Surface Characterization on Alkali-Heat-Treatment on Titanium Alloy

Abstract

Coating of apatite in a biomimetic fluid is an alternative technique for metallic coating. Key element for effective biomimetic apatite coating depends on the surface material that can be enhanced by physical and chemical pre-treatment process. Two different preparations of Titanium alloy (Ti6Al4V) have been studied namely as received (as-Ti) and abraded (ab-Ti) with SiC paper. Both samples were then immersed in 5M NaOH and 5M KOH at temperature of 60 °C for 24 hours. A passive oxide layer covered on the surface of Ti6Al4V generally changed to form alkali (Na/K) titanate layer which is mechanically unstable. Therefore, alkali-treated Ti6Al4V were heat-treated at 700 °C for 1 hour to consolidate a mechanically stable structure of amorphous alkali titanate layer. Both samples before and after heat treatment were characterized using field emission scanning electron microscope, 3D surface metrology, contact angle goniometry and X-ray diffraction. The result indicates that as-Ti treated in 5 M KOH showed an existence of porous network structure.Keywords: titanium, active surface, alkali treatment, heat treatment Abstrak Penyalutan apatit dalam cecair biomimetik adalah teknik alternatif untuk salutan logam. Faktor utama dalam penyalutan logam dengan apatit secara biomimetik yang berkesan adalah bergantung kepada sifat permukaan bahan/logam. Sifat permukaan logam boleh ditambah baik melalui proses pra-rawatan secara fizikal dan kimia. Dua persediaan yang berbeza ke atas aloi Titanium (Ti6Al4V) telah dikaji iaitu seperti yang diterima (as-Ti) dan telah dilelas (ab-Ti) dengan kertas pasir silikon karbida (SiC). Kedua-dua sampel kemudiannya direndam ke dalam 5M NaOH dan 5M KOH pada suhu 60 °C selama 24 jam. Satu lapisan oksida pasif yang meliputi atas permukaan Ti6Al4V umumnya berubah untuk membentuk lapisan alkali (Na/K) titanat yang secara mekanikal adalah tidak stabil. Oleh itu, Ti6Al4V yang telah mengalami pra-rawatan alkali telah melalui proses pemanasan haba pada suhu 700 °C selama 1 jam untuk mengukuhkan kestabilan struktur mekanikal lapisan amorfus alkali titanat. Keduadua sampel sebelum dan selepas rawatan haba telah dianalisa menggunakan mikroskop elektron imbasan pancaran medan, metrologi permukaan 3D, sudut sentuhan goniometri dan pembelauan sinar-X. Hasil daripada kajian ini menunjukkan bahawa as-Ti yang dirawat dengan 5M KOH menunjukkan jelas kewujudan struktur jaringan berliang.

Influence of Calcium on the Structure and Hydrophilic of CaTiO3 Coating on Titanium Implants

“…The presence of sodium element in the sample is likely due to residual input solution. According to previous studies, the element Na does not affect the formation of CaTiO3 film coating on the Ti [17][18][19]. When treating titanium samples with NaOH solution will increase the biocompatibility of the material.…”