Breakdown Performance and Partial Discharge Development in Transformer Oil-Based Metal Carbide Nanofluids

In this work, the influence of semi-conductive SiC nanoparticles on the AC breakdown voltage and partial discharge development in natural ester oil FR3 is examined. Primarily, the dielectric constant and the electrical conductivity of the nanoparticles are measured following the broadband dielectric spectroscopy technique. The nanoparticles are added into the matrix following the ultrasonication process in three weight percentage ratios in order for their effect to be evaluated as a function of their concentration inside the base oil. The processing of the results reveals that the nanofluid containing SiC nanoparticles at 0.004% w/w demonstrates the highest AC dielectric strength improvement and shows the greatest resistance to the appearance of partial discharge activity. The mechanisms behind the aforementioned results are discussed in detail and confirmed by the broadband dielectric spectroscopy technique, which reveals that this particular nanofluid sample is characterized by lower dielectric constant and electrical conductivity than the one with double the weight percentage ratio.

Fabrication of Wear Resistance Ni/SiC nano composite Coating by Electro co-deposition

In this paper, we succeeded in obtaining a Ni/SiC nano composite coating using conventional electro deposition by adding different amount of SiC nanoparticles to a nickel-watt bath to be co-deposited. The effect of electro deposition conditions was studied by changing the amount of SiC nanoparticles in the nano composite, and the deposition current density which affects on the participation of SiC nanoparticles in the coating. The morphology and mechanical properties of the electrodeposited nano-composite were studied. The wear behavior of the nano-composite coatings was evaluated on a ball-on-disk test. It was found that the increased micro hardness and wear resistance of the nano-composite coatings increased with increasing content of the SiC nano-particulate in bath.

Mode-I and mode-II interlaminar fracture properties of high modulus pitch-based carbon fiber reinforced polymers containing different nanostructures

The mode-I and mode-II interlaminar fracture properties of high modulus pitch-based carbon fiber reinforced polymers (CFRPs) (fiber: K13C; resin: EX-1515 cyanate ester) modified with 20–30 nm β-SiC nanoparticles or multiwalled-carbon nanotubes (MWCNTs) were investigated. Different volume fractions of both the β-SiC nanoparticles (1, 2, 5, and 10 vol%) and MWCNTs (1, 3, 5, and 7 vol%) were tested. The values of the mode-I and mode-II interlaminar fracture toughness of the CFRPs containing the lowest volume fractions of these nanostructures were larger compared with the unfilled composite but decreased with increasing the volume fraction of the inclusions. No differences in mechanical properties were observed among the different nanostructure types.