高温合金粉末内部孔洞的研究概况

Investigation of Porosity in Superalloy Powder

阐述了等离子旋转电极工艺 (PREP)制取的镍基高温合金粉末内部孔洞的形成机理 ,分析了导致孔洞形成的因素 ,提出了降低粉末内部孔洞应采取的措施。研究结果表明 :孔洞的尺寸随着粉末粒度的下降而减小。在相同雾化制粉工艺参数条件下 ,粗粉中孔洞的数量多于细粉。随着棒料转速的提高 ,空心粉数量增加。此外 ,雾化室内混合惰性气体压力降低或混合惰性气体中氩气含量提高 ,均能使空心粉数量降低。

The formation mechanism of porosity in Ni base superalloy powder produced with PREP was stated. Some factors of porosity forming were analyzed. And some quality control techniques for decreasing porosity amount were presented. It was showed that the porosity size decreases with decreasing powder size. With the same atomized parameters, the porosity amount in large size powder is more than that in small size powder. The porosity powder amount increases with increasing rotating speed of rod. The amount of porosity powder can be decreased by decreasing pressure of inner gas mixture in atomizing chamber and increasing argon content in inner gas mixture.