Research On The Process And Properties Of Ni-P Alloy By Electroplating

Electroplating and chemical plating are the two methods of making Ni-P coating. But because of several advantages, electroplating technology is wider used than chemical plating.Electric plating is a kind of fast electric deposition process based on traditional electroplating, which has high deposition speed, coating quality etc. In this paper, the process experiments of Ni-P coating were finished on the self-developed NC electric plating machine, and the performance tests were finished as well.Firstly, based on theoretical knowledge, FLUENT and ANSYS were used to simulate the flow field and the electric field in the electric plating processing area. Determine the final anode nozzle structure through contrastive analysis between the single-phase flow model and the multiphase flow mode with FLUENT. Finally, analyze the effects of different flow rate and dipolar gap on the flow field. Additionally, analyze the distribution of cathode current density under the static condition via ANSYS software to study the effects of different voltage and dipolar gap on it. Also, simulate the coating growth under the condition of voltage 22v and dipolar gap 1.Omm.Secondly, utilize the response surface method to study the effects of voltage、 electrolyte temperature、dipolar gap and dipolar relative velocity on deposition rate、surface roughness and surface hardness, establishing the regression equation and selecting the optimal process parameters of each equation. Finally, the optimal process parameters were obtained, that is, voltage 21V、electrolyte temperature 64℃、dipolar gap 0.8mm and dipolar relative velocity 395 mm/min. Under these conditions, the results of response surface tests are:deposition rate 60.68 μm/min、the surface roughness 0.315μm and the surface hardness 714.79HV. There was only Ni and Ni3P in the coating after heat treatment of 400℃, which is tested by XRD.Finally, the relationship of between process parameter and endurance of Ni-p coating was studied as well as analyzing the effects of heat-treatment temperature on hardness and endurance of Ni-p coating. According to the wear topography by SEM, the wear mechanism was also obtained.