低阴极沉积电位对铝合金表面硅烷膜层的影响

EFFECTS OF LOW CATHODIC POTENTIAL ON ELECTRODEPOSITED SILANE FILMS ON ALUMINUM ALLOY

在低阴极沉积电位条件下,使用表面活性剂改性硅烷溶液,实现了双-1,2-[γ(三乙氧基)硅丙基]四硫化物(BTSPS)在铝合金电极表面的电化学沉积,新的临界沉积电位(NCCP)约为-1.6 V.研究表明,在低阴极沉积电位下铝合金表面能得到更厚、更致密的硅烷膜层,并且在改性后溶液中制备的膜层具有较高的极化阻力.表面活性剂的加入可以降低沉积时析氢的影响,提高硅烷沉积性能.临界沉积电位的降低,使得硅烷覆盖的铝合金电极比临界沉积电位(-0.8 V)下的电极具有更好的抗腐蚀性能.

Bis-1,2-[triethoxysilylpropyl]tetrasulfide （BTSPS） films have been successfully deposited at low cathodic potential in silane solution modified by surfactant, and a new critical cathodic potential （NCCP） （-1.6 V） has been found. The study indicated the surface morphology of silane films prepared at low cathodic potential were more compact and thicker than those prepared at conventional critical cathodic potential （-0.8 V）,and BTSPS films prepared at low cathodic potentials in modified silane solution exhibited obviously higher corrosion resistances in comparison with silane films prepared by conventional electrodeposition method. Hydrogen evolution could be decreased as well as the electrodeposition of silane could be improved while adding the surfactant. Anti-corrosion of films is better as well as a negative shift of the critical cathodic potential.