Influence of particle size distribution on hydroxyapatite slurry and scaffold properties fabricated using digital light processing

In order to clarify the mechanism of particle size distribution in DLP printing process of HA ceramics, five groups of HA slurries with different particle size distributions were prepared, and the effect of particle size distribution on the performance of HA slurry and printed HA samples was systematically studied. The results demonstrated that increasing the content of nano HA powder enhances the stability of the HA slurry. However, this also led to an increase in excess curing width due to intensified scattering during the curing process. In terms of the performance of the sintered samples, due to the higher sintering activity of nano powder, the increase of nano HA content from 0 % to 40 % promoted the linear shrinkage of the sample size in the x, y, and z directions, and increased the density of the sintered parts by 13.25 %, the compressive strength by 21.36 %, and the flexural strength by 81.14 %.