• Title/Summary/Keyword: Functionally graded

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Improvement of Impact Resistance of B4C Tile Inserted B4Cp/Al7075 Hybrid Composites Through Interface Control (B4C tile 삽입 B4Cp/Al7075 하이브리드 복합재의 계면 제어를 통한 내충격 특성의 향상)

  • Park, Jongbok;Lee, Taegyu;Lee, Donghyun;Cho, Seungchan;Lee, Sang-Kwan;Hong, Soon Hyung;Ryu, Ho Jin
    • Composites Research
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    • v.33 no.5
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    • pp.235-240
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    • 2020
  • In this study, in order to improve the impact resistance of the B4C tile-inserted B4Cp/Al7075 hybrid composite, a control method of the B4C/Al7075 interface was developed and the characteristics of the controlled interface were analyzed. B2O3, Ni, and Si were coated on the B4C tile surface using additional thermal oxidation, electroless plating, and plasma spraying. The coated B4C tile is inserted into the B4Cp/Al7075 composite material using the liquid pressurization method. Interfacial energy, bonding strength, and impact resistance were measured to analyze the effect of the coating. All coatings enhanced interfacial energy, bonding strength, and impact resistance, and in particular, it was confirmed that the impact resistance increased by 86.8% when B2O3 coating was used. This study is significant in developing and analyzing a core surface treatment method that improves the performance of B4C/Al series composites, which are attracting attention as next-generation lightweight amour and bulletproof materials.

Effect of Sintering Time on Microwave Dielectric Properties of Layered Mg0.93Ca0.07TiO3-(Ca0.3Li0.14Sm0.42)TiO3 Ceramics (소결시간에 따른 적층형 Mg0.93Ca0.07TiO3-(Ca0.3Li0.14Sm0.42)TiO3 세라믹스의 마이크로파 유전특성)

  • Cho, Joon-Yeob;Yoon, Ki-Hyun;Kim, Eung-Soo;Kim, Tae-Hong
    • Journal of the Korean Ceramic Society
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    • v.39 no.9
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    • pp.890-895
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    • 2002
  • Effect of the sintering time on the microwave dielectric properties of the layered Functionally Graded Materials(FGMs) of the Mg0.93Ca0.07TiO3(MCT) with (Ca0.3Li0.14Sm0.42)TiO3(CLST) ceramics was investigated. The dielectric constant of layered FGMs specimens showed a nearly constant value and did not change significantly with sintering time. The quality factor, however, was affected by the relative density and thermal stress developed in each dielectric layer. With an increase of the relative density and the decrease of the induced thermal stresses, quality factor of the layered FGMs specimens increased and the quality factor was incluenced sensitively by the change of compressive stress developed in MCT layers which had a lower thermal expansion coefficient than that of CLST. For the layered FGMs specimen sintered at 1300$^{\circ}C$ for 9h, the compressive stress developed in MCT layer showed the maximum value, which, in turn, the quality factor of the specimen was the minimum value.