Abstract
This study aimed to determine the effects of how powder degrades in quality from use in the laser powder bed fusion (L-PBF) process and investigate what changes in the powder cause defects in finished parts. It was determined that the reused powder affected the finished part quality, resulting in an increased number of lack-of-fusion (LOF) pores. This was due to a change in the size distribution of the powder particles, characterized by an increase in larger sizes and a significant decrease in smaller sizes. There was an 11% increase in defective particles over the five prints that went through the sieving process, as well as an increase of ~2% of particles >63μm, resulting in less powder that could be reused after each print. The results enabled the determination of the life of the powder due to the degradation of the powder from the differing property changes caused by the reuse of the powder.