Search results for "Titanium"
showing 10 items of 878 documents
Frictional behaviour of oxygen diffusion hardened titanium in dry sliding against Co–28Cr–5W–4Fe–3Ni–1Si cobalt alloy
2004
Abstract The results of conformal pin-on-disc tribological tests of a hard layer of the solid solution of oxygen in α-titanium sliding against a Co–28Cr–5W–4Fe–3Ni–1Si cobalt alloy counterspecimen are presented. The α-Ti(O) layer was diffusely produced over 2–8 h of oxidising in the superficial zone of a technical quality titanium specimen. The friction and wear responses of the system were recorded and the wear mechanisms were studied. Investigations of the material structure and chemical constitution in micro-areas of the titanium specimen, cobalt alloy counterspecimen and wear debris formed in dry sliding were performed with a Philips XL20 microscope equipped with an EDAX analyser. Crush…
Fatigue Crack Growth in Titanium and Aluminium Alloys under Bending
2007
The paper contains results of investigations of the crack growth in plane specimens made of Ti-6Al-4V titanium alloy and AlCu4Mg1 aluminium alloy under cyclic bending. The tests were done on specimens with the stress concentrators being one-sided sharp notch. On the fractures there have been observed first of all transcrystalline cracks through the α phase grains for both materials.
Water Adsorption Properties of Titanium(IV) Oxide Embedded in Multiwalled Carbon Nanotubes (CNT)
2019
Titanium(IV) oxide was embedded into carbon nanotubes through sonication. The water adsorption properties of the carbon nanotubes, titanium(IV) oxide and the titanium(IV) oxide embedded carbon nanotubes have been studied using near infrared spectroscopy and second derivative techniques. Each sample was evacuated, then exposed to 40% and 60% relative humidity to adsorb water molecules and the evolving adsorption near infrared spectra were studied. Adsorption properties were further studied by gravimetric analysis. Near infrared spectroscopic and Scanning Electron Microscopic studies confirm that the titanium(IV) oxide has been embedded into the carbon nanotube samples. The water adsorption p…
Preparation and structural study of sodium germanium phosphate-sodium titanium phosphate solid solutions. I. Evolution of structure with composition
1993
Compounds NaM2IV(PO4)3 with M = Ge, Ti present the [NZP]-type structure, with a low thermal expansion. The space group at room temperature for the compound NaGe2(PO4)3 is R3, whereas for the compound NaTi2(PO4)3 is R3c. Evolution of the structure with composition in NaGe2(PO4)3 NaTi2(PO4)3 system is discussed. The space group and lattice parameters were determined for NaGe2−xTix(PO4)3 (0 < x < 2) solid solutions, prepared by ceramic method. Compositions rich in Ge(IV) (0 ≤ x ≤ 1) show the R3 space group, whereas for those rich in Ti(IV) (1.2 ≤ x ≤ 2) the space group is R3c. The variation of the lattice parameters with composition agreed with these results since it showed a change in its t…
Optimisation of TA6V alloy surface laser texturing using an experimental design approach
2008
International audience; Active surfaces of plastic injection moulds are nowadays textured using classical techniques (chemical etching or EDM). Replacement of these technologies by a laser technology introduces a big flexibility: absence of mechanical contact with the tool, decrease of the effluent's volume and a big machining precision, even in the case of the complex forms as injection moulds for example. This paper reports the experimental study of the surface laser texturing of TA6V alloy. The influence of the operating factors on the laser texturing process has been studied using two experimental approaches: Taguchi methodology and response surface methodology (RSM). Empirical models h…
Corrosion Behaviour of Ti6Al4V and TiMo10Zr4 Alloys in the Ringer’s Solution: Effect of pH and Plastic Strain
2015
The corrosion behaviour of titanium alloys is not well understood – especially the role of the microstructure and plastic strain. In this paper, the influence of the microstructure and plastic strain on the corrosion resistance of TiMo10Zr4 and Ti6Al4V alloys was studied in the Ringer’s solution at 37 °C. Measurements were performed for different pH values and in aerated and de-aerated solutions using potentiodynamic polarization techniques. Results obtained on the two alloys were compared. It was shown that in the absence of plastic strain TiMo10Zr4 shows better corrosion resistance than Ti6Al4V (especially for pH = 8). By contrast, the current density in the passive range measured after 8…
Corrosion resistance of the vacuum arc deposited Ti, TiN and TiO2 coatings on large area glass substrates
2000
An industrial installation for vacuum arc deposition is presented. Its potential in the field of decorative coatings for large area glass sheets is demonstrated. In particular it is possible to deposit patterned coatings through a polymeric textile mask. The ability to deposit uniform multilayer coatings having interference colours onto large silicate glass sheets is shown. Titanium, titanium nitride and titanium dioxide coatings on silicate glass have been characterized in terms of composition and corrosion resistance. Depth profiling was achieved with the aid of Auger electron spectroscopy. The corrosion resistance of TiN coatings is higher than that of TiO 2 . The corrosion resistance of…
SEM and XPS studies of titanium dioxide thin films grown by MOCVD
1998
Abstract The metal organic chemical vapour deposition (MOCVD) method was used to prepare titanium dioxide thin films. Thin films of TiO2, about 100 nm thick, were deposited on (100)Si and (1102)Al2O3 sapphire substrates using titanium isopropoxide (Ti(OC3H7)4) as metal organic precursor. The morphology of the films and the presence of impurities on the thin films surfaces were studied using respectively, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The influence of the growth parameters such as the deposition temperature, the carrier gas (nitrogen) flow rate and the presence of an additional oxygen flow on the characteristics of the titanium dioxide films h…
The Effect of Building Direction on Microstructure and Microhardness during Selective Laser Melting of Ti6Al4V Titanium Alloy
2021
AbstractDuring the last few years, additive manufacturing has been more and more extensively used in several industries, especially in the aerospace and medical device fields, to produce Ti6Al4V titanium alloy parts. During the Selective Laser Melting (SLM) process, the heterogeneity of finished product is strictly connected to the scan strategies and the building direction. An optimal managing of the latter parameters allows to better control and defines the final mechanical and metallurgical properties of parts. Acting on the building direction it is also possible to optimize the critical support structure. In particular, more support structures are needed for the sample at 0°, while very…
Enhanced surface area in thermally stable pure mesoporous TiO2
2000
Abstract We describe here for the first time the surfactant-assisted synthesis of thermally stable mesoporous pure TiO 2 having a high surface area. Our synthetic approach to the chemistry of this system is based on the equilibrium between the hydrolysis and condensation reactions of the inorganic species and the organic–inorganic self-assembling processes. The use of titanatrane complexes helps to retard the hydrolysis and condensation reactions, thus allowing us to overcome the difficulties in preparing titanium dioxide mesoporous materials starting from highly reactive Ti-alkoxides. The mesoporous material has been characterized by TEM, XRD and N 2 adsorption–desorption isotherms and dis…