Effect of Multidirectional Forging on Microstructure, Mechanical Properties and Corrosion Behavior of Biodegradable Zn-۰.۵Mg Alloy

The effect of multi-pass multidirectional forging (MDF) was investigated on the microstructure, mechanical properties, and corrosion behavior of the Zn-۰.۵Mg biodegradable alloy. According to the results, multi-pass MDF effectively modified the as-cast microstructure through the fragmentation of coarse dendrites, crushing and more uniform distribution of Mg۲Zn۱۱ intermetallic particles, closure of microporosities, and the formation of ultrafine grains with a crystallite size of about ۱۰.۶ nm. The yield and ultimate shear strengths of the ۵-pass MDFed sample were found to be higher than those of the as-cast, ۱-pass, and ۳-pass MDFed samples by ۴۲%, ۲۶%, and ۱۴%, and ۱۶%, ۸%, and ۲%, respectively. However, following a ۱۰% improvement in the ۱-pass MDFed sample, the normal displacement of the Zn-۰.۵Mg alloy decreased to about ۰.۴۵ mm/mm in the ۵-pass MDFed sample. The corrosion resistance of the as-cast alloy in SBF solution was improved by factors of ۱.۴ and ۲.۷ after ۱ and ۳ passes of MDF passes, respectively, despite the fact that alloying zinc with ۰.۵ wt.% Mg caused a considerable decrease in the corrosion resistance.

کلیدواژه ها:

Zn-۰.۵Mg alloy ، Biodegradable ، Multidirectional forging ، Mechanical properties ، Corrosion behavior