In-vitro corrosion behavior and mechanical properties of biodegradable Zn alloys designed for gastrointestinal anastomosis

The degradation behavior and the decay of the mechanical performance of Zn-0.45Mn and Zn-0.45Mn-0.4Li alloys in simulated intestinal fluid (SIF) were investigated. The Zn-0.45Mn-0.4Li alloy, which was made of Zn phase, MnZn13 phase, and LiZn4 phase with the addition of Li element, degraded more quickly than the Zn-0.45Mn alloy. The two Zn alloys in SIF had comparable corrosion models, and the corrosion products fell off periodically. With an elongation (EL) of 57.8% and an ultimate tensile strength (UTS) of 391 MPa, Zn-0.45Mn-0.4Li had outstanding mechanical properties compared with Zn-0.45Mn. The LiZn4 phase that formed in the Zn-0.45Mn-0.4Li alloy as a result of the inclusion of Li element had a pinning effect that increased the alloy strength. When the Zn alloys were submerged in SIF, their EL gradually reduced as the immersing duration increased, but their UTS stayed mostly constant. Zn-0.45Mn-0.4Li had 396 MPa UTS and 29.7% EL after 90 days of immersion. Cytotoxicity test proved that Zn-0.45Mn-0.4Li had excellent biocompatibility. Zn–Mn–Li alloys had promising potential for gastrointestinal anastomosis.