Influence of binder concentration on morphology of Porosity-graded hydroxyapatite ceramics |
Paper ID : 1286-UFGNSM-FULL (R1 |
Authors: |
Abstract: |
This paper describes the slip casting process of Porosity-graded hydroxyapatite ceramics in the presence of tiron (1, 2-Dihydroxybenzene-3, 5-disulfonic acid disodium salt hydrate) as a dispersant and polyvinyl alcohol as a binder. Zeta potential measurements conducted on hydroxyapatite powder suspensions demonstrated that suspensions with pH >7 had better stability, and addition of 2wt% PVA did not influenced the isoelectric point remarkably. The suspensions stability and the appropriate amount of tiron were determined by measuring of sedimentation heights. HAP slurries with 10wt% solid loading, 1.9wt% dispersant and different amount of PVA were casted in plaster slabs. Finally, samples were dried in 105℃ and subsequently sintered at 900℃. Investigation on morphology and pore size distribution was carried out by SEM. It was found that addition of PVA could improve mechanical strength of green body and porosity volume; however, it could deteriorate porous structure by importing cracks during debinding and sintering phases. |
Keywords: |
porous hydroxyapatite, slip casting, binder effect. |
Status : Paper Accepted (Poster Presentation) |