Study of the Corrosion Behavior of Nanocrystalline Ni-P Electrodeposited Coating

Abstract

The corrosion behavior of electrodeposited Ni-P coating in 5 pct (in weight) NaCl solution has been studied. The microstructure of the Ni-P electrodeposit displayed a layered structure composed of nanocrystalline grains revealed by transmission electron microscopy (TEM). With the increase in polarization potential and bath temperature, the corrosion rate as well as the weight loss was significantly increased. Under observation by a field-emission scanning electron microscope (FESEM), the pitting evolved into larger sizes with a diameter of approximately 30 mu m as the temperature and potential were increased to 50 A degrees C and 600 mV(SCE), respectively. Cracks and delamination among the layered structure were found inside the deepened corrosion pit. The increase in surface P content and the trace of the formation of phosphate were also observed by using X-ray photoelectron spectroscopy (XPS) analysis

The Effects of Microstructure on Cold Crack in High-Strength Weld Metals

“…Schematic illustration of crack propagation in various lath microstructure28) Micrograph illustrating the branching and blunted crack (a) optical micrograph and (b) SEM micrograph32) …”

Half-metallic surface states and topological superconductivity in NaCoO2from first principles

“…They constitute only half of a usual fermion, and obey the nonAbelian statistics [2], which is the key ingredient for the fault-tolerant topological quantum computation [3]. The Majorana states associated with zero energy mode have been predicted to exist in various systems [2,[4][5][6][7][8][9][10][11][12], nevertheless, their experimental realizations remain challenging due to the requirements of extreme conditions such as strong magnetic field, low temperature, or ultra-clean samples. In this letter, we will show that NaCoO 2 /superconductor hetorestructure is a new and simple platform for realizing such exotic states.…”

“…Unfortunately, such topological superconductors are very rare in nature, this leads to the proposals of possible "induced" p x + ip y order parameter through the proximity effect, particularly for materials in contact with the simplest s-wave superconductors [7][8][9][10][11][12]. The proposal by Fu and Kane [7] is to use the surface state of topological insulators [13][14][15], where the spin degeneracy is removed and yet strong proximity effect can be expected due to the characteristic helical spin texture of Dirac-type surface state.…”

“…The experimental setting can be in principles obtained from laboratory, however, since most known three-dimentional topological insulators [15][16][17][18] up to now are not good bulk insulators and important surface states may overlap with bulk states, experiments have to wait for development of well-controlled clean samples. It was proposed recently that semiconductor quantum wells with Rashba type SOC in proximity to s-wave superconductor will produce similar effect [8][9][10][11]. This may lower the experimental threshold, since well-controlled samples are available nowadays.…”

“…will be generated by the proximity effect, and the full Hamiltonian reads H = H 0 + H ∆ , which has been carefully studied previously [8][9][10][11]19]. The dominant pairing channel should have the spin po- larized p x +ip y symmetry, whose order parameter is given as ∆…”