This work allowed the study and comparison of the cooling rate, surface morphology, and microstructure of nickel-based super-alloy powders produced by the atomization of argon and nitrogen. The results show that the principal phase in argon and nitrogen atomized powders has an FCC structured γ-phase with γ′-strengthening phase. X-ray diffraction detected no apparent nitride or oxide on the powder surface. The interplanar spacing and lattice constant of γ-phase increase as the powder size decreases. Nitrogen- and argon-atomized powders are spherical, but argon- atomized powders have higher sphericity and smoother surfaces. Atomization by argon has produced a small number of satellite particles, whereas atomized nitrogen powders have more split particles. The proportion of special-shaped powder decreases with the decreasing powder particle size. The super-alloy powder with high sphericity can be effectively obtained by controlling the particle size. Because of the higher coefficient of thermal expansion, the trough of argon-atomized powders is higher than that of nitrogen-atomized powders with the same particle size. As the powder particle size decreases, the hollowness of the powders declines for both powders, with the argon- atomized powder falling more quickly. The cooling rate of melted alloy droplets has an essential effect on the surface characteristics of the powder. The dendrite morphology of argon-atomized powders is more evident than that of nitrogen-atomized powders. As the powder particle size decreases, the radial dendrites gradually disappear, with dendrites and cellular crystals dominating the powder surface. The cooling rate of the powder is calculated based on the surface secondary dendrite arm spacing. It is found that argon-atomized powders exhibit cooling rates from 2.09 × 10⁴ K ∙ s^–1 to 1.26 ∙ 10⁵ K ∙ s^–1, while nitrogen-atomized powders show higher cooling rates in the range between 2.71 ∙ 10⁴ K ∙ s^–1 and 1.86 ∙ 10⁵ K · s^–1. Because of the higher cooling rate, nitrogen- atomized powders have a lower secondary dendrite arm spacing than argon-atomized powders with similar particle sizes.

这项工作可以对氩和氮雾化产生的镍基高温合金粉末的冷却速率、表面形貌和微观结构进行研究和比较。结果表明，氩氮雾化粉末的主相为FCC结构的γ相，其中含有γ′强化相。X射线衍射检测到粉末表面没有明显的氮化物或氧化物。随着粉末尺寸的减小，γ相的晶面间距和晶格常数增大。氮雾化粉末和氩雾化粉末都是球形的，但氩雾化粉末具有更高的球形度和更光滑的表面。氩气雾化产生少量卫星颗粒，而雾化氮粉则产生更多分裂颗粒。随着粉末粒径的减小，异形粉末所占的比例也随之减小。通过控制粒度可以有效地获得高球形度的高温合金粉末。由于热膨胀系数较高，相同粒径的氩雾化粉末的波谷高于氮雾化粉末。随着粉末粒径的减小，两种粉末的粉末空心度均下降，其中氩雾化粉末下降得更快。熔化合金熔滴的冷却速率对粉末的表面特性具有重要影响。氩雾化粉末的枝晶形态比氮雾化粉末更明显。随着粉末粒径的减小，放射状枝晶逐渐消失，粉末表面以枝晶和蜂窝状晶体为主。粉末的冷却速率是根据表面二次枝晶臂间距计算的。研究发现，氩雾化粉末的冷却速率为 2.09 × 10⁴ K ∙ s ^–1至 1.26 ∙ 10 ⁵ K ∙ s ^{–1 ，而氮雾化粉末在 2.71 ∙ 10 4} K ∙ s ^–1和 1.86 ∙ 10 ⁵ K ∙ s ^–1范围内表现出更高的冷却速率。由于冷却速率较高，氮雾化粉末比具有相似粒径的氩雾化粉末具有更低的二次枝晶臂间距。