The mechanical behavior of nickel-titanium shape memory alloys (NiTi SMA) presents unique features that benefit the bone fracture healing process: matching elastic modulus ranges, the ability to recover large deformations, and mechanical dissipation capacity. In this sense, this work proposes a new manufacturing process for NiTi SMA bone implants, particularly bone plates: additive manufacturing assisted investment casting (IC). This process delivers near-net NiTi SMA parts with either simple or complex shapes, also allowing a high degree of customization. Four identical NiTi SMA bone plates were manufactured through IC and characterized. Four-point bending tests were performed on the bone plate prototypes to verify their mechanical and fatigue behaviors. The NiTi bone plates have an elastic modulus of the order of 49 GPa at 37 C and recovered all deformations upon unloading when submitted to four-point bending deflections up to 4 mm. The fatigue life was between 10³ and >10⁵, depending on the deflection amplitude. Our next work with this technology will address aspects of cytotoxicity and implantation of the part in animals.

镍钛形状记忆合金（NiTi SMA）的机械性能具有有益于骨折愈合过程的独特功能：匹配的弹性模量范围，恢复大变形的能力以及机械耗散能力。从这个意义上讲，这项工作提出了一种用于NiTi SMA骨植入物（尤其是骨板）的新制造工艺：增材制造辅助熔模铸造（IC）。此过程可提供形状简单或复杂的近净NiTi SMA零件，还可以实现高度定制。通过IC制造并表征了四个相同的NiTi SMA骨板。对骨板原型进行了四点弯曲测试，以验证其机械性能和疲劳行为。NiTi骨板在37°C时的弹性模量约为49 GPa，当承受最大4 mm的四点弯曲挠度时，在卸荷时恢复了所有变形。疲劳寿命在10之间³和> 10 ⁵，取决于偏转幅度。我们使用该技术的下一个工作将解决细胞毒性和将零件植入动物的问题。