scholarly journals Oxidation kinetics of commercially pure titanium

2007 ◽  
Vol 12 (3) ◽  
pp. 525-531 ◽  
Author(s):  
E. Gemelli ◽  
N.H.A. Camargo
Keyword(s):  
Oxidation Kinetics ◽  
Room Temperature ◽  
Thermal Analyses ◽  
Pure Titanium ◽  
Thermal Characterization ◽  
Commercially Pure Titanium ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Commercially Pure

The aim of this work was to perform thermal characterization of commercially pure titanium in dry air to determine its oxidation kinetics and the structure of the oxide. The oxidation kinetics were determined thermogravimetrically under isothermal conditions in the temperature range 300 to 750 ºC for 48 hours and the structure of the oxides was determined by differential thermal analyses and X-ray diffraction in the temperature range room temperature - 1000ºC. The oxidation rate of titanium increased with increase in temperature. It was high in the initial stages of oxidation and then decreased rapidly with time, especially up to 600 ºC. The kinetic laws varied between inverse logarithmic at the lower temperatures (300 and 400 ºC) and parabolic at the higher temperatures (650, 700 and 750 ºC). Evidences from X-ray diffraction and differential thermal analyses data revealed that the passive oxide film formed at room temperature crystallized into anatase at about 276 ºC. The crystallized oxide formed in the range 276 - 457 ºC consisted of anatase, in the range 457 - 718 ºC consisted of anatase and rutile sublayers, and at temperatures beyond 718 ºC consisted of a layer of pure rutile. Scanning electron microscopy observations reveled that the oxidized surfaces were crack-free and the surface roughness increased steadily with oxidation temperature.

Investigation of Defects in Hydrogen-Saturated Titanium by Means of Positron Annihilation Techniques

2015 ◽  
Vol 365 ◽  
pp. 232-236 ◽  
Author(s):  
Roman S. Laptev ◽  
Andrey M. Lider ◽  
Yuriy S. Bordulev ◽  
Viktor N. Kudiiarov ◽  
Georgy V. Garanin ◽  
...  
Keyword(s):  
Defect Structure ◽  
Positron Lifetime ◽  
Pure Titanium ◽  
Doppler Broadening ◽  
Commercially Pure Titanium ◽  
Structure Investigation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Commercially Pure ◽  
Different Dimensions

This paper presents the results of a defect structure investigation in commercially pure titanium alloy after hydrogen charging in a gaseous atmosphere at the temperature of 873 K up to the concentration of 5.1 at. %. Structure of samples was studied by positron lifetime, Doppler broadening and X-ray diffraction spectrometry. Several processes, corresponding to the different ranges of hydrogen concentrations were revealed. It was shown that hydrogen, penetrating in the material, expands its crystal lattice, initiates formation of vacancy-like defects of different dimensions and reacts with the last ones, forming the defect-hydrogen complexes.

Bioactive Porous Film Produced on Titanium Substrate by Micro-Arc Oxidation

2008 ◽  
Vol 368-372 ◽  
pp. 1201-1202
Author(s):  
Q. Ma ◽  
Y.J. Wang ◽  
Cheng Yun Ning ◽  
Hai Mei Cheng ◽  
Zhao Yi Yin
Keyword(s):  
Pure Titanium ◽  
Titanium Substrate ◽  
Disodium Salt ◽  
Commercially Pure Titanium ◽  
X Ray Diffraction ◽  
Electrolytic Solution ◽  
Glycerol Phosphate ◽  
X Ray ◽  
Commercially Pure ◽  
Micro Arc Oxidation

Porous bioactive thin film on commercially pure titanium substrate was prepared by micro-arc oxidation (MAO) in electrolytic solution, which contained calcium acetate, β-glycerol phosphate disodium salt pentahydrate (β-GP) and lanthanum nitrate. The phases and microstructure of the bioactive films were examined by X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectrometer and electron probe microanalysis. The results showed that: (1) porous bioactive films with about 10μm were formed on titanium substrate by MAO; (2) phases of the thin films were hydroxyapatite, anatase and rutile; (3) elements of Ca, P, and Ti of films were identified by EDS.

scholarly journals EFFECT OF THERMAL OXIDATION ON THE CORROSION RESISTANCE OF CP-TI

2017 ◽  
Vol 23 (2) ◽  
pp. 135
Author(s):  
Shijing Lu ◽  
Kunxia Wei ◽  
Yan Wang ◽  
Jing Hu
Keyword(s):  
Corrosion Resistance ◽  
Thermal Oxidation ◽  
Pure Titanium ◽  
Immersion Test ◽  
Commercially Pure Titanium ◽  
X Ray Diffraction ◽  
X Ray ◽  
Commercially Pure ◽  
Different Temperatures ◽  
Cp Ti

<p class="AMSmaintext">Commercially pure titanium (CP-Ti) was subjected to thermal oxidation at different temperatures and times for determining the optimum oxidation conditions to obtain the optimum corrosion resistance. The phase constituents of the samples were determined by X-ray diffraction (XRD), the morphology of the surface was observed by SEM, and the corrosion behavior was investigated using immersion test by exposing the samples in HCl solutions with a concentration of 37%. The results showed that Rutile TiO<sub>2</sub> layer was formed on the surface of CP-Ti after thermal oxidation and the thickness of the TiO<sub>2</sub> layer increased with the treating temperature. Meanwhile, It was found that the optimum corrosion resistance to HCl was obtained while oxidizing at 700℃ for 330min～500min.</p>

