Metal electrodeposition is the process of reduction reaction and crystallization of metal ions in an electrolytic cell according to the mechanism of electrolysis. Electrodeposition is one of the main methods for improving and enhancing the metal substrate property. Now, in order to overcome the defect of single electrodeposition with shortcomings of cracks, pores, pits, pocking and so on, the modern new techniques sprang up such as jet electrodeposition [1], ultrasonic vibration assisted electrodeposition [2] and composite deposition technology [3], greatly promoting the development of electrodeposition technology. Even the function materials were obtained that couldn’t be prepared by the ordinary smelting technology. The laser, with the unique
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The interaction between laser and liquid substance generates a series of mechanics-electric effect, thermoelectric effect and photoelectric effect, which will affect the grain nucleation, surface topography and the reduction reaction rate of the deposition. According to Nernst equation [10], the conversion relationship between the equilibrium electrode potential and the standard electrode potential is as …show more content…
It can be known the relationship between the temperature and the equilibrium electrode potential from eq.(1) that when the temperature rises, the equilibrium electrode potential increases. At the same time, the warm temperature makes the electrolyte activity increase. Both sides accelerate the cathode reduction and crystallization of metal ions.
Considering the change on interfacial energy, the most conducive shape to form the two-dimensional nucleus is the cylinder. Suppose that the cylinder nucleus, radius r and height h, is the same high to an atomic, then the variation of critical free energy that formed the two-dimensional crystal nucleus of the metal atoms and stably existed is ∆G_c. If the cathode overpotential is very serious, ∆G_c could be expressed as [11]:
∆G_c=(πhσ^2 A)⁄(ρn_0 Fη_c )
The interaction between laser and liquid substance generates a series of mechanics-electric effect, thermoelectric effect and photoelectric effect, which will affect the grain nucleation, surface topography and the reduction reaction rate of the deposition. According to Nernst equation [10], the conversion relationship between the equilibrium electrode potential and the standard electrode potential is as …show more content…
It can be known the relationship between the temperature and the equilibrium electrode potential from eq.(1) that when the temperature rises, the equilibrium electrode potential increases. At the same time, the warm temperature makes the electrolyte activity increase. Both sides accelerate the cathode reduction and crystallization of metal ions.
Considering the change on interfacial energy, the most conducive shape to form the two-dimensional nucleus is the cylinder. Suppose that the cylinder nucleus, radius r and height h, is the same high to an atomic, then the variation of critical free energy that formed the two-dimensional crystal nucleus of the metal atoms and stably existed is ∆G_c. If the cathode overpotential is very serious, ∆G_c could be expressed as [11]:
∆G_c=(πhσ^2 A)⁄(ρn_0 Fη_c )