The Effect of Zr Addition on Microstructures and Hardness Properties of Zn-Zr Alloys for Biodegradable Orthopaedic Implant Applications

Abstract

Abstract The development of Mg and Fe based biomaterials in the past decade has been extensively studied as biodegradable material for medical applications. The development of this material is limited in terms of its suitability for clinical applications. Zn-based alloys began to be an alternative to be studied as a substitute for Mg and Fe based biomaterials. Zn-based alloys have a moderate degradation rate but have low mechanical properties, so other elements need to be added to improve their mechanical properties. In this study, the added element is zirconium (Zr) with a composition variation of 0.5%, 1%, and 2%. The alloying method used was casting with a temperature of 550°C. The results of the microstructure analysis, the addition of Zr to Zn alloys will form precipitates in the side of the grain boundaries and more addition of Zr composition, the smaller grain size formed. The grain size from pure Zn until the addition of 2% Zr in the sequence are 266.40 µm, 20.16 µm, 16.70 µm, and 15.85 µm. The XRD analysis, from the addition of Zr, will form the Zn phase and the intermetallic phase Zn22 Zr. The hardness value obtained from pure Zn until 2% Zr in the sequence are 35.162 HV, 41.988 HV, 42.324 HV, 57.112 HV.