Serial innovation and applications of additively manufactured Ta-based medical devices

Xingchen Yan

Institute of New Materials, Guangdong Academy of Sciences, Guangzhou, PR China
363 Changxing Road, Tianhe District, Guangzhou, Guangdong Province, 510650, P.R.China

Additive manufacturing (AM) of tantalum (Ta) and its alloys has shown significant potential in medical applications, owing to their exceptional mechanical and biological properties. However, defect formation during AM process remains a critical challenge, significantly impacting the performance of implants. This work systematically investigates the selective laser malting (SLM) of Ta-based medical devices, focusing on processing parameter optimization, microstructure-property relationships, and biological performance. Single-track and bulk samples were fabricated under optimized processing conditions, and a powder-resolved computational fluid dynamics (CFD) model of pure Ta was developed to analyze heat transfer and fluid flow characteristics in the molten pool. The results reveal that laser energy density plays a critical role in determining temperature and velocity fields, which influence defect types and quantities. Higher energy density improves molten pool spreading and reduces keyholes but increases gas pores due to intense Marangoni convection. Innovations in powder preparation, including the development of a radio-frequency plasma spheroidization (RFPS) method, have enabled the production of high-quality spherical Ta powders for medical. Additionally, the establishment of a Ta-adapted "laser-powder-molten pool" model and the use of response surface methodology have optimized AM processing, achieving mechanical properties comparable to as-forged Ta. A database of Chinese bone structures was established, leading to the development of implants more suited for humans. These implants have passed comprehensive biosafety validations and clinical trials, with multiple registration certificates for AM-fabricated medical devices currently under application. This study highlights the advancements in AM of Ta, offering scientific and theoretical support for optimizing processing parameters, reducing defects, and advancing the applications of Ta-based implants in medical fields.