نوع مقاله : مقاله پژوهشی
نویسندگان
گروه مهندسی مواد، واحد اهواز، دانشگاه آزاد اسلامی، اهواز، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction and Objectives: ZrB2-SiC composites are widely used in industeries such as aerospace due to their high melting points. This study investigates the effect of adding nano carbon black and silicon carbide (SiC) on the oxidation resistance of these composite at 1450 °C.
Materials and Methods: Five samples were prepared with the following compositions: pure ZrB₂, ZrB₂ containing 10 and 15 vol% nano carbon black, and ZrB₂-30 vol% SiC containing 10 and 15 vol% nano carbon black. The samples were sintered via spark plasma sintering at 1850 °C for 8 minutes under 35 MPa pressure in vacuum. Oxidation resistance was evaluated at 1450 °C in air for 0.5, 1, 1.5, 2, 3, and 5 hours. The weight of each sample was measured before and after oxidation .Scanning electron microscopy was used to examine the cross-sectional morphology of the oxidized layers, and phase identification was performed using X-ray diffraction.
Results: During oxidation at 1450 °C, the predominant oxidation phase in pure ZrB₂ and ZrB₂ containing 10 and 15 vol% nano carbon black was monoclinic ZrO₂. In the ZrB₂-30 vol% SiC composite containing 10 vol% nano carbon black, in addition to the primary phases, monoclinic ZrO₂, SiO₂, and B₂O₃ phases were also detected. The addition of 10 vol% nano carbon black reduced the oxidation layer thicknessfrom 129 ± 5 µm in pure ZrB₂ to 110 ± 6 µm in the ZrB₂ sample containing 10 vol% nano carbon black.
Conclusion: The ZrB₂–30 vol% SiC composite containing 10 vol% nano carbon black exhibited the lowest oxidation layer thickness (55 ± 3 µm) and the highest oxidation resistance.
کلیدواژهها [English]
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