Search results for "Al alloy"

Small-diameter titanium Grade IV and titanium-zirconium implants in edentulous mandibles: three-year results from a double-blind, randomized controll…

2015

OBJECTIVE: The aim of this study was to compare crestal bone-level changes, soft tissue parameters and implant success and survival between small-diameter implants made of titanium/zirconium (TiZr) alloy or of Grade IV titanium (Ti) in edentulous mandibles restored with removable overdentures. MATERIALS AND METHODS: This was a randomized, controlled, double-blind, split-mouth multicenter clinical trial. Patients with edentulous mandibles received two Straumann bone-level implants (diameter 3.3 mm), one of Ti Grade IV (control) and one of TiZr (test), in the interforaminal region. Implants were loaded after 6-8 weeks and removable Locator-retained overdentures were placed within 2 weeks of l…

Tuning of Solid-sate Properties of Al Mixed Oxides Grown on Sputter-deposited Al Alloys.

2012

Reshaping End-of-Life components by sheet hydroforming: An experimental and numerical analysis

2022

In this study, a numerical/experimental analysis is proposed to investigate the possibility of reshaping sheet metal-based End-of-Life (EoL) components using sheet Hydroforming (SHF). Returned EoL components are challenging to be reformed, they are usually characterised by high heterogeneity as there are localised thinning areas (caused by the original forming processes), and the overall formability is reduced with respect to the original flat sheet material. The reshaping route was replicated: a deep drawing process was adopted to impart a square feature; subsequently, SHF was performed. The capability of remove the deep drawn feature was analysed with varying Blank-holder force, oil press…

[The effect of instrumentation on original apical foramen shape using steel vs niti rotatory: computerized analysis]

2002

BACKGROUND. A fundamental requirement to obtain a correct endodontic preparation depends on the respect, during cleaning and shaping, of the original morphology of the apical foramen, (AF), so that the filling material will form a complete seal. METHODS. In our previous studies, in order to verify if this presumption was respected using rotary NiTi instruments with cutting tip, we instrumented extracted teeth characterised by a different degree of root curvatures. Using a standardized system to replace the sample, the original shape of the apical foramen of each tooth was recorded using a computerised technique and then compared to the shape after instrumentation. The data showed difference…

Structural and hydrogenation study on the ball milled TiH2–Mg–Ni

2015

International audience; With the aim of further understanding for TieNieMg alloys and their hydrogenation behavior, powders of TiH2, Mg and Ni with the molar ratio of 3:1:2 have been mechanically milled for 10 h, 20 h, 30 h, 40 h according to the stoichiometry (TiH2)1.5Mg0.5Ni. Microstructures of the milled sample were analyzed and their hydrogenation properties as negative electrodes for Ni-MH batteries were studied. Phase change with milling time revealed the fast formation of the Ti-Mg-H FCC phase. The alloying priority among Ti, Mg and Ni was demonstrated by comparing phase compositions in different milling time. Hydrogen capacities evaluated by both solidegas reaction and electrochemic…

An Overview on the Performance of 1,2,3-Triazole Derivatives as Corrosion Inhibitors for Metal Surfaces

2021

This review accounts for the most recent and significant research results from the literature on the design and synthesis of 1,2,3-triazole compounds and their usefulness as molecular well-defined corrosion inhibitors for steels, copper, iron, aluminum, and their alloys in several aggressive media. Of particular interest are the 1,4-disubstituted 1,2,3-triazole derivatives prepared in a regioselective manner under copper-catalyzed azide-alkyne cycloaddition (CuAAC) click reactions. They are easily and straightforwardly prepared compounds, non-toxic, environmentally friendly, and stable products to the hydrolysis under acidic conditions. Moreover, they have shown a good efficiency as corrosi…

ODS tērauda izejmateriālu lokālās struktūras analīze izmantojot Ti un Y K-malas rentgenabsorbcijas spektroskopiju

2017

Šajā darbā tika izmantota rentgenstaru absorbcijas spektru analīze oksīdu stiprinātam tēraudam (ODS), kas ir perspektīvs materiāls dažādās jomās, piemēram, saules elektrostacijās, reaktīvos dzinējos, ķīmiskos reaktoros un kodolreaktoros, jo materiālam piemīt tādas īpašības kā laba siltumvadītspēja un zema termiskās izplešanās apvienojumā ar augstu temperatūras izturību, korozijas un radiācijas pretestību. Darbā tiek iegūta informācija par ar dažādām metodēm izgatavotu ODS tēraudu lokālās atomārās struktūras izmaiņu ap itrija (Y) un titāna (Ti) atomiem, analizējot Y un Ti absorbcijas K-malu.

Incorporation mechanism of colloidal TiO2 nanoparticles and their effect on properties of coatings grown on 7075 Al alloy from silicate-based solutio…

2021

Plasma electrolytic oxidation (PEO) was applied using a pulsed unipolar waveform to produce Al2O3-TiO2 composite coatings from sol electrolytic solutions containing colloidal TiO2 nanoparticles. The sol solutions were produced by dissolving 1, 3, and 5 g/L of potassium titanyl oxalate (PTO) in a silicate solution. Scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, and Raman spectroscopy were applied to characterizing the coatings. Corrosion behavior of the coatings was investigated using polarization and impedance techniques. The results indicated that TiO2 enters the coating through all types of micro-discharging and is doped into the alumina phase. The higher…

Effect of Molybdate on Corrosion Performance of Oxide Coating Produced on 7075 Al Alloy Using PEO

2022

In this research, plasma electrolytic oxidation (PEO) coatings were prepared on 7075 Al alloy in a silicate-based solution with Na2MoO4 additive using a unipolar waveform at constant current density. The coatings displayed micro-pores, micro-cracks, pancake-like and crater-like features, and also solidified molten oxide particles on the surface. The coatings were majorly composed of Al2O3 (γ, δ, and α), SiO2 (amorphous), and MoO3 phases, which confirms the incorporation of molybdenum in the case of additive-containing coatings. Molybdenum species were transported through cracks, channels, and micropores, as the ready access pathways into the coating and partly sealed the c…

Synergistic effect of W incorporation and pulsed current mode on wear and tribocorrosion resistance of coatings grown by plasma electrolytic oxidatio…

2019

Ceramic coatings were grown by plasma electrolytic oxidation on 7075 Al alloy using unipolar and bipolar pulsed current waveforms with 20 and 40% cathodic duty cycles, from a silicate-based bath without and with the addition of Na2WO4. Pancake-like morphology was dominant on the coatings grown by unipolar waveform, while the bipolar waveforms promoted volcano-like morphology, increased the roughness of the coating surface and the formation of more compact layers. The coatings produced using the bipolar waveforms provided higher resistances toward both tribocorrosion and dry sliding conditions, while further improvement was achieved by the presence of tungsten. The coatings produced in tungs…