Ying-Long Zhou

Microstructures, mechanical and corrosion properties and biocompatibility of as extruded Mg-Mn-Zn-Nd alloys for biomedical applications

Extruded Mg-1Mn-2Zn-xNd alloys (x=0.5, 1.0, 1.5 mass %) have been developed for their potential use as biomaterials. The extrusion on the alloys was performed at temperature of 623K with an extrusion ratio of 14.7 under an average extrusion speed of 4mm/s. The microstructure, mechanical property, corrosion behavior and biocompatibility of the extruded Mg-Mn-Zn-Nd alloys have been investigated in this study. The microstructure was examined using X-ray diffraction analysis and optical microscopy. The mechanical properties were determined from uniaxial tensile and compressive tests. The corrosion behavior was investigated using electrochemical measurement. The biocompatibility was evaluated using osteoblast-like SaOS2 cells. The experimental results indicate that all extruded Mg-1Mn-2Zn-xNd alloys are composed of both α phase of Mg and a compound of Mg7Zn3 with very fine microstructures, and show good ductility and much higher mechanical strength than that of cast pure Mg and natural bone. The tensile strength and elongation of the extruded alloys increase with an increase in neodymium content. Their compressive strength does not change significantly with an increase in neodymium content. The extruded alloys show good biocompatibility and much higher corrosion resistance than that of cast pure Mg. The extruded Mg-1Mn-2Zn-1.0Nd alloy shows a great potential for biomedical applications due to the combination of enhanced mechanical properties, high corrosion resistance and good biocompatibility.

Microstructures and mechanical properties of as cast Mg–Zr–Ca alloys for biomedical applications

Abstract The microstructures and mechanical properties of as cast Mg–Zr–Ca alloys were investigated for potential use in biomedical applications. The Mg–Zr–Ca alloys were fabricated by commercial pure Mg (99·9 mass-%), Ca (99·9 mass-%) and master Mg–33 mass-%Zr alloy. The microstructures of the alloys were examined by X-ray diffraction analysis and optical microscopy, and the mechanical properties were determined from tensile tests. The experimental results indicate that the Mg–Zr–Ca alloys with 1 mass-%Ca are composed of one single α phase; these alloys with 2 mass-%Ca consist of both Mg2Ca and α phase, and all the alloys exhibit typical coarse microstructures. An increase in Zr increases the strength of Mg–Zr–Ca alloys with 1 mass-%Ca, and the formation of Mg2Ca decreases the strength of the alloys. Mg–1Zr–1Ca alloy (mass-%) has the highest strength and best ductility among all the studied alloys.

Influence of extrusion on the microstructure, mechanical properties and in vitro corrosion performance of biodegradable Mg-1Mn-2Zn-1Nd alloy

Mg-1Mn-2Zn-1Nd alloy (mass %) has been developed for use as a hard tissue implant material. As-cast Mg-1Mn-2Zn-1Nd alloy exhibited a good biocompatibility and mechanical properties. To improve the corrosion performance and mechanical strength of the Mg-1Mn-2Zn-1Nd alloy, the hot extrusion was applied on this alloy. The influence of extrusion process on the microstructure, mechanical properties and in vitro corrosion performance of Mg-1Mn-2Zn-1Nd alloy has been investigated by X-ray diffraction analysis, optical microscopy, scanning electron microscopy, uniaxial tensile and compressive tests, electrochemical and immersion measurement. The experimental results show that the extrusion can significantly refine the microstructure of Mg-1Mn-2Zn-1Nd alloy, resulting in the improvement of mechanical properties and corrosion performance. The extrusion process does not alter the corrosion mechanism of a Mg alloy.