Abstract:Most hulls of the ships are protected with paintings, sacrificial anode, and impressed current cathodic protection methods against corrosion problems. However, these conventional methods are not very effective because the rudder of ships stern are exposed to very severe corrosive environment such as tides, speeds of ships, cavitations and erosion corrosion. The environmental factors such as cavitation and corrosion will cause damage for materials with the shock wave by the creation and destruction of bubble. To solve these problems, the cavitation and electrochemical experiments are executed for thermal spray coating with Al−Zn alloy wire material. Thereafter, and sealed specimens with F−Si sealer on Al−Zn alloy coated specimen are executed to improve electrochemical and anti-cavitation characteristics in sea water. The application of fluorine silicon sealing after spray coating of 15%Al−85%Zn seems to be appropriate not only in static environment but also in dynamic environment.

Key words: cavitation; Al−Zn alloy wire material; thermal spray coating; corrosion