Microstructure, Mechanical Properties, and Antibacterial Performance of Novel Fe-Mn-Zn Nanocrystalline Alloys Produced by Mechanical Alloying

This study investigates the impact of zinc (Zn) content on the microstructure and mechanical properties of (70-x)Fe-30Mn-xZn (x = 0, 3, 6, and 9 wt%) nanocrystalline alloys produced using mechanical alloying and subsequently formed into pellets through hot pressing and sintering. X-ray diffraction analysis indicates that Fe-30Mn-xZn (x = 0, 3, 6, and 9 wt%) particles exist in the austenite phase. According to scanning electron microscopy/energy-dispersive X-ray spectroscopy results, elemental distribution is homogeneous. Density tests of consolidated samples are performed by the Archimedes method. Among the tested alloys, the Fe-30Mn-9Zn alloy shows the highest relative density at 94.21%. Additional tests are performed to evaluate hardness, wear resistance, bending strength, corrosion behavior, and antibacterial properties. The Fe-30Mn alloy has the highest hardness and wear resistance with a 548.66 HV value, which can be attributed to the solid solution hardening mechanism. The Fe-30Mn-9Zn alloy displays a bending strength of 1277.61 MPa and the lowest corrosion rate of 0.044 mm year-1 with potentiodynamic polarization tests, attributed to low porosity. Antibacterial tests conducted using the colony counting method with Staphylococcus aureus and Escherichia coli bacteria show that increasing the zinc content significantly enhances the antibacterial properties of the alloy.