Influence of irradiation parameters on the curing and interfacial tensile strength of HAP printed part fabricated by SLA-3D printing

In this paper, the curing and the interfacial tensile strength of a hydroxyapatite (HAP) printed part, fabricated by stereolithography (SLA), are systematically evaluated. First, a stable HAP paste was developed with a viscosity suitable for SLA-3D printing. In the curing process of SLA-3D printing, an evident laser removal phenomenon occurred on the upper surface of the cured HAP paste, which was not mentioned in other studies. Therefore, the influence of irradiation parameters on the curing characteristics of HAP paste was investigated, while a modified critical laser exposure inequation was established, to derive the curing range of HAP paste under a UV spot. Next, the influence of irradiation parameters on the interfacial tensile strength of HAP printed part was tested and analyzed in detail. Ideally, the laser removal site formed on the cured surface would increase the contact area with the next layer and facilitate a stronger mechanical bond between layers.