Fabrication and Characterization of Biodegradable β-TCP/Zn-Ag-Based Composites via AgNWs-Assisted Hetero Agglomeration and SPS-Induced In Situ Alloying

Biodegradable Zn-based composites reinforced with bioactive ceramics, featuring enhanced mechanical performance, moderate corrosion rates, significantly improved biocompatibility, and specific biological functionalities, are promising candidates for biomedical implant materials. However, achieving uniform dispersion of nano-scale ceramic particles within a metallic matrix and ensuring robust interfacial properties between the bioceramic and metallic matrix remain challenging. In this study, homogeneous dispersion of beta-tricalcium phosphate (β-TCP) reinforcement within the Zn matrix was achieved through hetero-agglomeration, using silver nanowires (AgNWs) as a bridging agent. Additionally, spark plasma sintering (SPS)-induced in situ alloying between Ag and Zn resulted in strong interfacial bonding between the β-TCP reinforcement and the AgZn3 secondary phase in the β-TCP/Zn-Ag biocomposites. The Vickers hardness significantly increased from 48.2 HV for pure Zn to 70.0 HV for 1β-TCP/Zn-Ag biocomposites. Consequently, the biodegradable 1β-TCP/Zn-Ag composite, manufactured through the AgNWs-assisted hetero-agglomeration method and subsequent SPS and HE processes, could serve as a desirable orthopedic implant material. This work offers an innovative and creative approach for the development of advanced Zn matrix biocomposites.