A Study on Internal Defects of PREP Metallic Powders by Using X-ray Computed Tomography

In this study, the distribution, proportion and characteristics of internal defects in three kinds of powders of Ti-6Al-4V, 316-steel and Co-29Cr-6Mo alloys, produced by the plasma rotating electrode process (PREP) at various rotation speeds, are characterized by using both scanning electron microscopy (SEM) and synchrotron X-ray computed tomography (CT). The results show that in the powder of a given alloy, internal pores are formed more easily in coarse particles than in fine powder during PREP. The proportion of powder with pores can be reduced by appropriately increasing the rotation speed. In addition, the composition of an alloy has a great influence on the defect formation.