Mg–Ca–Zn bio-degradable light alloys produced in a levitation induction melting furnace

Abstract

A new generation of Mg-based metallic alloys appears to be particularly promising in the field of biocompatible materials. These alloys have a controlled biodegradability in biological or living fluids. In this paper, nine Mg–Ca–Zn alloys with different chemical compositions were produced and analysed. The production of magnesium alloys by conventional technologies invariably introduces impurities from the refractory lining, which is not permitted in medical systems to be implanted into the human body. During levitation melting, the metal is maintained inside the inductor at a certain distance from the coil, avoiding the contact with any other material, by the action of induction currents. The induction currents cause the mixing of the chemical elements inside the melt, providing the homogeneity of the alloy. The alloys were produced in the levitation induction melting furnace under controlled atmosphere. By combining the effects generated by the magnetic field created in metallic parts, there was possible to hold, heat and melt solid material inside a specifically designed inductor fed by a medium frequency converter. The EDS analysis revealed the chemical compositions, and microhardness tests HV_0.1 and microstructural analysis were performed in order to establish the hardening effects and the homogenization degree of the solid solutions.