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研究了通过模压铸造方法制造的氧化铝纤维与碳化硅颗粒混合增强铝基复合材料的干摩擦磨损性能。分别在室温、110℃,以及150℃条件下,进行了恒速0.36m/s(570r/min)的销盘式摩擦磨损实验。采用扫描电子显微镜观察干磨损表面特征,采用Arrhenius作图法研究相对磨损率,以便于进一步研究磨损机制。此外,讨论了纤维的方向性和纤维与颗粒的混合比作用。 相似文献
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Carbon fiber reinforced polymer composites are an extremely strong and light fiber-reinforced plastics that contains carbon fiber. In the present study, carbon fabrics were treated with various weight percentages of silane and were confirmed by spectral analysis (Fourier transform infrared). The treated carbon fibers were reinforced in hybrid resin (a combination of vinyl ester and epoxy at a ratio of 80:20) by using vacuum-assisted resin transfer mold technique. The composites were tested to know their tensile strength, modulus, flexural strength, modulus, and interlaminar shear strength. The hybrid matrix specimen was also prepared and tested for the mechanical properties and confirmed the miscibility by differential scanning calorimetry and X-ray diffraction. The mechanical properties of hybrid matrix composites (HMCs) were studied by fracture surface morphology with scanning electron microscope. The mechanical properties of the HMCs increased with silane treatment. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47695. 相似文献
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In this study, we aimed to synthesize restorative microcapsules using aminopropyl triethoxy silane through a combination of both microemulsions with a sol–gel technique and vinyl ester resin used as a healing component. The characteristic features of the microcapsules were analyzed by FTIR, XRD, and SEM and confirmed by the formation of core-shell microspheres with desired properties. The fabricated core-shell microspheres were reinforced into a hybrid resin (vinyl ester (80): epoxy (20)/silane modified carbon fiber composites) using the hand lay-up method. The effect of the microspheres on the mechanical and self-healing properties of composites was investigated. The mechanical test results showed a significant improvement in the flexural and impact strength by approximately 23% and 30%, respectively. The healing property was observed using the flexural test and the results indicated that the recovered strength almost 74% of the composites after initial damage was due to the healing medicine released from the broken portion of the core-shell microspheres that filled and cured the cracked area of the composites. 相似文献
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Fault detection of an induction motor was carried out using the information of the stator current. After synchronizing the
actual data, Fourier and wavelet transformations were adopted in order to obtain the sideband or detail value characteristics
under healthy and various faulty operating conditions. The most reliable phase current among the three phase currents was
selected using an approach that employs the fuzzy entropy measure. Data were trained with a neural network system, and the
fault detection algorithm was verified using the unknown data. Results of the proposed approach based on Fourier and wavelet
transformations indicate that the faults can be properly classified into six categories. The training error is 5.3×10−7, and the average test error is 0.103. 相似文献
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Numerical simulation and experimental study of the Vickers indentation testing of the Al2O3 ceramic coated by diamond-like carbon (DLC) layer were conducted. The numerical analysis was implemented by a two-dimensional
finite element (FE) axis symmetry model. FE analysis results gave insight into the fracture mechanism of DLC films coated
on brittle ceramic (Al2O3) substrates. The maximum principal stress field was used to locate the most expected area for crack formation and propagation
during the Vickers indentation testing. The results show that the median crack initiates in the interface under indenter,
before ring crack occurs as the indenter presses down. Finally, the plastic deformation appears when the indenter penetrates
into the substrate. The thicker DLC coating increases the Vickers hardness and fracture toughness. 相似文献
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Kejian Li Yinsheng He In Shik Cho Chang Soon Lee In Gyu Park Jung-il Song 《Materials and Manufacturing Processes》2015,30(2):194-198
Specimens of Inconel 690 were investigated after ultrasonic nanocrystalline surface modification (UNSM) using microhardness tests, electron backscattered diffraction, and transmission electron microscopy (TEM). After UNSM treatment, a 60% increase of hardness up to ~310 µm in depth was observed. Layer-by-layer TEM analysis showed well-refined grains and twins in addition to the high dislocations density. The mechanism of the microstructure refinement was attributed to the development of nano-grains, twin structures, and dislocations. 相似文献
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