Influence of high-temperature ECAP on the structure and mechanical properties of a biodegradable Zn-Cu-Mn alloy for medical implants

Abstract

Problem. Currently used materials for ureteral stents are unable to eliminate inflammation, exhibit low strength, and require a second surgery for removal. Metallic bioresorbable stents can reduce the burden on the patient’s body and eliminate additional operations for product removal. Aim. To roduce a new biocompatible Zn-1 %Cu-1 %Mn alloy and, using equal-channel angular pressing at elevated temperature, to develop an improved set of mechanical properties for potential application as a material for ureteral stents. Methods. The Zn-1 %Cu1 %Mn alloy was subjected to equal-channel angular pressing at 200 °C (8 passes, route Bc). The microstructure and elemental composition were studied using transmission electron microscopy with energy-dispersive analysis. Mechanical properties were evaluated under uniaxial tension (strain rate of 10–3 с –1 , at least 3 samples per each condition), Vickers microindentation with construction of hardness distribution maps, and fractographic analysis of fracture surfaces using a scanning electron microscope. Results. By indexing diffraction patterns, it was established that the deformation processing promotes the precipitation of MnZn13 phase particles, which may have a strengthening effect. Fractographic analysis of fractured samples after tension showed a change in the fracture character from brittle to ductile with deep dimples. Carrying out equal-channel angular pressing (ECAP) for 8 passes at elevated temFrontier Materials & Technologies. 2026. № 1 17 Абдрахманова Э.Д., Хафизова Э.Д., Поленок М.В. и др. «Влияние высокотемпературного РКУП на структуру и механические…» peratures allowed increasing the ultimate tensile strength by 2.3 times, the offset yield strength by 3 times, and the percentage elongation by 8 times. The distribution of microhardness values becomes more uniform with a n increase in passes from 2 to 8, and the gap between the smallest and largest values decreases. Conclusions. It was established that the deformation method (ECAP, 8 passes) for the new biocompatible Zn-1 %Cu-1 %Mn alloy develops an improved set of mechanical properties, which opens up possibilities for its application in medical purposes.