Effect of Si addition on microstructure and properties of magnesium alloys with high Al and Zn contents

In order to assess the possibility of using magnesium alloys with high Al and Zn contents as degradable fracturing balls, the effects of Si addition on microstructures, mechanical properties and degradable behavior of Mg-17Al-5Zn (mass.%) alloy were investigated. The results show that the minor Si addition can refine α-Mg matrix and modify Mg2Si particles. With the increase of Si content, the yield strength of the alloys initially increases and reaches to the maximum 309 MPa in alloy containing 0.5 wt % Si. The degradable corrosion rate exhibits an inverse trend and reaches the maximum in alloy containing 3 wt % Si with 0.46 mm/day at 298 K and 5.39 mm/day at 366 K, respectively.