Effects of duty cycle on properties of Ni–P–Al2O3 nanocomposite deposited layer prepared by pulse-assisted jet electrochemical deposition

Abstract

In order to improve the surface quality of the nanocomposite deposited layer, the pulse technology was introduced to the jet electrochemical deposition process, and the Ni–P–Al2O3 nanocomposite deposited layer was successfully prepared. By changing the pulse duty cycle to prepare the composite deposited layer and comparing it with the Ni–P–Al2O3 composite deposited layer prepared under the DC condition and the Ni–P deposition layer prepared under the condition of better pulse duty cycle, the influence of pulse duty cycle on its related performance is explored. In this study, SEM, metallurgical microscope, XRD and EDS were used to analyze the surface morphology, section morphology, phase and composition of Ni–P–Al2O3 deposited layers under different experimental conditions. The hardness and elastic-plastic mechanical properties of the nanocomposite deposited layer were evaluated by hardness tester and nanoindentation tester, and the corrosion resistance of the deposited layer was evaluated by electrochemical workstation. The results showed that the Al content in the deposition layer first increases and then decreases with the increase of the pulse duty cycle, and reaches the highest level of 1.77 wt% when the pulse duty cycle is 60%. The surfaces of the deposited layers prepared under this condition were uniformly dense with better corrosion resistance and the highest hardness value reached was 817.4 HV. At the same time, the elastic recovery ratio he/hmax reached the maximum with a value of 0.36, and the resistance to deformation reached the best.

Keywords

• Jet electrochemical deposition
• Pulse duty cycle
• Microhardness
• Corrosion resistance
• Resistance capacity to deformation