Microstructure, mechanical and bio-corrosion properties of Mg–Zn–Zr alloys with minor Ca addition

Abstract

In this research, effect of minor alloying element Ca on microstructure, mechanical and biocorrosion properties of as-cast Mg-3Zn-0.3Zr-xCa (x = 0, 0.3, 0.6, 0.9) alloys were investigated for biomedical application. The result showed that Ca played a dual role in mechanical properties and corrosion resistance. With minor Ca addition, the microstructure of the alloy is significantly refined and more uniform. The elongation, tensile strength and corrosion resistance of the studied alloys increases and then decreases with the increase of Ca content. With increasing the Ca content to 0.6 wt-%, the new strip phase of Ca 2 Mg 6 Zn 3 can be found, and gives the best strength and corrosion resistance. It was thought that the alteration of the second phase and the microstructure affect the mechanical and bio-corrosion properties.

Improved biodegradation resistance by grain refinement of novel antibacterial ZK30-Cu alloys produced via selective laser melting

“…1j. As demonstrated, MgZn 2 is the only intermetallic phase in Mg-Zn-Zr alloys [13] , whereas MgZn 2 and MgZnCu are two intermetallic phases in Mg-Zn-Zr-Cu alloys [14] . Therefore, the granular precipitates shown in Fig.…”

Bioactive fluorcanasite reinforced magnesium alloy‐based porous bio‐nanocomposite scaffolds with tunable mechanical properties

“…It has been reported that Ca, a grain refining agent, enhances the strength of grain boundary by solid solution strengthening, and also due to the segregation of Ca at grain boundaries resulting in texture weakening and grain refinement. 13,36,52,78 It was observed that S2 composition had higher compressive strength values as compared to that of S1 composition, which could be attributed to the formation of higher intensity Mg-Ca phase. 67 Additionally, incorporation of Zn into the magnesium matrix, results into possible formation of ordered structure in the alloy system.…”

“…12 Biodegradability in the scaffold material brings an added advantage that would avoid any revision surgery and associated complications. 13,14 Ceramics, metals, polymers and their composites have been traditionally used for fabricating bone scaffolds. Hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP), for example, are ceramic biomaterials which although possess bioactivity, are, not suitable for load-bearing applications due to their brittleness and low fracture toughness.…”

“…Hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP), for example, are ceramic biomaterials which although possess bioactivity, are, not suitable for load-bearing applications due to their brittleness and low fracture toughness. 11,13,15,16 Polymeric biomaterials are interesting because of their structural flexibility, which can render biodegradability and biocompatibility. [5][6][7][8]16,17 However, their insufficient mechanical properties restrict their use in orthopedic implants.…”

“…10,26,27 Unfortunately, the degradation rate of pure magnesium is very high in the physiological system due to the presence of chlorine ions, which results in compromising the structural integrity and in turn the mechanical performance of the scaffold, even before the necessary healing of hard tissue. 13,28 Besides, magnesium when immersed in the physiological solution, releases hydrogen gas, due to hydrolysis reaction, thereby hindering the growth of new bone cells. [29][30][31] These shortcomings of magnesium-based implants have been addressed in this study by incorporating selective alloying elements such as zinc (Zn), calcium (Ca), and strontium (Sr) within the magnesium matrix.…”