Concurrence of High Corrosion Resistance and Strength with Excellent Ductility in Ultrafine-Grained Mg-3Y Alloy

Abstract

In the field of magnesium-based degradable implantable devices, the Mg-Y-RE-Zr alloying system (WE-type) has gained popularity due to its satisfying degradation rate together with mechanical strength. However, utilization of RE and Zr in the WE-type alloys was originally driven to improve Mg-based alloys for high-temperature applications in the industry, while for medical purposes, there is a question of whether the amount of alloying elements may be further optimized. For this reason, our paper presents the Mg-3Y (W3) magnesium alloy as an alternative to the WE43 alloy. This study shows that the omission of RE and Zr elements did not compromise the corrosion resistance and the degradation rate of the W3 alloy when compared with the WE43 alloy; appropriate biocompatibility was preserved as well. It was shown that the decrease in the mechanical strength caused by the omission of RE and Zr from the WE43 alloy could be compensated for by severe plastic deformation, as achieved in this study, by equal channel angular pressing. Ultrafine-grained W3 alloy exhibited compression yield strength of 362 ± 6 MPa and plastic deformation at maximum stress of 18 ± 1%. Overall, the early results of this study put forward the motion of avoiding RE elements and Zr in magnesium alloy as a suitable material for biodegradable applications and showed that solo alloying of yttrium is sufficient for maintaining desirable properties of the material at once.

Microstructure and Corrosion Resistance of AZ91 Magnesium Alloy after Surface Remelting Treatment

“…Magnesium alloys are modern metallic materials, which, due to their good strength properties and low density (1.74-2.0 g/cm 3 ), are increasingly more frequently an alternative for steel and aluminum alloys. This is because the density of those alloys is lower by one-third than that of aluminum alloys and almost 80% lower than the density of steel [1].…”

“…This is because the density of those alloys is lower by one-third than that of aluminum alloys and almost 80% lower than the density of steel [1]. In addition, magnesium alloys stand out owing to their good thermal conductivity, good biocompatibility, low heat capacity, excellent machinability and sound damping capabilities and good casting properties, including castability, as well as the possibility of complete recycling [2][3][4]. Despite the unique properties of magnesium alloys, a serious obstacle to their expansion is their low corrosion resistance, which is one of the main causes of the failure of components made of magnesium alloys.…”

Corrosion and Mechanical Behavior of Metal Materials

“…Many high-strength metal-related materials and structures work under the coupling condition of harsh corrosion environments and complex loading [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17], and related failure cases have been reported extensively all over the world. Hence, it is absolutely essential to investigate the corrosion and mechanical behavior of metal materials, aspects which mainly include corrosion fatigue [3][4][5], stress corrosion cracking [6][7][8], erosion corrosion [9], hydrogen-induced cracking [10], wear corrosion [18], etc.…”