School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing, China.
Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing, China.
J Biomed Mater Res B Appl Biomater. 2020 Apr;108(3):698-708. doi: 10.1002/jbm.b.34424. Epub 2019 Jun 4.
The microstructures, corrosion behavior, and mechanical degradation of the as-extruded Mg-6.0Gd-0.5Zn-0.4Zr (wt %, GZ60K) and Mg-6.0Gd-1.0Zn-0.4Zr (wt %, GZ61K) alloys were investigated. In both alloys, stacking faults and precipitates are formed in the recrystallized microstructures. The corrosion rate of GZ61K calculated by the hydrogen evolution in simulated body fluid is 0.34 ± 0.13 mm/year, which is lower than that of GZ60K (0.45 ± 0.09 mm/year); and the current density of GZ61K (5.23 ± 1.41 μA cm ) is much lower than that of GZ60K (11.95 ± 3.37 μA cm ). The corrosion results indicate GZ61K is more resistant to corrosion than GZ60K, but GZ60K presents more uniform corrosion mode as compared to GZ61K. After immersion in simulated body fluid for 7, 14, and 21 days, a slight decrease in the strength of both alloys is observed. The yield strength half-life is assessed for mechanical degradation and determined to be 125 and 85 days for GZ60K and GZ61K, respectively. The as-extruded GZ60K alloy with more uniform corrosion and longer mechanical integrity shows promising potential for orthopedic application.
研究了挤压态 Mg-6.0Gd-0.5Zn-0.4Zr（wt%，GZ60K）和 Mg-6.0Gd-1.0Zn-0.4Zr（wt%，GZ61K）合金的微观组织、腐蚀行为和力学降解。在这两种合金中，再结晶组织中形成了层错和析出物。在模拟体液中通过析氢计算出 GZ61K 的腐蚀速率为 0.34±0.13mm/年，低于 GZ60K（0.45±0.09mm/年）；并且 GZ61K 的电流密度（5.23±1.41μA·cm ）远低于 GZ60K（11.95±3.37μA·cm ）。腐蚀结果表明，GZ61K 比 GZ60K 更耐腐蚀，但与 GZ61K 相比，GZ60K 呈现更均匀的腐蚀模式。在模拟体液中浸泡 7、14 和 21 天后，两种合金的强度均略有下降。对机械降解进行了强度半衰期评估，确定 GZ60K 和 GZ61K 的半衰期分别为 125 和 85 天。挤压态 GZ60K 合金具有更均匀的腐蚀和更长的机械完整性，在骨科应用方面具有广阔的应用前景。
