Microstructure, mechanical properties and corrosion properties of Mg-4Zn-xNi alloys for degradable fracturing ball applications

In order to find suitable degradable materials for the fracturing ball of wolf howl, a new as-cast Mg-4Zn-xNi (x = 0.5, 1, 2, 4 wt.%) alloys were prepared. Results indicated that the addition of Ni element lead to the formation of Mg2Ni phase in the Mg-4Zn-xNi alloys, which responsible for the increase of compressive strength and micro-hardness of Mg-Zn series alloy. Nevertheless, formation of Mg2Ni phase with high electrochemical potential can also accelerate the degradation rate of Mg-Zn series alloy. Accompanied with the increasing Ni content, the amount of Mg2Ni phase increases simultaneously, which aggravate galvanic corrosion and results in the higher degradation rate of Mg-Zn series alloys. The Mg-Zn-Ni alloy with moderate strength and higher degradation rate are obtained in present work, which is thought as an ideal candidate for the fracturing ball of wolf howl. (C) 2019 Elsevier B.V. All rights reserved.