Process Of Electroless Ni-P Plating On Zr-Al Alloy

Electroless plating is widely used, which belongs to the electroless deposition method,the electrodeposition compared, low requirement on equipment, the operation is verysimple, the obtained coating is excellent, is widely used in various fields. It is an effectiveway to improve the corrosion-resistance of the Zr-Al alloy that electroless plating Ni-P onit.Therefore, research on chemical nickel plating has quite important practical value.The bath components are various and the plating parameters are complex,but themost important is the main salt, reductants, complex agents, temperature and pH value.And the influence is mainly on the solution stability and deposition rate. Using theperpendicularity experiment, observing the base, XRD, SEM, EDS, and micro-rigidity, westudied the effect of the component and structure of Zr-Al in the process, the influence ofplating parameters on Zr-Al, and the feature of the plating structure.This study is to get the Ni-P alloy coating on the surface of Zr-Al alloys whichcontent8.8wt%and8.0wt%Al by electroless plating.In the experiments, Zr-Al alloysneed to be pre-treatmented,and the pretreatments are ultrasonic cleaning,alkalinedegreasing,pickling and activating.Then,they can be electroless plated by different platingbath.And the plating bath include strong acidic and weak acidic.At last,they wereexamined by XRD,morphology both the surface and section and electrochemicalpolarization.It is found that10-20μm amorphous Ni-P alloy coating can be got bydifferent plating bath,and the coating is to be cellular under the microscope.A good platingcoat can be got on the8.0wt%Al Zr-Al alloy by phosphating which has a temperature of50℃,pH is2.5and with the time of4minutes. Ni-P alloy coating can improve thecorrosion-resistance of the matrix, it has a good protection for the Zr-Al alloy.Metal surface should have certain activity can electroless plating, and the metalsurface activity is determined by three factors, including plating liquid reducing agent,properties of metal surface and the reducing agent and the effect of metal surface. Thereaction steps, the reaction mechanism of electroless plating nickel to make furtherresearch, to explain the experimental data in the experiment phenomenon.