Surface integrity after pickling and anodization of Ti–6Al–4V titanium alloy

Abstract

The surface integrity of Ti-6Al-4V titanium alloy was studied at different stages of surface treatments, especially pickling and compact anodization, through surface characteristics potentially worsening fatigue resistance. No significant changes of the equiaxe microstructure were detected between sample core and surface, or after the pickling and anodization steps. Surface hydrogen and oxygen superficial contents were found to remain unchanged. Roughness characteristics (i.e. R a , R z but also local K t factor) similarly showed only slight modifications, although SPM and SEM revealed certain random local surface defaults, i.e. pits about 400 nm in depth. Finally internal stresses, evaluated using X-ray diffraction, highlighted a significant decrease of the compressive internal stresses, potentially detrimental for fatigue resistance.

Silver deposition on titanium surface by electrochemical anodizing process reduces bacterial adhesion of Streptococcus sanguinis and Lactobacillus salivarius

“…The samples were pretreated in acid solution (250 ml HNO 3 60% [Panreac, Castellar del Vallès, Spain], 17.5 g NH 4 HF 2 [Sigma‐Aldrich, St. Louis, MO, USA], and 250 ml ultrapure distilled water [Millipore Milli‐Q, Merck Millipore Corporation, Billerica, MA, USA]) for 10 s to remove surface contamination and the native surface titanium oxide layer (Vermesse et al. ).…”

A review of the surface modifications of titanium alloys for biomedical applications

“…The study focused on pickling and anodization. 38 An investigation of these processing techniques revealed no significant changes in the microstructure of the implant and surface oxygen and hydrogen superficial content were found to be unchanged. The roughness characteristics remained mostly unchanged.…”

Robust anodic colouring of titanium: Effect of electrolyte and colour durability

“…Yet, the robustness of the anodising treatment becomes vital to ensure brilliant and durable colours with reproducible hues, since in industrial processes parts that do not meet colour match criteria must be rejected [7,8]. Moreover, such process should, on one side, avoid alterations to surface finishing, and on the other side ensure to reach the lifetimes required by such applications, especially in presence of potential corrosion and wear issues -e.g., erosion by environmental dust, or prolonged contact with skin in consumer products [9][10][11][12][13]. This is even more important in biomedical applications, where coloured anodised titanium finds use in osteosynthesis devices and dental implants, with an added value of lower ion release and better tolerance by surrounding tissues compared with steel alloys [14,15].…”