Effect of nano-HA content on the mechanical properties, degradation and biocompatible behavior of Mg-Zn/HA composite prepared by spark plasma sintering

• Published in: Materials characterization 2019-05, Vol.151, p.620-631
• Main Authors: Cui, Zeqin, Li, Weijian, Cheng, Linxin, Gong, Dianqing, Cheng, Weili, Wang, Wenxian
• Format: Article
• Language: English
• Subjects: Biodegradable Mg-based composite; Corrosion behavior; Cytotoxicity evaluation; Spark plasma sintering (SPS)
• ISSN: 1044-5803; 1873-4189
• DOI: 10.1016/j.matchar.2019.03.048

Recently, Mg-Zn alloy had been investigated as biodegradable material for fabricating orthopedic implants. In this paper, nano-hydroxyapatite (nano-HA) [Ca10(PO4)6(OH)2] was uniformly distributed on the surface of magnesium particles by ball milling process, and then the composite of Mg-5.5Zn/HA was successfully fabricated by spark plasma sintering (SPS). Effect of the nano-HA content on the compressive strength and the bioactivity in vitro (corrosion behavior, cytotoxicity) of the composite was analyzed. Results indicated that with the increasing of the nano-HA content (from 0 to 10 wt%), the compressive yield strength is improved remarkably. Comparing with Mg-5.5Zn alloy, of the nano-HA (10 wt%) can improve the compressive yield strength by 43% and bending strength by 14%. Furthermore, the in-vitro immersion tests revealed the positive and negative effects of nano-HA content on the corrosion behavior of Mg-5.5Zn/HA composite. The nano-HA can improve the degradation resistance of the Mg-5.5Zn matrix. Addition of 10 wt% HA can decrease the corrosion rate by 49%. Furthermore, the composite exhibits acceptable cytotoxicity to L-929 cells, and impressive potential to be used as an orthopedic implant material. •The high density and completely solid solution Mg-5.5Zn/HA composite was successfully fabricated by Spark plasma sintering (SPS).