Experimental investigation of the effect of binder type on the mechanical properties of the product in binder jetting type 3D printer

Binder jetting technology is an additive manufacturing method. In this technology, powders are bonded with a liquid binder selectively sprayed on a powder bed. This process is repeated layer by layer until the final part is produced. Many powdered raw materials, including various ceramics, metals, polymers, can be used to produce parts with this method. At the same time, it is one of the methods that has come to the fore in recent years due to its features such as the absence of residual stresses when there is no heat input during the production phase, and the possibility of colorful and fast production. In this study, it is aimed to obtain successful results by providing a strong bond with different types of binders (powder and liquid) of HA (Hydroxyapatite) material, which cannot be produced with the Binder jetting method. As raw material, HA (Hydroxyapatite) was used in powder form. PVA (Polyvinyl Alcohol) and Acrylic were used as powder binders. These materials were mixed with powdered HA powders at 20%, 30% and 40% by weight. In addition, two different materials, HP45 cartridge containing 98% water and ZB10 Binder, were used as binders. In total, samples were produced with 6 different powder mixtures and 2 different liquid binders. For the samples produced by the Binder Jetting method before sintering, the term green part is used in the literature. In this study, sintering was not performed after the samples were produced. All tests and analyzes were performed on the green part. Microstructures of the produced samples were examined by SEM and XRD analysis. The relative density value of the samples was 90% on average and it was observed that the prosthesis had an irregular and amorphous structure. Productions made with acrylic could not give the expected results, and remained at very low strengths compared to PVA. In addition, when the HP 45 liquid binder and ZB 10 binders were compared, it was observed that the ZB10 binder provided a stronger bond and was more successful in dissolving the powder binders than HP45. In the compression test results made on the samples produced with the ZB10 variation used as a liquid binder with a mixture of 60%HA and 40% PVA, it was determined that it was the variation with the most rigid and highest strength.