Degradation Behavior and Mechanical Properties of Porous Biodegradable FeMnC Alloys Produced by Powder Metallurgy for Biomedical Applications

Abstract

The advent of biodegradable implants represents a landmark orientation in the biomedical field toward a new generation of medical devices, offering improved patient outcomes, and eliminating the need for subsequent surgeries. FeMn alloys are well-established as promising candidates for such applications. This study analyzes the microstructure, mechanical properties, and degradation behavior of FeMnC alloys produced via pressing and sintering process using water-atomized FeMnC powder. To investigate the impact of pore size and volume fraction on the mechanical properties and degradation rates, two groups of FeMnC samples were prepared, one compacted at 600 MPa (CP 600) and the other at 700 MPa (CP 700). In addition, pure Fe samples compacted at 600 MPa and prepared using the same methodology were used as a reference. Chemical analysis carried out on both the pre-alloyed powder and the resulting sintered samples (CP 600 and CP 700) revealed a significant reduction in the amount of Mn, O, and notably C after sintering. The pure Fe group showed the greatest mechanical strength with an average tensile rupture strength of 446 ± 24 MPa. Among the three groups, CP 600 exhibited the highest degradation rate (−0.339 ± 0.057 mmpy) after 14 days of static immersion degradation test in modified Hanks' solution, demonstrating a degradation behavior characterized by mass gain.