Study on a Novel Biodegradable and Antibacterial Fe-Based Alloy Prepared by Microwave Sintering

Abstract

This research produced a porous Fe-8 wt.% Cu alloy by microwave sintering in order to achieve (i) an increased biodegradation rate, and (ii) an antibacterial function. The Fe-8Cu alloy had higher density, hardness and degradation rate (about 2 times higher) but smaller and fewer surface pores, compared to the pure Fe. The Fe-8Cu alloy had a strong antibacterial function (the antibacterial rates against E. coli were up to 99.9%) and good biocompatibility. This work provides a novel approach of alloy design and processing to develop novel antibacterial Fe-based alloys.

Comparative Study on Biodegradation of Pure Iron Prepared by Microwave Sintering and Laser Melting

“…As depicted in Figure 6b, the surface biodegradation products contained O, Fe, Ca and P. In the present work, MSed Fe showed higher biodegradation rates than LMed Fe; these two had higher biodegradation rates than the as-cast Fe. The biodegradation rate was closely related to the compactness of the materials with the porous structure, as substantiated by previous studies [13,25,26]. The porous structure increased the actual area of the contact surface between the materials and the solution.…”

“…The biodegradation was studied using a potentiodynamic polarization test and an immersion test, which were performed in Hank's solution (containing 8.00 g/L NaCl, 0.40 g/L KCl, 0.10 g/L MgCl 2 •6H 2 O, 0.35 g/L NaHCO 3 , 0.10 g/L MgSO 4 •7H 2 O, 0.14 g/L CaCl 2 , 0.12 g/L Na 2 HPO 4 •12H 2 O, 0.06 g/L KH 2 PO 4 , and 1.00 g/L glucose) with a pH of 7.6 at 37 ± 0.5 • C. More details of the potentiodynamic polarization test and the immersion test have been documented elsewhere [13,14]. Corroded surfaces and topographic maps were observed by a SEM (ZEISS EVO-18, Jena, Germany) and a 3D measuring laser microscope (Barcelona, Spain) after the immersion test, separately.…”

“…Corroded surfaces and topographic maps were observed by a SEM (ZEISS EVO-18, Jena, Germany) and a 3D measuring laser microscope (Barcelona, Spain) after the immersion test, separately. The degradation rate, P i (mm/year), was calculated from the potentiodynamic polarization test using Equation (1) [13], and the degradation rate, P w (mm/year), was calculated from immersion test using Equation (2) [14].…”

“…In addition, microwave sintering and laser melting are net-shape manufacturing techniques, which may produce patient-specific implants with minimal post-processing and shorter lead time compared to conventional manufacturing methods such as casting. So far, both microwave sintering and laser melting have been successfully used to produce iron in biomedical applications [13,14]. However, these studies mostly focused on processing or comparing novel manufacturing methods or alloys to conventionally manufactured pure iron.…”

Microstructural, Mechanical and Corrosion Characteristics of Degradable PM Biomaterials Made from Copper-Coated Iron Powders

“…People have fabricated various binary iron-based systems containing silver [ 5 , 6 , 7 ], copper [ 7 , 8 , 9 ], or zinc [ 10 , 11 ], the most common alloying elements with good antibacterial properties, though often without any intention to produce self-disinfecting products.…”