Quantitative Characterization of Superalloy Powder Particle Shape Using Dynamic Image Analysis Technique

Eight shape parameters were selected to qualitatively and quantitatively characterize the particle shape of superalloy powders using field emission scanning electron microscopy (FE-SEM) and dynamic image analysis (DIA) technique. The results show that Krumbein sphericity (SPHT_K), aspect ratio (AR), compactness (Compct) and Krumbein roundness (RDNS_C) demonstrate a significant distinction degree of superalloy powder particle shape, and can be used as critical parameters for the characterization of particle shape. In addition, the distinction degree of circularity (C), sphericity (SPHT) and SPHT_K increases gradually. In particular, the SPHT_K has the highest distinction degree among the three shape parameters. By comparing the difference in distinction degree among eight shape parameters, it is found that the distinction degree of circularity (C), sphericity (SPHT), convexity (Conv_A) and solidity (Solid) is not significant. Therefore, the SPHT_K, AR, Compct and RDNS_C are selected as the shape parameter combination to quantitatively characterize the particle shape. The combination of these four shape parameters can be used to quantitatively characterize the change of superalloy powder particle shape. Meanwhile, it provides a data basis to effectively optimize the atomization processing parameters. The promotion of the development of additive manufacturing and advanced powder metallurgy technology in future was discussed in the end.