Producing High Wettable Surface on Pure Titanium Sheets by Shot Peening for Bone Implant Applications

Pure titanium (Ti) sheets were subjected to shot peening to achieve grain refinement at the surface. Microstructural studies revealed significant grain refinement at the surface of the Ti sheet after shot peening. The affected thickness of the grain refined region was measured as 150 µm at the cross-section. Due to the fine grain structure, higher hardness was measured for the processed surface. X-ray diffraction studies of the processed sample showed peak broadening for processed Ti due to shot peening. Wettability studies conducted by contact angle measurements clearly showed increased hydrophilicity for the processed Ti as reflected in the lower contact angles. Increased surface energy was calculated for the shot-peened Ti, which can be attributed to the role of the increased fraction of grain boundaries due to microstructure modification. The results demonstrate the potential of the shot peening process to improve the surface wettability and further directly enhance the bioactivity of the Ti implant.