Effect of Ball Milling on the Structural and Bioactivity Properties of Commercially Pure Titanium

Abstract

Commercially pure titanium (Cp-Ti) is widely used as an orthopaedic implant due to its excellent corrosion resistance, low density and less stiffness. A porous metallic implant will lead to better osseointegration than bulk metallic implants. In this study, Cp-Ti powder with 99 % purity was ball milled for various time intervals in a planetary ball mill using toluene as a wetting medium to avoid excess heat. The as ball milled powders were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and dynamic light scattering (DLS) techniques. The results show that under the condition of wet milling, the particle size of the Cp-Ti milled powders is decreased with the increase in ball milling time. The XRD was performed on the samples of milled Cp-Ti powders, and a peak broadening was seen in the sample of 10 h, indicating the refinement of crystallite size. The reduction in particle size was confirmed by performing DLS of the as-milled powders. The powders were compacted and sintered for in-vitro bioactivity studies immersed in simulated body fluid (SBF) for 14 days to observe the apatite formation. After immersion in SBF, the compacts were observed in FESEM to confirm apatite formation. The enhanced apatite growth, as compared to bulk Cp-Ti, makes them a suitable implant material with better osseointegration