Exploring Electrochemical Direct Writing Machining of Patterned Microstructures on Zr702 with Polyacrylamide Polymer Electrolyte

Zirconium alloys possess excellent wear resistance, which ensures the durability and longevity of the components, making them widely used in medical and other fields. To enhance the functionality of these materials, it is often necessary to fabricate functional microstructures on their surfaces. Electrochemical machining (ECM) techniques demonstrate excellent machining performance for these metals, particularly in the processing of microstructures on complex curved surfaces. However, ECM often faces challenges due to the fluid nature of the electrolyte, resulting in low machining accuracy and localization. This paper proposes a novel method for fabricating complex patterned microstructures using a maskless electrochemical direct writing technique with a polyacrylamide (PAM) polymer electrolyte. By leveraging the non-Newtonian properties of PAM, this method effectively confines the electrolyte to specific areas, thus addressing the issue of poor localization in traditional ECM and reducing stray corrosion. To elucidate the electrochemical removal mechanism of Zr702 in the presence of PAM, polarization curves, viscosity characteristics, and current efficiency parameters were analyzed. Additionally, an experimental study was conducted using a custom-designed nozzle structure. The results showed that the PAM electrolyte could effectively reduce the EF, positively impacting machining accuracy and localization. By controlling the nozzle's motion trajectory, complex microstructures were successfully fabricated through direct writing, demonstrating promising application prospects.