Biomedical applications of the powder-based 3D printed titanium alloys: A review

3D printing technology is a new type of precision forming technology and the core technology of the third industrial revolution. The powder-based 3D printing technology of titanium and its alloys have received great attention in biomedical applications since its advantages of custom manufacturing, costsaving, time-saving, and resource-saving potential. In particular, the personalized customization of 3D printing can meet specific needs and achieve precise control of micro-organization and structural design. The purpose of this review is to present the most advanced multi-material 3D printing methods for titanium-based biomaterials. We first reviewed the bone tissue engineering, the application of titanium alloy as bone substitutes and the development of manufacturing technology, which emphasized the advantages of 3D printing technology over traditional manufacturing methods. What is more, the optimization design of the hierarchical structure was analyzed to achieve the best mechanical properties, and the biocompatibility and osseointegration ability of the porous titanium alloy after implantation in living bodies was analyzed. Finally, we emphasized the development of digital tools such as artificial intelligence, which provides new ideas for the rational selection of processing parameters. The 3D printing titanium-based alloys will meet the huge market demand in the biomedical field, but there are still many challenges, such as the trade-off between high strength and low modulus, optimization of process parameters and structural design. We believe that the combination of mechanical models, machine learning, and metallurgical knowledge may shape the future of metal printing. ?? 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.