Wear Resistance of High Frequency Pulse Electroplating Ni-SiC Nano-Composite Coating
The Ni-SiC nano-composite coatings were prepared on the ring of stainless steel by using of high frequency pulse electroplating. Orthogonal experiment was used to study optimal dosage of the dispersant. The effect of some factors, such as current density, pH value, temperature , addition agent and so on, were studied. The characterization of Ni-SiC nano-composite coatings were studied by wear test. The effect of pulse frequency and the SiC concentration in the electrolyte on the wear resistance of Ni-SiC nano-composite coatings were studied. The morphology of the nano-composite coatings in wear test before and after were analyzed by SEM and the metaloscope photographs. The results show that Ni-SiC nano-composite coatings of high frequency pulse electroforming have better performance of wear resistance.
We determine from a two-band Hubbard Hamiltonian the spin susceptibility and the self-energy for the holes in the CuO 2 planes. From this, the quasiparticle lifetime τ, the spectral density, the electrical resistivity p resulting from spin scattering, and the NMR relaxation rate l/T 1 at Cu sites are calculated. Our results, which are expected to be valid for larger hole doping, are in reasonable agreement with experiment and indicate that an interplay of narrow-band phenomena and spin fluctuations leads to the observed anomalous normal-state properties