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, which would broaden the application range of molybdenum and alloys thereof. However, traditional methods for preparing TiB₂ coatings have disadvantages such as high equipment costs, complicated processes, and highly toxic gas emissions. This paper proposes an environmentally friendly method, which requires inexpensive equipment and simple processing, for preparing TiB₂ coating on molybdenum via electrophoretic deposition within Na₃AlF₆-based molten salts. The produced TiB₂ layer had an approximate thickness of 60 µm and exhibited high density, outstanding hardness (38.2 GPa) and robust adhesion strength (51 N). Additionally, high-temperature oxidation experiments revealed that, at 900°C, the TiB₂ coating provided effective protection to the molybdenum substrate against oxidation for 3 h. This result indicates that the TiB₂ coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.