关键词: 镍铝介金属镀膜, 坑蚀, 动电位极化

Abstract: A cathodic arc plasma ion plating process was demonstrated to deposit Ni_Al film on AISI 1045 carbon steel to evaluate the cavitation protection. Three target materials with Ni52Al48, Ni60Al40, and Ni70Al30 compositions were used to reveal the microstructural of coatings. Experimental results show that the nickel content in these deposits increased with the nickel content of the target material. The major phase of deposited film was Ni3Al regardless of the target materials. All of the as_deposited films presented very strong adhesion and reflects their cavitation erosion behavior in fresh water. All coatings increased the cavitation erosion resistance of the bare substrate 10 fold. These coatings also enhanced the cavitation resistance 2_fold or greater in 3.5 wt.% NaCl and 3_fold in 3.5 wt.% HCl electrolyte. The potentiodynamic polarization data of coated specimens in these two electrolytes indicated that the coated specimens exhibited higher corrosion potential and lower corrosion current density than the bare substrate material. It is believed that the cavitation erosion induced pitting corrosion into the substrate accelerated the mass loss rate of the substrate.