Study On The Microstructure By Maskless Localized Electrodeposition Based On Simulation Of Electric And Flow Fields

Maskless localized electrochemical deposition is a new microstructure technology based on the traditional electrochemical deposition technology and organically combines the characteristics of metal 3D printing.It adopts the forming methods of point into line,line into layer,layer upon layer,which can produce complex metal micro and nano structures with little internal stress,no thermal deformation,no crack defects,etc.Thus maskless localized electrochemical deposition has become a research hotspot in recent years.However,due to the large number of parameters involved in this process and their interaction,it requires too much energy and material resources to study it through experiments.With the development of computer technology,the study of maskless localized electrochemical deposition based on numerical simulation has become an effective and convenient means.In this paper,the main research contents include the basic theory of maskless localized electrochemical deposition,the analysis of electric field and flow field simulation in maskless localized electrodeposition,multiphysics simulation research on maskless localized electrodeposition.And micro-nickel column was deposited under different parameters to investigate the specific effects of flow field and electric field on manufacturing microstructure by maskless localized electrodeposition.The electric field of maskless localized electrochemical deposition was simulated,and the process was simulated by COMSOL Multiphysics software.The influence of different anodic shapes and sizes on the deposition layer was analyzed.The influence of different process parameters(voltage,duty cycle)on the process of maskless localized electrochemical deposition was simulated by using needle-like electrode geometry model.Then,a local electrodeposition flow field model without mask was established to analyze the changes of flow pattern in the initial stage of deposition and deposition process,and the deposition effect under each flow pattern was explored through experiments.Finally,a hydroelectric coupling model is constructed to study the relationship between the electeode gap and the flow field.The results show that the needle electrode is easier to operate and has better deposition effect than other electrodes.The diameter of nickel column increases with the increase of voltage,but the change of duty ratio has little effect on the diameter of nickel column.At different flow rates,the motion state of the plating solution flowing to the cathode is different,and the morphology of the micro-nickel column deposited is different.When the voltage of droplet,micro droplet and micro jet increases,the diameter of nickel column increases.In the impinging jet state,the diameter of micro-nickel column increases first and then decreases.The top of the electrodeposited micronickel column under the impinging jet condition shows an obvious sharp cone shape,and there are often slender "burrs" around the micronickel column.The electric field gradually diffuses outward from the tapered anode and shows a descending trend in steps.The voltage at the center of the cathode decreases with the increase of the distance between the poles.Under the condition of microjet,the machining effect is better when the electrode gap is 25μm.