Heat treatment effects on Mg–Zn–Ag–xCa alloys: a study on corrosion resistance and antimicrobial activity in simulated physiological conditions

Abstract

This study aims to investigate the effects of heat treatment on the corrosion resistance and antimicrobial activity of Mg–Zn–Ag–xCa alloys under simulated physiological conditions. The focus of this research is to understand how to optimize the biomedical performance of the alloy by adjusting its composition, particularly its stability in simulated body fluids and its ability to counteract microbes. The corrosion behavior and antibacterial properties of silver-containing magnesium alloys with different calcium contents after solution treatment were studied. The results show that the addition of calcium affects the microstructure of the alloy, including grain refinement and the distribution of the second phase. It acts as a barrier at the microscopic scale, which helps to prevent the invasion of the corrosive agent, thereby improving the overall corrosion resistance of the material. The gradual increase in calcium initially has a positive effect on the properties of the alloy, especially in terms of corrosion resistance. However, when the calcium content increases to 1.5Ca, although the initial corrosion potential of the alloy increases, excessive calcium may lead to excessive accumulation of the second phase in the microstructure, which will have a negative impact on the long-term stability and corrosion resistance of the material. After corrosion, when the calcium content is 1.0 wt%, the surface roughness of the sample is 1.65 μm, with the surface being the smoothest, and the corrosion rate is 0.25 mm·year⁻¹. However, when the calcium content increases to 1.5 wt%, the sample exhibits the fastest corrosion rate at 0.45 mm·year⁻¹. The antibacterial properties of magnesium alloy were optimized by adding silver.

Graphical abstract