Developing a Novel Growth Method for Carbon-Infiltrated Carbon Nanotubes on Ti6Al4V

Abstract

Carbon-infiltrated carbon nanotubes (CICNT) are cylindrical rolls of pure carbon atoms with a honeycomb molecular structure. They have specific applications in medical implants due to their biofilm resistance properties. CICNT can be grown on a variety of material substrates such as silicon, stainless steel, and pure titanium. Different substrates require different CICNT growth processes. This study developed a growth method for CICNT on Ti6Al4V, a titanium alloy commonly used as a medical implant material due to its strong mechanical properties and excellent biocompatibility. However, due to the presence of vanadium in the alloy, it is difficult to use it as a substrate for CICNT growth. To solve this problem, this study used an indirect growth method, which placed a barrier layer of alumina (Al2O3) between the Ti6Al4V and an iron growth catalyst layer. A control group was also created without an alumina barrier layer. This study additionally investigated the differences between two deposition methods: electron-beam physical vapor deposition (PVD) and atomic layer deposition (ALD). After CICNT growth, the samples showed that the deposition of the barrier layer allowed the growth of CICNT on Ti6Al4V. Using a scanning electron microscope (SEM), the results also showed that at the levels of alumina studied, the deposition method did not make a difference to CICNT coverage of the Ti6Al4V. These results illustrate the fact that Ti6Al4V can be used as a substrate for CICNT if a barrier layer is used.