关键词: 增材制造, 钛合金, 骨科应用, 性能特点

Abstract:

Titanium alloys have long been regarded as the "gold standard" in the field of orthopedic implants due to their high specific strength, low elastic modulus, excellent biocompatibility and the stable oxide film formed by spontaneous passivation. However, traditional subtractive processing is difficult to simultaneously achieve topological optimization, gradient porosity and individualized anatomical matching. The emergence of additive manufacturing (AM) technology provides a systematic solution to the above bottleneck problems. Selective laser melting (SLM) and electron beam melting (EBM), as typical representatives of the powder bed melting (PBF) route, can precisely control the phase structure at the mesoscopic scale by melting the Ti-6Al-4V pre-alloyed powder layer by layer with a high-energy beam. The compressive elastic modulus is reduced from 110GPa in the traditional rolled state to be close to the cortical bone level (≈17GPa). This thesis reviews the latest research progress of titanium alloys in terms of elastic modulus regulation, porous structure design, enhanced biological activity and improved corrosion resistance. Then it discusses the differences and advantages of SLM and EBM technologies in forming accuracy, mechanical properties and biological behavior. At the same time, clinical cases of additively manufactured titanium alloys in typical orthopedic clinical applications such as hip replacement, intervertebral fusion devices and mandibular reconstruction are also analyzed. Additive manufacturing of titanium alloys is driving the transformation of orthopedic implants from the "standardization" paradigm to the "individual functionalization" paradigm through cross-scale mechanical adaptation, surface biological activation and precise structure reconstruction. In the future, key scientific issues such as non-destructive evaluation of printing defects, long-term biological response need to be further addressed.

Key words: additive manufacturing, titanium alloy, orthopedic application, performance characteristic