Structure and mechanical properties of biodegradable magnesium alloy MA14 subjected to ECAP-Conform

Abstract

The application of biodegradable materials in the development of innovative medical techniques for restoring lost functions in patients is one of the priority areas in the field of medical materials science. One such material is the magnesium alloy designated as MA14, which possesses biocompatibility but exhibits low strength and increased brittleness during processing, complicating its use for manufacturing medical implants. It is known that the application of intensive plastic deformation principles in the design of thermomechanical processing is one of the modern approaches to enhance the comprehensive properties of metallic materials by significantly modifying the initial structure to an ultrafine-grained or nanocrystalline state. An example of implementing such an approach is the Equal Channel Angular Pressing by Conform scheme (ECAP-C). This study investigates the influence of ECAP-C technological parameters on the structure and mechanical properties of the magnesium alloy MA14. Experimental research was conducted using the ECAP-C setup with variations in the number of cycles and processing temperature. The analysis of structural studies' results from laboratory samples revealed the occurrence of dynamic recrystallization processes and significant structure refinement from 50±10 μm in the initial state to 5±3 μm after 6 ECAP-C cycles with a stepwise temperature reduction. Mechanical testing of samples in this structural state indicates a noticeable increase in the tensile strength and yield strength to 330±7 MPa and 250±5 MPa, respectively. The relative elongation during tensile testing amounted to 28±1%.