Electrodeposition of Fine-Grained Tungsten Coatings on CuCrZr Alloy Substrates from Relatively Low Temperature KF-KCl-WO3 Molten Salt System

To address the issue in the pure oxide molten salt system Na2WO4-WO3, where the relatively high melting temperature often causes thermal corrosion of the base material and reduces electrodeposition efficiency. A new molten salt system for electrodeposition tungsten coatings on CuCrZr substrates at relatively low temperatures was investigated. The crystal structure and microstructure of the tungsten coatings were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The results indicate that the power supply mode, current density, and duty cycle significantly affect the microstructure, crystalline characteristics, and overall performance of the tungsten coating. Pure tungsten coatings were successfully fabricated on CuCrZr substrates at 943 K. The best electrodeposition parameters were determined to be a current density of 40 mA/cm2 and a duty cycle of 40%. Moreover, after prolonged electrodeposition (60 h), the tungsten coatings retained fine grains, with sizes ranging from 2 μm to 6 μm.