【摘要】 采用超高转速等离子旋转电极法（Supreme-speed plasma rotating electrode process,SS-PREP）和氩气雾化法（Argon atomization,AA）制备了球形EP741NP合金粉末，对比研究了两种制粉方法对粉末特性的影响。结果表明，采用SS-PREP法制备的EP741NP合金粉末形貌更加规则，空心粉和异形粉含量更低，在氧增量、球形度及流动性等物理性能方面具有明显优势，但粉末粒径较大；AA法制备粉末中不规则颗粒较多，粉末颗粒表面有较多卫星粉，部分粉末之间存在粘连。SS-PREP法制备的EP741NP合金粉末颗粒表面为典型枝晶组织，且呈放射状生长；AA法制备的粉末颗粒表面组织不清晰，局部可观察到少量枝晶，粉末中存在较多空心粉颗粒以及个别组织异常粉末，空心粉内部孔洞被完全封闭，孔洞内部并非光滑表面，呈棉絮状且形状不规则，主要是由于雾化气体的冲击导致液膜破碎不完全，雾化气体被裹入，在袋状液膜闭合前，内部雾化气体没有逸出，进而形成空心粉。在室温、650℃和750℃测试条件下，SS-PREP和AA两种不同方法制备的EP741NP合金拉伸性能均表现出相同的规律，SS-PREP法粉末的拉伸强度和屈服强度优于AA法粉末。更多还原

【Abstract】 Spherical EP741 NP alloy powders were prepared by the supreme-speed plasma rotating electrode process(SS-PREP) and argon atomization(AA) process. A comparative study was conducted to investigate the effects of the two powder preparation processes on the powder characteristics. The results show that the EP741 NP alloy powders prepared by the SS-PREP process have a more regular morphology, lower contents of hollow powders and irregularly shaped powders, and obvious advantages in physical properties such as oxygen pickup, sphericity and fluidity, but with a larger powder particle size. The powders prepared by the AA process contain more irregular particles, with many satellite particles on the surface of the powder particles, and adhesion between some powders. The surface of the EP741 NP alloy powder particles prepared by the SS-PREP process exhibits a typical dendritic structure that grows in a radial pattern. The surface structure of the powders prepared by the AA process is unclear, a small amount of dendrites can be observed locally, and there are more hollow powder particles and individual powders with abnormal microstructures in the powders. The internal pores of the hollow powders are completely enclosed, and the inner surface of the pores is not smooth, showing a flocculent and irregular morphology. This phenomenon is mainly attributed to the incomplete breakup of the liquid film caused by the impact of the atomizing gas; The atomizing gas gets entrapped, and the internal atomizing gas does not escape before the pouch-shaped liquid film collapses, thereby forming hollow powders. At the test temperatures of room temperature, 650 ℃ and 750 ℃, the tensile properties of the EP741 NP alloys fabricated from the two types of powders exhibit consistent trends in tensile properties, with the tensile strength and yield strength of the powders prepared by the SS-PREP method higher than those prepared by the AA process.更多还原