Journal of The Surface Finishing Society of Japan
Online ISSN : 1884-3409
Print ISSN : 0915-1869
ISSN-L : 0915-1869
Volume 65, Issue 6
Displaying 1-9 of 9 articles from this issue
Special Feature / Surface Technologies in Biomedical Devices
Reviews
Topics
Research Papers
  • Masashi SEKINE, Keiji SONOYA, Masanobu NAKAMURA
    2014 Volume 65 Issue 6 Pages 276-282
    Published: June 01, 2014
    Released on J-STAGE: June 01, 2015
    JOURNAL FREE ACCESS
    Properties of three thermal sprayed coatings were compared to select the effective sprayed coating for giving the thermal barrier to the Al alloy components of internal combustion engines. Results for coating 1 (top coat, Al2O3; bond coat, Ni-Cr), coating 2 (top coat, YSZ; bond coat, CoNiCrAlY), and coating 3 (SUS316) are presented below.
    (1) After thermal cycle testing, no crack or delamination was apparent in coating 3.Partial cracks and delamination were observed in the top coating in coatings 1 and 2.
    (2) All coatings have sufficient adhesion strength. The adhesion strength of coating 2 was especially high.
    (3) The thermal barrier property of coating 2 was better than that of coating 1 or coating 3.
    (4) Comprehensive evaluation results show that coating 2 had a good thermal barrier property and that coating 3 is a reasonable material because of its low cost as a thermal sprayed coating applied to Al alloy components of an internal combustion engine.
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Tecnological Paper
  • Ryu NAKAJIMA, Tomoyoshi KONISHI, Yoshihiro IKEDA
    2014 Volume 65 Issue 6 Pages 283-288
    Published: June 01, 2014
    Released on J-STAGE: June 01, 2015
    JOURNAL FREE ACCESS
    Plasma electrolytic oxidation (PEO) is a surface treatment technology using anodic oxidation. Recently, PEO coatings have been developed industrially, mainly for application to surface treatment of light metals. This study was conducted to elucidate the effects of metal oxyacid salts such as AlO2, SiO32− and [Zr(CO3)2(OH)2]2− on PEO coating formation. PEO coatings were formed from pyrophosphate electrolytes respectively containing metal oxyacid salts. PEO coatings showed high hardness as well as metal oxides sintered by molting and cooling. Each metal oxyacid salt was included in the coating, but surface morphology characteristics such as discharge channels and cracks mutually differed. Both the formation rate and contents of the metal oxyacid salts in the PEO coating increased in the following order: AlO2 <[Zr(CO3)2(OH)2]2−<SiO32−. Results show that addition of the metal oxyacid salts enhanced the PEO coating formation rate and uniformity. Presumably, this effect resulted from stability of the metal oxyacid salts in the electrolytes.
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