Deposition and Biological Evaluation of Ta Coating on Porous SiC Scaffold for Orthopedic Application

Porous Tantalum (Ta) is one of ideal orthopedic implant metal which can promote enough osteogenesis in the periphery of implant. Ta coatings were deposited on porous Silicon Carbon (SiC) substrate by chemical vapor deposition (CVD) method to provide a cancellous bone like 3D structure and suitable mechanical property. The biocompatibility of SiC substrate was also improved because of Ta coating. TaCl₅ powders was evaporated and reduced by H₂ working as reductant and the carrier gas, and then Ta coating was deposited on SiC scaffold. X-ray diffraction (XRD) results confirmed the deposition of Ta coating. Scanning electron microscopy (SEM) showed that Ta coating penetrated inside the porous structure of SiC substrate. It was found that the deposition temperature strongly affected the surface morphology and mechanical properties. The final samples showed good compatibility between Ta coating and SiC scaffold and suitable compressive strength. Ta-coated porous screws was designed and fabricated, and they were implanted to fix bone fracture. Comparing with Ti scaffolds Ta-coated porous screws demonstrated better osteogenesis property. This design of Ta coated SiC porous material was expected to be used as orthopedics device.