Papers by Keyword: IBAD

Abstract: Titanium dioxide has been used for environmental applications. However, pure TiO₂ has low photocatalytic efficiency outdoors because of its large energy band gap. Higher nitrogen-doping level would have lower band-gap energy and it would make it possible to improve the utilization ratio of solar energy. Heavily nitrogen-doped TiO2 could be obtained by using ion beam assisted deposition (IBAD) technique. Acceleration voltage is a very important parameter of IBAD technique and will affect the processes of depositing thin film. Under the given experiment condition, acceleration voltage had little effect on the structure and absorbance spectra of the obtained nitrogen-doped titanium oxide thin films, but had great effect on the deposition rate, composition and surface morphology of the thin films. When the accelerate voltage was 250V, the deposition rate was the highest (about 9.0 nm/min), the resulting TiO2-xNx films contained nitrogen levels up to x =0.45, the structures were mostly crystalline anatase and the amount of shift was observed about 500 nm. The optimum acceleration voltage is about 250V under the given condition.

Abstract: Ti–Si–C coatings were formed at room temperature on AISI 316L steel substrates by dual beam ion assisted deposition technique from single compound Ti3SiC2 target. Scanning and transmission electron microcopy method were used to examine as-deposited coatings. Their morphology was smooth and dense and their thickness were in the range from 100 nm to 1μm. Raman spectra of coated substrates were collected up with five peaks at the same positions as for Ti3SiC2 compound target. TEM and HRTEM examinations, accompanied by SAED analyses revealed that deposited films were amorphous. Nanoindentation tests were provided on coated and uncoated substrates and hardness HIT and reduced elastic modulus EIT were calculated using the Oliver & Pharr method.

Abstract: In this paper, we present results of a study of TiN films which are deposited by Physical Vapor Deposition and Ion Beam Assisted Deposition. In the present investigation the subsequent ion implantation was provided with N2+ ions. The ion implantation was applied to enhance the mechanical properties of the surface. The film deposition process exerts a number of effects such as crystallographic orientation, morphology, topography, densification of the films. The evolution of the microstructure from porous and columnar grains to densely packed grains is accompanied by changes in mechanical and physical properties. A variety of analytic techniques were used for characterization, such as scratch test, calo test, SEM, AFM, XRD and EDAX. The experimental results indicated that the mechanical hardness is elevated by penetration of nitrogen, whereas the Young’s modulus is significantly elevated. Thin hard coatings deposited by physical vapour deposition (PVD), e.g. titanium nitride (TiN) are frequently used to improve tribological performance in many engineering applications. Ion bombardment during vapour deposition of thin films, colled ion beam assisted deposition (IBAD), exerts a number of effects such as densification, changes in grain size, crystallographic orientation, morphology and topography of the films. This paper describes the successful use of the nanoindentation technique for determination of hardness and elastic modulus. In the nanoindentation technique, hardness and Young’s modulus can be determined by the Oliver and Pharr method. Therefore, in recent years, a number of measurements have been made in which nanoindentation and AFM have been combined.

Abstract: A part of the titanium dental implant surface, which will meet connective tissue after being inserted in mandibular bone, was coated with calcium phosphate by ion beam assisted deposition (IBAD). Twenty-four implants of coated and uncoated group were randomly placed in mandibles after 3 months of premolars extraction in beagle dogs. All the implants were firmly anchored in the bone and had no clinical signs of peri-implant inflammation after 3-month insertion. The probing depth in calcium phosphate coated group is 1.9±0.2 mm, less than in control group (2.1±0.2 mm) (p<0.05). Most of the probing sites tended to bleed upon probing in two groups. It might indicate that the calcium phosphate coating has the potential to promote soft tissue integration.