Mechanical properties and biocompatibility of Ta/Ti6Al4V composite porous structures printed using selective laser melting

The growing aging population and the increasing incidence of traumatic injuries have jointly intensified the clinical demand for bone repair materials and technologies. Tantalum (Ta) and titanium (Ti) alloys are widely used in clinical orthopedics—such as joint replacements, cranial implants, and spinal implants—due to their excellent biocompatibility and mechanical properties. Notably, tantalum exhibits outstanding biological performance, including superior osseointegration and antibacterial properties. In recent years, researchers have focused on fabricating tantalum coatings on titanium and its alloys to combine the advantages of both materials. Various coating techniques have been developed, including chemical vapor deposition, magnetron sputtering, vacuum plasma spraying, and selective laser melting (SLM). However, these methods still present limitations such as limited bonding strength, poor controllability of pore size and porosity, and mismatched elastic modulus. In this study, a Ta/Ti6Al4V composite porous structure with uniform pores was successfully prepared using SLM. The structure achieved metallurgical bonding between the two materials, with a bonding strength of up to 447.3 MPa and a compressive yield strength ranging from 66.1 to 87.4 MPa. Thanks to the fully porous design, the elastic modulus was significantly reduced (1.9–2.9 GPa), matching that of human bone tissue; in vitro experiments confirmed that its overall biocompatibility is comparable to that of pure Ta. Corrosion resistance tests demonstrated that the Ta/Ti6Al4V composite porous structures exhibit good chemical stability in simulated body fluid. The Ta/Ti6Al4V composite porous structures show promising potential as an orthopedic implant.