Evolution of Oxide Scales on Aluminide Coatings under Isothermal and Cyclic Conditions

2008 ◽  
Vol 595-598 ◽  
pp. 11-16 ◽  
Author(s):  
B. Bouchaud ◽  
J. Balmain ◽  
F. Pedraza
Keyword(s):  
High Temperature ◽  
Oxide Scale ◽  
Nodule Formation ◽  
Directionally Solidified ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
Growth Stresses ◽  
Aluminide Coatings ◽  
Ni3al Phase ◽  
Cycle 24

The oxide scale evolution with high temperature on CVD aluminide coatings deposited on a Directionally Solidified (DS) Ni-base superalloy is studied in this work. High temperature oxidation was carried out at 1100°C in air for 240 h under isothermal conditions and for 10 cycles (1 cycle = 24 h at 1100°C). The morphological and microstructural characterisation of the coatings has been performed using optical and electron microscopy as well as X-ray diffraction. Contrary to most of the results published in the literature, the rumpling phenomenon appears on the isothermally oxidised specimens whereas spallation, nodule formation and wrinkling of the oxide scale occur on the cyclically oxidised samples. The results are discussed in terms of the β-NiAl to γ’-Ni3Al phase transformation, the likely associated volume changes and of the growth stresses at high temperature.

Performance of Fe-33Ni-18Cr Alloy at High Temperature Oxidation

2020 ◽  
Vol 1010 ◽  
pp. 65-70
Author(s):  
Zahraa Zulnuraini ◽  
Noraziana Parimin
Keyword(s):  
Weight Gain ◽  
High Temperature ◽  
Oxide Scale ◽  
High Temperature Oxidation ◽  
Thick Layer ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
Oxide Particles ◽  
Lower Temperature

This paper investigates the performance of Fe-33Ni-18Cr alloy at high temperature oxidation. The samples were isothermally oxidized at three different oxidation temperatures, namely, 600 °C, 800 °C and 1000 °C for 150 hours. This alloy was ground by using several grits of SiC paper as well as weighed by using analytical balance and measured by using Vernier caliper before oxidation test. The characterization was carried out using scanning electron microscope (SEM) equipped with energy dispersive x-ray (EDX) and x-ray diffraction (XRD). The results show that, the higher oxidation temperatures, the weight gain of the samples were increase. Sample of 1000 °C indicate more weight gain compared to samples oxidized at 600 °C and 800 °C. The kinetic of oxidation of all samples followed the parabolic rate law. The surface morphology of oxide scale at lower temperature is thin and form a continuous layer, while at high temperature, the oxide scale develops thick layer with angular oxide particles.

Effects of Cr and Al on High Temperature Oxidation Resistance of Nb-Si System Intermetallics

2007 ◽  
Vol 546-549 ◽  
pp. 1485-1488 ◽  
Author(s):  
Shi Yu Qu ◽  
Ya Fang Han ◽  
Jin Xia Song ◽  
Yong Wang Kang
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Oxide Scale ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Oxidation Products ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
Scanning Electron

The effects of Cr and Al on high temperature oxidation resistance of Nb-Si system intermetallics have been investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and weight gain method. The results showed that the high temperature oxidation resistance can be substantially improved by proper Cr or Al addition. The further analysis revealed that Cr promotes the formation of CrNbO4 in scale and improve the adherence between the oxide scale and the substrate. It also found that Al improves the surface morphology of oxide scale and changes oxidation products by promoting the AlNbO4 formation.

scholarly journals Friction and Wear of Oxide Scale Obtained on Pure Titanium after High-Temperature Oxidation

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3764
Author(s):  
Krzysztof Aniołek ◽  
Adrian Barylski ◽  
Marian Kupka
Keyword(s):  
High Temperature ◽  
Oxide Scale ◽  
High Temperature Oxidation ◽  
Friction And Wear ◽  
High Carbon Steel ◽  
Oxide Films ◽  
Oxidation Temperature ◽  
Temperature Oxidation ◽  
Wear Ratio ◽  
Steel Balls

High-temperature oxidation was performed at temperatures from 600 to 750 °C over a period of 24 h and 72 h. It was shown in the study that the oxide scale became more homogeneous and covered the entire surface as the oxidation temperature increased. After oxidation over a period of 24 h, the hardness of the produced layers increased as the oxidation temperature increased (from 892.4 to 1146.6 kgf/mm2). During oxidation in a longer time variant (72 h), layers with a higher hardness were obtained (1260 kgf/mm2). Studies on friction and wear characteristics of titanium were conducted using couples with ceramic balls (Al2O3, ZrO2) and with high-carbon steel (100Cr6) balls. The oxide films produced at a temperature range of 600–750 °C led to a reduction of the wear ratio value, with the lowest one obtained in tests with the 100Cr6 steel balls. Frictional contact of Al2O3 balls with an oxidized titanium disc resulted in a reduction of the wear ratio, but only for the oxide scales produced at 600 °C (24 h, 72 h) and 650 °C (24 h). For the ZrO2 balls, an increase in the wear ratio was observed, especially when interacting with the oxide films obtained after high-temperature oxidation at 650 °C or higher temperatures. The increase in wear intensity after titanium oxidation was also observed for the 100Cr6 steel balls.

High-Temperature Oxidation of Stellite 12 Hardfacings: Effect of Mo on Characteristics of Oxide Scale

2018 ◽  
Vol 28 (1) ◽  
pp. 463-474 ◽  
Author(s):  
Amir Motallebzadeh ◽  
Shaikh Asad Ali Dilawary ◽  
Erdem Atar ◽  
Huseyin Cimenoglu
Keyword(s):  
High Temperature ◽  
Oxide Scale ◽  
High Temperature Oxidation ◽  
Temperature Oxidation ◽  
Stellite 12

Manganese Effect on Isothermal High Temperature Oxidation Behaviour of AISI 304 Stainless Steel

2008 ◽  
Vol 595-598 ◽  
pp. 1127-1134 ◽  
Author(s):  
Frédéric Riffard ◽  
Henri Buscail ◽  
F. Rabaste ◽  
Eric Caudron ◽  
Régis Cueff ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Oxide Scale ◽  
304 Stainless Steel ◽  
Initial Growth ◽  
Aisi 304 Stainless Steel ◽  
Protective Oxide ◽  
Temperature Oxidation ◽  
Aisi 304

Chromia-forming steels are excellent candidates to resist to high temperature oxidizing atmospheres because they form protective oxide scales. The oxide scale growth mechanisms are studied by exposing AISI 304 stainless steel to high temperature conditions in air, and the analyses were carried out by means of thermogravimetry and in situ X-rays diffraction. The in situ XRD analyses carried out during high temperature AISI 304 steel oxidation in air reveals the accelerated growth of iron-containing oxides such as hematite Fe2O3 and iron-chromite FeCr2O4, when the initial germination of the oxide layer contains the presence of a manganese-containing spinel compound (1000°C). When the initial growth shows the only chromia formation (800°C), hematite formation appears differed in time. Protection against corrosion is thus increased when the initial germination of manganese-containing spinel oxide is inhibited in the oxide scale.

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