, are becoming suitable for mass production. Additionally, with the development of multi-material structures, excellent technologies are required for joining metals and CFRTPs. Presently, adhesive bonding and mechanical joining methods are employed for joining dissimilar materials, however, these methods still have some problems. Therefore, an alternative bonding method that does not use adhesives or employ mechanical joining is required for joining CFRTPs and metals. This study focuses on direct bonding between the CFRTP laminate and an aluminum alloy by fabricating a nanostructure on the aluminum alloy surface. The nanostructure penetrates the CFRTP matrix, causing an anchoring effect that improves the bonding strength significantly. The influence of the nanostructure on the energy release rate of the directly bonded CFRTP and aluminum was evaluated by static double cantilever beam testing. Because of the difference in thermal expansion coefficients of the CFRTP laminate and the aluminum alloy, significant residual stresses are generated. The effect of the thermal residual stresses on the energy release rate along with the resulting mode mixity (mode I and II) was determined. Results reveal that the critical energy release rate is improved by the nanostructure and mode I contribution of the energy release rate is increased for the nanostructure case.

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  • Yuya OMIYA, Kenji TOYOTA, Ryota NAKANISHI, Togo SHINONAGA, Tadashi SHI ...
    2021 Volume 15 Issue 4 Pages JAMDSM0052
    Published: 2021
    Released on J-STAGE: June 30, 2021
    JOURNAL FREE ACCESS

    With recent improvements in adhesive performance, adhesive joints are being increasingly used in various industrial fields. Despite their advantage of joining dissimilar adherends, adhesive joints are considered unsuitable for key components of mechanical structures due to their large variation in joint strengths. There are many factors that affect the strength of adhesive joints. However, the general bonding mechanisms are (1) mechanical, (2) physical, and (3) chemical bonding. The adhesion mechanism is complex because these phenomena occur simultaneously. Thus, it is necessary to consider these factors separately. Moreover, it is important to understand the bonding mechanism of interfaces in adhesive joints and to improve the reliability of the joint strength. In this study, the tensile strengths of single lap joints were measured to investigate the influence of large-area EB irradiation on strength characterization of adhesive joints. Aluminum alloy plates (A6061) were used as the adherend. Other surface treatments, which were sanding by emery paper, shot blast, and plasma irradiation, were also conducted for comparisons. Each treated surface of the adhered was examined with respect to the surface profile, wettability, and surface analysis by XPS. Results showed that the wettability of treated surfaces of adherend improved, and tensile strength of surface treated adhesive joints was also improved compared with that of the non-treated specimen. Specifically, the strength of the joint with EB irradiation was 1.9 times larger than that of the non-treated specimen. Finally, the effect of large-area EB irradiation on adhesive characterization was discussed.

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