This study investigated the effect of the type of gas used, nitrogen and helium, during cold spraying of titanium coatings. In all conditions, the propelling gases' temperature and pressure were attuned to attain three similar particle velocities for each gas. Coatings were characterized by SEM and XPS. Deposition efficiency, coating microhardness, and porosity were evaluated for all conditions. Results show that for the same particle impact velocity, the deposition efficiency and coating density were mostly the function of the surface temperature, which in turn was influenced by spray parameters. It is shown that loosely-bonded particles at the surface can be detached by the passage of high pressure supersonic gas stream. In addition, a thick and fully dense cold sprayed titanium coating was achieved with optimized spray parameters with He and the corresponding average particle velocity was measured at 1173 m/s.
展开▼
机译：这项研究调查了钛涂层冷喷涂过程中使用的气体类型（氮气和氦气）的影响。在所有条件下，对推进气体的温度和压力进行微调，以使每种气体达到三个相似的粒子速度。通过SEM和XPS表征涂层。在所有条件下评估沉积效率，涂层显微硬度和孔隙率。结果表明，对于相同的粒子撞击速度，沉积效率和涂层密度主要是表面温度的函数，而表面温度又受喷涂参数的影响。结果表明，通过高压超音速气流的通过，可以使表面松散结合的颗粒脱离。另外，使用优化的He喷涂参数获得了厚而密实的冷喷涂钛涂层，相应的平均粒子速度为1173 m / s。
展开▼
