Structural and thermal investigations of the ternary Mg–Zn–Ca system

Abstract

Magnesium alloys have become suitable candidates for potential biomedical materials due to their excellent mechanical properties, biocompatibility, and biodegradability. Among different Mg alloys, the Mg–Zn–Ca system is the most popular degradable implant material. The aim of this work is the structure and thermal investigation of the ternary Mg66Zn30Ca4 alloy by a high-energy ball milling process for 5, 8, 13, and 20 h. Morphology changes (SEM) and phase analysis (XRD) of searching materials were investigated. The morphology of the obtained powders and the chemical composition were examined using a scanning electron microscope (SEM) with the energy-dispersive spectrometer (EDS). The distribution of powder size of the samples was determined using the laser particle size analyzer. The thermal characteristics of the powders have been investigated up to 450 °C by differential scanning calorimetry (DSC). Additionally, a microhardness test was carried out. The XRD diffraction patterns of powders show the presence of a solid solution of αMg and the Mg51Zn20 phase. The characteristic Bragg lines of unreacted Zn and Ca can be observed in addition. The DSC analyses showed phase transformations taking place in the alloy. SEM analysis showed a lamellar morphology, which is the result of the deformation process within milling. The results of the microhardness (HV0.05) measuring showed that increasing the milling time improved the microhardness of the Mg66Zn30Ca4 alloy.