scholarly journals The Kinetics Of Ti-1Al-1Mn Alloy Thermal Oxidation And Charcteristic Of Oxide Layer

2015 ◽  
Vol 60 (2) ◽  
pp. 735-738 ◽  
Author(s):  
D. Klimecka-Tatar ◽  
S. Borkowski ◽  
P. Sygut

Abstract The main goal of the study was to carry out the treatment of cyclic oxidation of Ti alloy (Ti-1Al-1Mn) in air atmosphere. Based on measurements of mass gain of titanium alloy samples (Ti-1Al-1Mn) the kinetic oxidation curves during cyclic annealing were determined. The oxidized surface of the titanium alloy was carefully observed with optical microscopy equipment and the geometrical development, shape and surface morphology were defined. The phase composition of the obtained oxide layers on the Ti-alloy with qualitative analysis of the X-ray were defined. Since titanium alloys are among the most widely used metallic materials in dental prosthetics the corrosion measurements in a solution simulating the environment of the oral cavity were carried out. The results confirmed that the used titanium alloy easily covered with oxides layers, which to some extent inhibit the processes of electrochemical corrosion in artificial saliva solution.

RSC Advances ◽  
2018 ◽  
Vol 8 (34) ◽  
pp. 19181-19195 ◽  
Author(s):  
A. Madhan Kumar ◽  
M. A. Hussein ◽  
Akeem Yusuf Adesina ◽  
Suresh Ramakrishna ◽  
N. Al-Aqeeli

Surface treatment of metallic materials prior to the application of polymer coatings plays an important role in providing improved surface features and enhanced corrosion protection.


2013 ◽  
Vol 747-748 ◽  
pp. 844-849 ◽  
Author(s):  
Yue Fei ◽  
Xin Nan Wang ◽  
Zhi Shou Zhu ◽  
Jun Li ◽  
Guo Qiang Shang ◽  
...  

Ti-Mo-Nb-Cr-Al-Fe-Si alloy is a new metastable β titanium alloy with excellent combination of strength and ductility. The β grain-growth exponent and the activation energies for β grain growth for the investigated alloy at specified temperature were computed by the kinetic equations and the Arrhenius-type equation. The rate of β grain growth decreases with elongating solution treated time and increases with the increasing solution-treated temperature. The β grain-growth exponents, n, are 0.461, 0.464 and 0.469 at 1113, 1133 and 1153K, respectively. The β grain growth activation energy is determined to be 274 KJ/mol.


Author(s):  
S. Schellert ◽  
B. Gorr ◽  
H.- J. Christ ◽  
C. Pritzel ◽  
S. Laube ◽  
...  

AbstractIn this study, the effect of Al on the high temperature oxidation of Al-containing refractory high entropy alloys (RHEAs) Ta-Mo-Cr-Ti-xAl (x = 5; 10; 15; 20 at%) was examined. Oxidation experiments were performed in air for 24 h at 1200 °C. The oxidation kinetics of the alloy with 5 at% Al is notably affected by the formation of gaseous MoO3 and CrO3, while continuous mass gain was detected for alloys with the higher Al concentrations. The alloys with 15 and 20 at% Al form relatively thin oxide scales and a zone of internal corrosion due to the formation of dense CrTaO4 scales at the interface oxide/substrate. The alloys with 5 and 10 at% Al exhibit, on the contrary, thick and porous oxide scales because of fast growing Ta2O5. The positive influence of Al on the formation of Cr2O3 followed by the growth of CrTaO4 to yield a compact scale is explained by getter and nucleation effects.


Author(s):  
X. Ranz ◽  
T. Aslanian ◽  
L. Pawlowski ◽  
L. Sabatier ◽  
R. Fabbro

Abstract The hydroxyapatite Ca10(PO4)6OH2 (HAP) was plasma sprayed onto titanium alloy substrate. The samples having thickness of about 150 µm ware sprayed in a way to obtain two different content of crystalline HAP: 25 an 30 %. The coatings ware subsequently submitted to laser treatment with the CO2 laser. The treatment was carried out with different laser powers and scanning velocities and resulting thereof sample surface temperatures and the kinetics of the thermal fields ware monitored with a pyrometer. The XRD method enabled verification of the crystallinity state of HAP, content of amorphous calcium phosphate and the content of foreign phases. Optical microscope was used to check the microstructure and the depth of laser modified zone.


2019 ◽  
Vol 107 (2) ◽  
pp. 165-178
Author(s):  
Noura Mossaed Saleh ◽  
Ghada Adel Mahmoud ◽  
AbdelRahman AbdelMonem Dahy ◽  
Soliman Abdel-Fadeel Soliman ◽  
Refaat Mohamed Mahfouz

Abstract Kinetics of dehydration of unirradiated and γ-ray irradiated neodymium (III) acetate hydrate with 103 kGy total γ-ray dose absorbed in air atmosphere were studied by isoconversional nonisothermal method. The dehydration proceeds in two steps with the elimination of 0.8 and 0.4 mol of H2O, respectively. This result indicates that the investigated neodymium (III) acetate hydrate contains 1.2 mol of crystalline water in its structure. The dehydration reactions are best described by nucleation (A2 model) and gas diffusion (D4 model) for unirradiated and γ-ray irradiated samples, respectively. Analysis of the kinetic data using linear and nonlinear isoconversional methods showed that the apparent activation energy, Ea (kJ/mol) is dependent on the conversion degree, α, of the dehydration process. The Ea−α plots for both unirradiated and γ-ray irradiated neodymium (III) acetate hydrate showed that the dehydration is a complex process and contains multistep reactions. The results showed that γ-ray irradiation has a significant effect on the kinetics and thermodynamic parameters of the dehydration reaction. Powder X-ray diffraction showed that neodymium (III) acetate hydrate has a monoclinic system (SG P2/m) and no phase transformation was detected by γ-ray irradiation up to 103 kGy absorbed dose. The system maintains the same crystal structure before and after dehydration.


2018 ◽  
Vol 882 ◽  
pp. 142-153
Author(s):  
Daniel Gross ◽  
Andrea Heinz ◽  
Sven Amon ◽  
Trixi Meier ◽  
Ralf Schmand ◽  
...  

This paper aims to expand the use of CO2blasting by investigating a cryogenic deburring method for machined metallic materials. In advance to the actual deburring experiments, a streaming analysis based on high-speed video records was conducted for different blasting technologies, in order to gain deeper knowledge about their underlying active principles. For the titanium alloy Ti-6Al-4V and the stainless steel X6CrNiMoTi17-12-2, deburring experiments with three different blasting techniques were conducted and evaluated. It has been shown that cryogenic deburring has the potential to represent an alternative deburring solution for metals.


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