Processing and microstructure of bioresorbable Zn/Mg multi-materials manufactured by additive friction stir deposition

Abstract

This work explores the development of novel Zn/Mg multi-materials for biomedical applications by leveraging the complementary properties of Mg (bone-matching elastic modulus, rapid degradation) and Zn (moderate strength, slower degradation rate). Additive friction stir deposition, a solid-state manufacturing process, is used to manufacture Zn/Mg multi-materials. Microstructural analysis reveals a well-defined three-layer interface structure consisting of a mixture of Mg + MgZn, nm-sized grains of MgZn₂, and nm-sized grains of Mg₂Zn₁₁ phases from the Mg side to the Zn side. The interface region was fully dense, free of cracks, and showed substantial capability of plastic accommodation which was able to relieve stress concentrations through different mechanisms. These findings highlight the potential of additive friction stir deposition to control the thickness and structure of the Zn/Mg interface and pave the way for the manufacturing of Zn/Mg multi-material components for biomedical applications.