Recently, there has been an extension of three‐dimensional (3D) printing technology of metal materials in the medical field. Additive technology has made it possible to manufacture customized implants. However, 3D printing products often require surface treatment. The possible treatments include acid etching. This study investigated the effect of surface etching on the corrosion resistance of Ti–6Al–4V alloy concerning biological applications. The samples were etched in a mixture of hydrofluoric acid and nitric acid. The corrosion behaviour was described by measuring the time dependence of polarization resistance in a saline solution and surface analysis. The results showed that etching creates a fluoride‐rich layer on the surface, which negatively affects the corrosion behaviour of the material for up to 24 hr. Cytocompatibility tests showed that the resulting layer does not affect the biocompatibility of the material.

中文翻译：

---

表面蚀刻对三维印刷Ti-6Al-4V合金腐蚀行为的影响

最近，在医学领域对金属材料的三维（3D）打印技术进行了扩展。添加剂技术使制造定制植入物成为可能。但是，3D打印产品通常需要表面处理。可能的处理方法包括酸蚀。这项研究调查了表面蚀刻对Ti-6Al-4V合金在生物应用方面的耐蚀性的影响。在氢氟酸和硝酸的混合物中蚀刻样品。通过测量盐溶液中极化电阻的时间依赖性和表面分析来描述腐蚀行为。结果表明，蚀刻会在表面上形成一层富含​​氟化物的层，这会对材料的腐蚀行为产生长达24小时的负面影响。