This work evaluates the effects of laser surface modification on Mg-Zn-Gd-Nd alloy which is a potential biodegradable material for temporary bone implant applications. The laser surface melted (LSM) samples were investigated for microstructure, wettability, surface hardness and in vitro degradation. The microstructural study was carried out using scanning and transmission electron microscopes (SEM, TEM) and the phases present were analyzed using X-ray diffraction. The in vitro degradation behaviour was assessed in hank's balanced salt solution (HBSS) by immersion corrosion technique and the effect of LSM process parameters on the wettability was analyzed through contact angle measurements. The microstructural examination showed remarkable grain refinement as well as uniform redistribution of intermetallic phases throughout the matrix after LSM. These microstructural changes increased the hardness of LSM samples with an increase in energy density. The wetting behaviour of processed samples showed hydrophilic nature when processed at lower (12.5 and 17.5 J/mm2) and intermediate energy density (22.5 and 25 J/mm2), which can potentially improve cell-materials interaction. The corrosion rate of as cast Mg-Zn-Gd-Nd alloy decreased by ~83% due to LSM.

中文翻译：

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激光表面改性Mg-Zn-Gd-Nd合金的降解，润湿性和表面特性。

这项工作评估了激光表面改性对Mg-Zn-Gd-Nd合金的影响，Mg-Zn-Gd-Nd合金是用于临时骨植入应用的潜在生物可降解材料。研究了激光表面熔化（LSM）样品的微观结构，润湿性，表面硬度和体外降解。使用扫描和透射电子显微镜（SEM，TEM）进行微观结构研究，并使用X射线衍射分析存在的相。通过浸没腐蚀技术评估了汉克平衡盐溶液（HBSS）中的体外降解行为，并通过接触角测量分析了LSM工艺参数对润湿性的影响。显微组织检查表明，LSM后，晶粒细化以及整个基体中金属间相的均匀重新分布。这些微观结构的变化随着能量密度的增加而增加了LSM样品的硬度。当以较低的（12.5和17.5 J / mm2）和中等的能量密度（22.5和25 J / mm2）进行处理时，处理过的样品的润湿行为显示出亲水性，这可以潜在地改善细胞材料之间的相互作用。由于LSM，铸态Mg-Zn-Gd-Nd合金的腐蚀速率降低了约83％。