Correlation Between Microstructure, Mechanical Properties, and Corrosion Characteristics of AZ31 Mg Alloy Processed by Accumulative Roll Bonding Process

In this work, the effect of the accumulative roll bonding (ARB) process on the microstructure, mechanical properties, and corrosion characteristics of AZ31 Mg alloy was investigated. First, the ARB process up to 3 cycles at 350 degrees C was applied to annealed AZ31 Mg alloy sheets. Then, all samples were characterized via microstructure observations, mechanical investigations, and also, electrochemical analyses, and immersion tests in simulated body fluid (SBF) solution. In addition, the L929 cell line was used to evaluate the cytotoxicity of the samples. The obtained results showed that after the third ARB cycle, the average grain size in the annealed sample decreased from similar to 14 to similar to 3 mu m. Some ultra-fine grained (UFG) microstructures that had a grain size of fewer than 1 mu m were also observed in the 3-cycle ARB-processed sample. This grain refinement led to an increase in the yield strength and micro-hardness values of the annealed sample from similar to 153 MPa, and similar to 55 Hv to similar to 214 MPa, and similar to 76 Hv. However, the ARB process had an adverse effect on the corrosion characteristics of samples, and the corrosion rate increased after the ARB process. Moreover, the viability of L929 cells in culture media containing extracts obtained from the annealed sample was higher than that for the 3-cycle ARB-processed sample after 3 days of incubation. The influence of microstructural evolution in the ARB-processed AZ31 Mg alloy on the corresponding mechanical properties, corrosion behaviors, and cytotoxicity results was discussed in detail.

Automated summary

The effect of the accumulative roll bonding (ARB) process on the microstructure, mechanical properties, and corrosion characteristics of AZ31 Mg alloy was investigated. The ARB process led to a decrease in grain size and an increase in yield strength and micro-hardness values. However, it also had an adverse effect on the corrosion characteristics of the samples.