Thin films produced on 5052 aluminum alloy by plasma electrolytic oxydation with red mud-containing electrolytes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Corrosion resistance of 2024 aluminum alloy coated with plasma deposited a-C:H:Si:O films

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ultrasonic sensor signals and optimum path forest classifier for the microstructural characterization of thermally-aged inconel 625 alloy

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Biofilm formation on the surface of Ti–7.5Mo alloy after surface treatment

Purpose: In the present work, a susceptibility and efficacy of the Ti–7.5Mo alloy and Ti alloy to bacterial biofilm formation after surface treatment was evaluated. Methods and materials: The alloy Ti–7.5Mo was obtained in arc furnace under an argon atmosphere. Ingots were then homogenized under vacuum at 1100 °C for 86.4 ks to eliminate chemical segregation and after cold worked discs were cutting. Samples were immersed in NaOH aqueous solution (5 M) and treated at 450 °C. Biofilms were grown in Ti–7.5Mo discs immersed in sterile brain heart infusion broth (BHI)containing 5% sucrose, inoculated with microbial suspension (106 cells/ml) and incubated for 5 days. Next, the discs were placed in tubes with sterile physiological solution 0.9% sodium chloride (NaCl) and sonicated for to disperse the biofilms. Tenfold serial dilutions were carried and aliquots seeded in selective agar, which were then incubated for 48 h. Then, the numbers CFU/ml (log 10) were counted and analyzed statistically. Scanning electron microscopy (SEM) on discs with biofilms groups was performed, atomic force microscope (AFM) and contact angle. Results: The results show that there is a 5% difference in bacterial adhesion between pure titanium and Ti–7.5Mo alloy. Conclusion: It was concluded that the greater the roughness, the greater the hydrophilic effect.

Improved response of the Ti30Ta experimental alloy after surface treatment for dental applications

The purpose of the study was to evaluate the influence of the biomimetic surface treatment in osseointegration of experimental alloy Ti30Ta for dentistry applications. Methods and materials: Experimental alloy with Ta concentration of 30 wt% was produced from sheets of commercially pure titanium (99.9%) and tantalum (99.9%). Ingots were melted in an arc furnace under an argon atmosphere and re-melted ten times at least. They were homogenized under vacuum at 1100 °C for 86.4 ks to eliminate chemical segregation and cold-worked by swaging. Implants with 2.5 mm diameter and 2.0 mm of height were machined (Fig. 1a), treated and inserted in animals for in vivo study. The implants were submitted surface treatment according methodology development for our group. Analyzes were performed by Scanning Electron microscopy (SEM), Atomic Force Microscopy (AFM). Osteoblast morphology on Ti-30Ta alloys was examined after 4 and 7 days of incubation with MSCs using SEM imaging.