High-temperature oxidation resistance of TiB2 coatings on molybdenum produced by molten salt electrophoretic deposition

TiB2 coatings can significantly enhance the high-temperature oxidation resistance of molybdenum, and then broaden the application range of molybdenum and its alloys. Traditional methods of preparing TiB2 coatings are featured with some disadvantages such as high equipment cost, complicated process, and highly toxic gas emissions. Herein, a method characterized by its low equipment cost, simple process, and being friendly toward environment for preparing a TiB2 coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts was proposed. The produced TiB2 layer was around 60 µm in thickness and it exhibited high density, hardness (38.2 GPa), and robust adhesion strength (51 N). Additionally, experiments of high-temperature oxidation revealed that at 900 °C, the TiB2 coating provided effective protection against oxidation of the molybdenum substrate for a period of 3 h. This result indicated that the TiB2 coating, prepared on molybdenum using the molten salt electrophoretic deposition approach possessed good high-temperature oxidation resistance.