Oxidation behavior of TaNbHfTiZr coatings prepared by double glow plasma surface alloying technique

To enhance the reliability of tungsten in high-temperature applications, TaNbHfZrTi coatings were deposited on tungsten surface using the double glow plasma surface alloying technique. The microstructure and oxidation resistance of TaNbHfTiZr coatings prepared at different alloying temperatures were systematically investigated. The oxidation behavior of the developed coatings was assessed through exposure to air at 800 °C for 10 h. The physical phase composition, microscopic morphology, and elemental distribution of the coatings were systematically characterized using scanning electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction. The results indicate that the coatings exhibit a single body-centered cubic solid solution phase, with their microstructure, mechanical properties, and oxidation behavior significantly influenced by the processing temperature. Among these, the H900 coating exhibits excellent overall performance, achieving a Vickers hardness of 829 ± 11 HV under a 9.8 N load—significantly higher than that of the pure tungsten substrate (approximately 500 HV). Furthermore, its oxidation resistance is significantly enhanced, with a unit area weight gain of only 4.95 mg/cm2 after 10 h of oxidation at 800 °C, which is far lower than that of the tungsten substrate.