A Ni-Al-Cu coating was prepared on NAB alloy through electroplating and heat treatment, and the erosion-corrosion behaviors were investigated. The results demonstrated that Ni-Al-Cu coating exhibited higher erosion resistance compared to NAB alloy, with an average reduction of 63 % in material removal rate (MRR). It was revealed that deformation and cracks were observed in NAB, with loss of hard κ and β phases alongside deformation of ductile α phase. Meanwhile, Ni-Al-Cu coating experienced fatigue delamination and grain disintegration due to alternating stress. Taguchi design method showed that increasing flow velocity and sand concentration could enhance the intensity of gravel impact, while changes in the erosion angle affected gravel impact modes and energy transfer, thereby impacting corrosion performance. Additionally, empirical equations for the material removal rate were derived through regression analysis, which became possible to predict the MRR under different influencing factors and assess the erosion-corrosion resistance of materials.
Jinyu Pi,Mengjin Chen,Tianqi Chen,Qi Wang,Shijian Cheng,Chaoyang Fu
A combined experimental and theoretical study was performed on corrosion inhibition effect of 1-Phenyl-5-mercaptotetrazole (PMT) on nickel-aluminum bronze (NAB) in seawater . Gravimetric measurement and electrochemical method, such as the open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), Tafel polarization curve were used to verify the corrosion inhibition effect of PMT. It was found that the corrosion inhibition efficiency (IE) of PMT achieved 94.4 %, 99.5 %, 98.7 % at a concentration of 1.12 mM, respectively. The slump of the degree of corrosion on NAB surface was also revealed based on SEM and AFM images analysis with the addition of PMT. According to the Langmuir isotherm model based on EIS, PMT was confirmed as a mixed-type corrosion inhibitor between −20 kJ mol –1 and −40 kJ mol –1 . Besides, the successful adsorption of PMT on NAB has been revealed by the results of XPS and the change of water contact angle on NAB surface. In combination XPS with quantum chemistry calculations, PMT molecules are adsorbed on the surface of NAB by the active S atom and the tetrazole ring as the major adsorption groups, thus, the protective barrier formed by PMT on the surface of NAB can effectively insulate NAB from contact with seawater. The research results in this paper have showed that PMT as a drug intermediate has an excellent corrosion inhibition effect on the NAB at extremely low concentration in seawater.