Investigation of Commercially Pure Titanium Structure during Accumulation and Release of Hydrogen by Means of Positron Lifetime and Electrical Resistivity Measurements

2014 ◽  
Vol 880 ◽  
pp. 93-100 ◽  
Author(s):  
Yuriy S. Bordulev ◽  
Roman S. Laptev ◽  
Viktor N. Kudiiarov ◽  
Andrey M. Lider
Keyword(s):  
Electrical Resistivity ◽  
Positron Lifetime ◽  
Vacuum Annealing ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resistivity Measurements ◽  
Commercially Pure ◽  
Titanium Structure

In this work the goal was to study the behavior of titanium-hydrogen system with hydrogen concentration of 1 wt. % at high temperature vacuum annealing by means of positron lifetime (PL) spectroscopy and electrical resistivity measurements. The range of hydrogen concentrations under investigation requires the γ phase formation. The study is related with the X-ray diffraction (XRD) and thermal desorption spectra (TDS) analysis. The registered positron lifetime spectra were analyzed by multiexponential decomposition into two components. Correlation of changes of the parameters of the PL spectrum and the electrical resistivity is revealed in this paper.

Monotonic and cyclic behavior of the nitrogen ion-implanted commercially pure-titanium

2021 ◽  
Vol 15 (1) ◽  
pp. 7662-7670
Author(s):  
N. Ali ◽  
M.S. Mustapa ◽  
T. Sujitno ◽  
T.E. Putra ◽  
Husaini .
Keyword(s):  
Material Properties ◽  
Room Temperature ◽  
Pure Titanium ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Cyclic Behavior ◽  
Strain Hardening Exponent ◽  
Commercially Pure Titanium ◽  
Commercially Pure ◽  
Nitrogen Ion

This research aims to study the behavior of monotonic and cyclic plastic deformation on commercially pure titanium which has undergone surface treatment using the nitrogen ion implantation method. The doses of 2.0×1017 ions/cm2 and the energy of 100 keV were used to implant the nitrogen ions into the CpTi. Monotonic properties tests were performed in a laboratory air and at room temperature using ASTM E8 standard specimens. Fatigue and corrosion fatigue tests were conducted in a laboratory  air and in artificial saline solutions, at room temperature using ASTM 1801-97 specimens. Tensile tests were carried out with constant displacement rate and fatigue tests were carried under fully-reversed with stress-controlled conditions with stress amplitudes 230, 240, 250, 260, 270 and 280 MPa. The results showed the material properties of monotonic behavior for CpTi and Nii-Ti; tensile strength (σu) of 497 and 539 MPa and for 0.2% offset yield strength (σy) of 385 and 440 MPa, respectively and of cyclic behavior; cyclic strength coefficient (k’) of 568.41 and 818.64 and cyclic strain hardening exponent (n’) of 0.176 and 0.215, respectively. This study has succeeded in producing useful new material properties that will contribute to the field of material science and engineering.

Mechanochemical reactions in the system FeTiO3–Si

1998 ◽  
Vol 13 (12) ◽  
pp. 3499-3503
Author(s):  
Ying Chen ◽  
J. S. Williams
Keyword(s):  
Room Temperature ◽  
Reaction Rate ◽  
Thermal Analyses ◽  
Mechanochemical Reaction ◽  
X Ray Diffraction ◽  
Reaction Stage ◽  
X Ray ◽  
Powder Composition ◽  
Si Content ◽  
Mechanochemical Reactions

Mechanochemical reactions in the system FeTiO3 –Si have been investigated as functions of the powder composition and milling conditions, using x-ray diffraction and thermal analyses. Reduction reactions of FeTiO3 by Si were observed during room-temperature milling with the formation of α–Fe, amorphous SiOx, nanocrystalline TiO2, or intermetallic compounds, depending on the Si content. The mechanochemical reaction process consists of a mechanical activation stage and a reaction stage. Higher milling intensity leads to a shorter activation step and a higher reaction rate.

Ultrasonic Surface Mechanical Attrition of Commercially Pure Ti to Induce Nanocrystalline Surface Layer

2010 ◽  
Vol 442 ◽  
pp. 152-157 ◽  
Author(s):  
M. Mansoor ◽  
J. Lu
Keyword(s):  
Pure Titanium ◽  
Nanocrystalline Structure ◽  
Surface Mechanical Attrition Treatment ◽  
X Ray Diffraction ◽  
Annealed Condition ◽  
X Ray ◽  
Commercially Pure ◽  
Transmission Electron ◽  
Mechanical Attrition ◽  
Xrd And Tem

In the domain of incremental nanotechnology, surface mechanical attrition treatment is a technique which can transform superficial structure of a material to nanocrystalline without changing the chemical composition. This study is a part of the development and implementation of the technique by using ultrasonic vibrations. The material used is pure titanium in rolled and annealed condition. The nanocrystalline structure is characterized using X-ray diffraction (XRD), and transmission electron microscopy (TEM). The measured grain size is in the order of 5~60 nm. A correlation in the results of XRD and TEM is also discussed.

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