Effect of addition of Si on microstructure, mechanical properties, bio-corrosion and cytotoxicity of Mg-6Al-1Zn alloy
(Department of Materials Science and Engineering, Faculty of Mechanical Engineering, Babol Noshirvani University of Technology, P. O. Box 47148-71167, Shariati Street, Babol, Iran)
Abstract: The Mg-6Al-4Zn alloy was fabricated by mechanical alloying (MA) and hot pressing to serve as biodegradable metal implant. The influence of addition of 1% Si (mass fraction) on the microstructure, mechanical properties and bio-corrosion behavior of Mg-6Al-1Zn alloy was studied using X-ray diffractometry, transmission electron microscopy, compression test, as well as immersion, electrochemical test and MTT assay. The results showed that the addition of 1% Si to Mg-6Al-1Zn alloy led to the formation of fine Mg2Si phase with polygonal shape, and increased compressive strength, elongation and improved corrosion resistance. Furthermore, the cell viability of Saos-2 cells has been improved by addition of 1% Si to Mg-6Al-1Zn alloy. According to the results, the magnesium ions released in the methylthiazol tetrazolium (MTT) test have not shown any cell toxicity. All these indicated that the addition of 1% Si improved the properties of Mg-6Al-4Zn alloy for using as a biodegradable implant.
Key words: Mg-based alloy; mechanical alloying; mechanical properties; corrosion rate; cell viability