Corrosive Wear Behavior Of Zn In NaCl Solution And NaOH Solution

Zinc has been widely used in steel surface coating for protesting the corrosion of the steel substrate.However,it's tribocorrosion behavior in corrosive medium is not well investigated.In this thesis,the corrosion wear behavior of zinc in 0.5M NaCl solution and 0.5M NaOH solution was studied.In addition,uniform and compact hydrophobic films on zinc were prepared by molecular self-assembly technique.The wettability and corrosion wear properties of the films were investigated and discussed.The experiments are in progress with certain results.(1)Under open circuit,the potential of Zn in 0.5M NaCl solution moves towards the cathode,and its corrosion resistance is weakened.In the process of friction in 0.5M NaCl solution,the polarization curve obtained by potentiodynamic scanning shows no passivation zone.However,the passive region can be clearly observed without friction..(2)In the 0.5M NaOH solution,the potential moves towards the anode,and the corrosion resistance increases.Even in the case of large load and high frequency reciprocating sliding,the obvious passivation zone can still be observed in the polarization curve,which shows that the passivation ability of Zn in 0.5M NaOH solution is very strong.The passivation film formed by Zn in 0.5M NaOH solution is uniform and dense,and has strong corrosion resistance,but it is not wear resistant.This result in larger wear rate when passivation film is formed rapidly in passivation zone.Correspondly,the friction coefficient increases with the increase of potential.(3)It is found that the ZnO film with uniform and packed nanorod structure is firstly created by oxidizing the zinc substrate.The as-fabricated surface was then coated by a layer of stearic acid.The resulting surfaces have a water contact angle as high as150° and the rolling angle is less than 5°.The super-hydrophobic film which prepared on zinc substrate has excellent corrosion resistance performance and friction-reducing and antiwear properties when they are used in 0.5M NaCl solution.