Scholarlink

<p>Mg–Zn–Sn–Ca alloys are some of the most promising biodegradable materials for load-bearing biomedical applications This work investigates the influence of Zn and Sn additions on the microstructure, mechanical properties, and corrosion behaviour of Mg–Zn–(Sn)–1Ca alloys intended for orthopaedic applications. Increasing the Zn and Sn content in Mg–1Ca alloys significantly enhanced hardness by promoting secondary phase formation and increasing dislocation density. Among the investigated compositions, the ZTX421 alloy (Mg–1Ca–4Zn–2Sn) exhibited the most pronounced grain refinement (39.72 ± 3.2 µm), highest hardness (127.85 ± 4.3 HV), and greatest dislocation density (14.5 × 10<sup>14</sup> m<sup>−2</sup>), outperforming ZX31 (48.31 ± 3.8 µm, 84 ± 13.8 HV, 10.11 × 10<sup>14</sup> m<sup>−2</sup>) and ZTX311 (53.88 ± 2.6 µm, 98.1 ± 8.3 HV, 11.7 × 10<sup>14</sup> m<sup>−2</sup>). ZTX311 (Mg–3Zn–1Sn–1Ca) achieved the highest ultimate tensile strength (179 MPa) and yield strength (98 MPa), along with a uniform secondary phase distribution along grain boundaries. The variation in alloy composition significantly influenced ductility, with ZX31 and ZTX421, exhibiting higher strain-to-fracture (~17%) compared to ZTX311 (~13%). The degradation performance was found to be closely linked to the microstructure and the presence of secondary phases. Electrochemical testing revealed that ZTX311 possessed the best corrosion resistance, with the lowest initial corrosion current density (3.244 ± 0.13 μA·cm<sup>−2</sup>) and minimum initial corrosion rate (~0.141 mm·y<sup>−1</sup>) obtained from Tafel extrapolation. This superior performance is attributed to the formation of a stable Mg(OH)<sub>2</sub> protective layer, combined with a favourable microstructure that reduced micro-galvanic effects and suppressed further degradation during immersion. In contrast, ZTX421, despite its higher Zn and Sn content, displayed inferior corrosion resistance due to the presence of larger dendritic cathodic intermetallic phases. Overall, the balanced mechanical strength and corrosion resistance of ZTX311 highlight its potential as a promising candidate for future <i>in vivo</i> evaluation as an orthopaedic implant material.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Comparative Evaluation of Biodegradable Mg–1Ca–Zn–(Sn) Alloys: Effects on Microstructure, Mechanical Properties, and Corrosion Behaviour for Orthopaedic Implants

  • 期刊论文

  • 发表日期：

    2025年10月8日

查看全文
  • Pradipta Kumar Rout,
  • Sourav Ganguly,
  • Dinesh Rathore,
  • Sudesna Roy

摘要

Mg–Zn–Sn–Ca alloys are some of the most promising biodegradable materials for load-bearing biomedical applications This work investigates the influence of Zn and Sn additions on the microstructure, mechanical properties, and corrosion behaviour of Mg–Zn–(Sn)–1Ca alloys intended for orthopaedic applications. Increasing the Zn and Sn content in Mg–1Ca alloys significantly enhanced hardness by promoting secondary phase formation and increasing dislocation density. Among the investigated compositions, the ZTX421 alloy (Mg–1Ca–4Zn–2Sn) exhibited the most pronounced grain refinement (39.72 ± 3.2 µm), highest hardness (127.85 ± 4.3 HV), and greatest dislocation density (14.5 × 1014 m−2), outperforming ZX31 (48.31 ± 3.8 µm, 84 ± 13.8 HV, 10.11 × 1014 m−2) and ZTX311 (53.88 ± 2.6 µm, 98.1 ± 8.3 HV, 11.7 × 1014 m−2). ZTX311 (Mg–3Zn–1Sn–1Ca) achieved the highest ultimate tensile strength (179 MPa) and yield strength (98 MPa), along with a uniform secondary phase distribution along grain boundaries. The variation in alloy composition significantly influenced ductility, with ZX31 and ZTX421, exhibiting higher strain-to-fracture (~17%) compared to ZTX311 (~13%). The degradation performance was found to be closely linked to the microstructure and the presence of secondary phases. Electrochemical testing revealed that ZTX311 possessed the best corrosion resistance, with the lowest initial corrosion current density (3.244 ± 0.13 μA·cm−2) and minimum initial corrosion rate (~0.141 mm·y−1) obtained from Tafel extrapolation. This superior performance is attributed to the formation of a stable Mg(OH)2 protective layer, combined with a favourable microstructure that reduced micro-galvanic effects and suppressed further degradation during immersion. In contrast, ZTX421, despite its higher Zn and Sn content, displayed inferior corrosion resistance due to the presence of larger dendritic cathodic intermetallic phases. Overall, the balanced mechanical strength and corrosion resistance of ZTX311 highlight its potential as a promising candidate for future in vivo evaluation as an orthopaedic implant material.