Privious Issue

Volume 44 Number 4 (2013.12)

Special Feature

Nondestructive Testing and Evaluation Technology


Part I. Special Feature

Overview

Research Reports

  • 2. Defect Imaging Technique Using Ultrasonic Waves Produced by Laser IrradiationPDF(1,320kB)

    pages 1-8
    Morimasa Murase, Tsunaji Kitayama, Natsuki Ogura and Takahiro Hayashi


    This paper describes a novel non-immersion defect imaging technique using a pulsed laser and multiple receiving ultrasonic transducers. In this study, a clear image from which notch-like defects on the back surface of an aluminum plate can be identified was obtained. Moreover, it was shown that non-contact defect imaging can be performed by using high sensitivity air-coupled ultrasonic transducers as receiving sensors.


  • 3. Visualization of Surface Cracks and Monitoring of Back-wall Crack Growth via Potential Drop TechniquesPDF(1,135kB)

    pages 9-15
    Yasumoto Sato, Naomi Kawaguchi, Natsuki Ogura, Tsunaji Kitayama, Akira Ohashi and Yoshihiro Odagiri


    An intergranular stress corrosion crack (IGSCC) with complicated surface morphology was measured using the induced current potential drop (ICPD) technique. Lines indicating potential drops with sudden changes caused by the existence of cracks were observed in the plot of the potential drop distribution. The shapes of the lines agree well with those of the main and branched cracks, and therefore, the IGSCC was successfully visualized by using the ICPD technique.

  • 4. Moiré Deflectometry for Measuring Specular Surface ShapesPDF(4,801kB)

    pages 17-25
    Tomohiro Hirose



    Moiré deflectometry for measuring 3D specular surface profiles is presented. Moiré phenomena produced by two pairs of gratings are utilized to measure the normal vector distribution of a surface under examination. Surface profiles of curved mirrors with curvature from -20 to 20 m-1 and part of a miniature vehicle body were successfully measured using the proposed system.


  • 5. Three-dimensional Measuring Method for a Circular HolePDF(954kB)

    pages 27-33
    Toshihiko Tsukada, Keiichi Watanabe, Mitsuo Koide, Masahide Hirose, Yohei Horie and Yasunori Yamagishi



    In order to acquire the 3D positions of circular holes, which are widely used as reference points during the assembly of an automobile, we developed a method to measure the 3D coordinates of four feature points on the circumference of the circular hole while using the triangulation method. As a result, a measurement accuracy of ±0.05 mm or less (working distance: 200 mm) was obtained during an experiment.


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Part II. Highlighted Paper

Research Reports

  • 6. Synthesis of Cu Nanoparticles and Thermal Conductivities of Cu Nanoparticle JointsPDF(922kB)

    pages 35-42
    Toshitaka Ishizaki, Toshikazu Satoh, Ryota Watanabe, Yasushi Yamada, Fumiaki Osawa, Atsuki Kuno, Atsushi Tane and Masashi Yanase



    New synthesis method of Cu nanoparticles capped by fatty acid and amine was studied. The capping layers were thermally decomposed below 300℃ under an inert atmosphere. The Cu nanoparticle joint showed the highest thermal conductivity when compared with conventional joining materials.

  • 7. Thermodynamical Stability and Dehydriding Property of Calcium Borohydride
    Ca(BH4)2     PDF(1,539kB)

    pages 43-51
    Masakazu Aoki, Kazutoshi Miwa, Tatsuo Noritake, Hai-Wen Li and Shin-ichi Orimo



    We report our theoretical and experimental studies on the thermodynamical stability and dehydriding property of Ca(BH4)2. The polymorphic crystal structures of Ca(BH4)2 have been investigated by the synchrotron powder X-ray diffraction measurement. Using the structural information, the first-principles calculations have been performed to investigate the fundamental properties of Ca(BH4)2. The dehydriding reaction is predicted to be
    Ca(BH4)2→2/3CaH2+1/3CaB6+10/3H2
    , which is supported by the thermogravimetric analysis and the pressure-composition (p-c) isotherm measurement.


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