Preparation and Properties of Thick Tungsten Coating Electrodeposited from Na2WO4-WO3-KCl-NaF Molten Salt System

The pulsed current electrodeposition method was employed for the first time to achieve tungsten coating with a thickness of 433.72 μm on a CuCrZr alloy from Na2WO4-WO3-KCl-NaF molten salt. The microstructure of the coating was observed and the coating density, porosity, hardness, bonding strength, residual stress and oxygen content were tested. The results revealed that the tungsten coating exhibited desirable characteristics such as high density, absence of impurities, excellent adhesion to the matrix (53.16 MPa), residual compressive stress as surface stress, and good stability and durability. Moreover, this thick tungsten coating possesses high density and hardness, low oxygen content and porosity. This offers a novel solution to solve the challenging issue of the connection between tungsten material and heat sink material.