The effect of heat-treatments on the microstructure and strength of cervical cage with bone-like irregular porous structure additively manufactured by selective laser melting

다국어 초록 (Multilingual Abstract)

With the introduction of additive manufacturing by selective laser melting, complex shape such as porous structure became to manufacturability. However, it is reported that the additively manufactured Ti-6Al-4V implant has low ductility due to the needle-shaped alpha prime martensitic microstructure, and can be increased through heat treatment.
Therefore, this study was to confirm the effect of heat treatment through changes in the microstructure and mechanical strength of porous Ti-6Al-4V implants additively manufactured. In the case of the specimen, an irregular porous structure like bone was applied to the cervical cage. And heat treatment was performed at 650°C for 2 hours and at 800°C for 2 hours. The specimens were measured the change in microstructure with EBSD, and mechanical strength was evaluated according to ASTM F2077 standard. As a result, it was confirmed that alpha prime phase decomposition occurred and precipitation of the beta phase in the specimens heat treated at 650°C and 800°C for 2 hours. And it was confirmed that the particle size of the beta phase grew at 800°C compared to 650°C. In addition, it showed improved ductility compared to the decreased strength at 800°C. We confirmed that heat treatment at 800 °C for 2 hours on the additively manufactured porous cervical cage is a suitable condition to improve the microstructure characteristics and ductility.