Alloying and Processing Effects on the Microstructure, Mechanical Properties, and Degradation Behavior of Extruded Magnesium Alloys Containing Calcium, Cerium, or Silver

Abstract

Magnesium alloys attract attention as degradable implant materials due to their adjustable corrosion properties and biocompatibility. In the last few decades, especially wrought magnesium alloys with enhanced mechanical properties have been developed, with the main aim of increasing ductility and formability. Alloying and processing studies allowed demonstrating the relationship between the processing and the microstructure development for many new magnesium alloys. Based on this experience, magnesium alloy compositions need adjustment to elements improving mechanical properties while being suitable for biomaterial applications. In this work, magnesium alloys from two Mg-Zn series with Ce (ZE) or Ca (ZX) as additional elements and a series of alloys with Ag and Ca (QX) as alloying elements are suggested. The microstructure development was studied after the extrusion of round bars with varied processing parameters and was related to the mechanical properties and the degradation behavior of the alloys. Grain refinement and texture weakening mechanisms could be improved based on the alloy composition for enhancing the mechanical properties. Degradation rates largely depended on the nature of second phase particles rather than on the grain size, but remained suitable for biological applications. Furthermore, all alloy compositions exhibited promising cytocompatibility.

Magnesium-Based Alloys Used in Orthopedic Surgery

“…The UTS in the case of cast Mg-6Ag was found to be equal to 215.9 ± 11.3 MPa, and the UCS was about 244 ± 9.2 MPa. The Ag presence determines a notable improvement in the material ductility, double when comparing it to that of pure magnesium [ 118 , 119 ].…”

Biodegradable Magnesium Biomaterials—Road to the Clinic

“…Ca has an impact on the development of texture during rolling or extrusion, causing weaker textures without a strong alignment of basal planes. Such textures are known to show lower anisotropic mechanical behavior and also higher ductility [137]. The in vitro and in vivo degradation behavior of binary Mg-xCa alloy (x = 0.5 or 5.0 wt.%) was determined by Makkar et al [116].…”

Carbon Nanotubes (CNTs)-Reinforced Magnesium-Based Matrix Composites: A Comprehensive Review

“…The advantageous properties could be attained only if the reinforcements are distributed homogeneously and not clustered in the matrix. According to the literature available [ 153 , 154 , 155 , 156 , 157 , 158 , 159 , 160 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 , 169 , 170 , 171 , 172 , 173 , 174 , 175 , 176 , 177 , 178 , 179 , 180 , 181 , 182 , 183 , 184 , 185 , 186 , 187 ], limited research has been performed on CNT-reinforced MMCs due to difficulties in fabricating and dispersion of CNTs in the matrix. Most studies investigated the fabrication methods such as the casting process and powder metallurgy for developing Mg-based alloy [ 188 , 189 , 190 , 191 , 192 , 193 , 194 , 195 , 196 , 197 , 198 , 199 , 200 , 201 ,…”