The Effects of T4 and T6 Heat Treatment on the Corrosion Behavior of MgZnCa Alloys

Abstract

Some of the most important characteristics of a medical implant biomaterial are its corrosion resistance, cytotoxicity, mechanical property, and overall biological performance. Optimizing these characteristics is therefore vital to the success of creating effective medical biomaterials. It is well known that heat treatment processes affect the microstructure of metallic alloys which consequently can have favorable influences on the mechanical properties. The determination of the effects of heat treatment on the corrosion resistance of metallic alloys is another aspect that must be examined. That is the goal of this investigation. The corrosion characteristics of two MgZnCa alloy systems (MgZnCa-31 and MgZnCa-32) were studied to determine the correlation between T4 and T6 heat treatment and the corrosion rate on the alloys. The alloys were produced by melting and casting at 730°C and then heat treated. The corrosion performances of the alloys were examined by both immersion and electrochemical analysis, which were conduct in 0.9% NaCl physiological saline solution. In terms of the effects of the T4 heat treatment, the corrosion rate of the MgZnCa-31 decreases as the time period of the heat treatment increases, whereas the MgZnCa-32 alloys have an opposite effect meaning that the corrosion rate increases as the time period of the heat treatment increases. There was no significant change in corrosion with the introduction of T6 heat treatment to both alloy systems.