Characterization of a Zn-Ca₅(PO₄)₃(OH) Composite with a High Content of the Hydroxyapatite Particles Prepared by the Spark Plasma Sintering Process

• Main Authors: Jan Pinc, Jaroslav Čapek, Jiří Kubásek, Filip Průša, Vojtěch Hybášek, Petr Veřtát, Ivona Sedlářová, Dalibor Vojtěch
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: Metals
• Subjects: metal-matrix composites; biodegradable materials; sintering
• Online Access: https://www.mdpi.com/2075-4701/10/3/372

Zinc and zinc alloys have been studied due to their corrosion properties as potentially biodegradable materials. In this study, a zinc/hydroxyapatite composite (Zn/HA) containing 16 wt % HA was prepared by spark plasma sintering and characterized in detail. The microstructure, mechanical and corrosion properties were studied and the mutual relations between properties and microstructure were found. The porosity was evaluated to be approximately 18%. The mechanical properties (ultimate compression strength = 65 MPa and ultimate flexural strength = 120 MPa) are sufficient for the potential scaffolding and augmentation of cancellous bone. The flexural properties of these materials were measured for the first time. Immersion tests and subsequent analyses confirmed no direct participation of hydroxyapatite in the corrosion process and an ideal corrosion rate of approximately 0.4 mm/year. The amount of released zinc was between 4−6 mg/day corresponding with the maximal usable surface area of 25 cm². All the results suggest that the Zn/HA composite is suitable as a potential biodegradable material (from the point of view of mechanical and corrosion properties) for the replacement of cancellous bones.