Microstructure and thermal property of tungsten coatings prepared by vacuum plasma spraying technology

In the present work, tungsten coatings were deposited by vacuum plasma spraying technology and their microstructure and composition were characterized using SEM, XRD, TEM and EDS. Some basic properties of tungsten coating were detected and the thermal property of the coating was focused. The obtained results showed that the tungsten coating was consisted of well-melted particles overlapped each other and exhibited typical lamellar microstructure. Pores in line and irregular shapes and interfaces between layers were also observed. The thermal diffusivity of the as-received tungsten coating was about 47.7 mm2 s−1, which was lower than that of bulk tungsten. Gradient interlayer composed of tungsten and copper improved the bonding strength between the tungsten coating and copper alloy substrate.