Surface properties of Al2O3-YSZ ceramic composites modified by a combination of biomimetic coatings and electric polarization

Abstract Alumina-containing yttria-stabilized zirconia composite (Al-YSZ) has a higher flexural strength than YSZ, although Al-YSZ cannot directly bond with bone tissues. To expand the biomedical applications of Al-YSZ, new surface modifications were investigated to improve the bioactivity in the present study. The combination of a biomimetic coatings method using an alternate soaking technique and electric polarization treatment was performed on Al-YSZ. The crystalline phases of the starting Al-YSZ sintered disks were assigned to tetragonal ZrO 2 and α-Al 2 O 3 phases. The analyses of the electrical properties were carried out using complex impedance and thermally stimulated depolarized current measurements for polarization treatments. Our results indicate that the stored charges in Al-YSZ via polarization decreased in YSZ, because of the added alumina, while the calcium phosphate film deposited by the biomimetic coatings method on polarized Al-YSZ was observed to be thicker than the non-polarized film. The coating method would be suitable for the complex geometry of biomaterials. As a result, polarized Al-YSZ fabricated using an alternate soaking process is expected to be useful as a biomaterial under load-bearing conditions.