Superficial Modification of the Mg–Zn Biomaterials via Ion Nitriding for Biomedical Applications

Abstract

In the present work, the powder metallurgy (PM) technique was used to synthesize biocompatible alloys Mg95–Zn5, Mg90–Zn10, and Mg85–Zn15 (wt %) under an argon atmosphere that employed stainless-steel vessels and spheres with a milling treatment of 360 rpm during 15 h. The obtained powder was consolidated through a sintering process for subsequent ion nitriding treatment to increase its corrosion resistance and hardness. The synthesized alloys analyzed by Scanning electron microscopy (SEM) images showed a reduction in particle size with increasing grinding time. The X-ray diffraction (XRD) results showed the formation of a MgZn intermetallic phase and, furthermore, that no impurities were found during the grinding process. The surface-modified Mg–Zn alloys showed some improvement in terms of corrosion (Ecorr 26% and Icorr 13%) and microhardness (HV 40%) compared to Mg. Cytotoxicity evaluation was conducted via an MTT ((3-(4,5-DIMETHYLTHIAZOL-2-YL)-2,5-DIPHENYLTETRAZOLIUM BROMIDE)) assay, which revealed that the Mg–Zn alloys and nitrided samples did not exhibit cytotoxicity towards fibroblast cells after 96 h.