Fabrication and properties of a stable and porous YSZ/nano-HA structure by binder jetting processes

ABSTRACT

In the preparation of porous ceramic structure by binder jetting process, the stability and strength of porous ceramic structure caused by different powder composition have attracted much attention. Therefore, a pore filling method was proposed in this paper, in which nano-hydroxyapatite (nano-HA) particles with different contents were filled into yttrium-stabilized zirconia (YSZ) ceramic powders to solve the poor porosity and weak mechanical properties of porous ceramic structure. The effects of nano-HA content on the pore formation, surface quality, phase stability, compressive strength and microstructure of porous YSZ/nano-HA structure were studied. The results showed that as the mass percentage of nano-HA increased to 25 wt.%, the surface roughness of the top, side, and bottom decreased, whereas the relative density increased from 39.3% to 48.8%. After sintering at 1450°C the porous YSZ/nano-HA structures revealed a decrease in shrinkage (18.1% −11.5%) and water absorption (4.4% −2.3%), but an increase in compressive strength (30.9 MPa − 41.2 MPa). The sintered phase of YSZ/nano-HA structure presented a new microstructure evolution process, in which t-ZrO₂ and Ca₃(PO₄)₂ acted as the main crystal phase, with trace amounts of Ca_0.15Zr_0.85O_1.85 cubic solid solution.

KEYWORDS:

• 3D
• porosity
• ceramics
• sintering
• density
• binder jetting
• strength
• morphology

Acknowledgements

The authors thank the National Natural Science Foundation of China (Grant No. 51375190) and the major project of Guangdong Provincial Department of Science and Technology (Grant No. 2017B010124002) for the financial support.

Disclosure statement

No potential conflict of interest was reported by the author(s).