Oxidation Behaviour of Zirconia-Sialon Composites

1992 ◽  
Vol 287 ◽  
Author(s):  
Yibing Cheng ◽  
Derek P. Thompson
Keyword(s):  
Structural Change ◽  
Oxidation Resistance ◽  
Diffusion Rate ◽  
Oxidation Behaviour ◽  
Oxidation Performance ◽  
Zirconia Phase ◽  
O Phase

ABSTRACTIn yttria densified ZrO2-sialon composites, an increase in β′:O′-sialon ratio results in a structural change in the zirconia phase because an increasing amount of nitrogen dissolves in the zirconia structure as the overall composition becomes increasingly nitrogen rich. Both ZrN and nitrogen-containing zirconia (N-ZrO2) are observed in the β′-ZrO2 composite and these phases show a poor oxidation performance above 600°C. However, the introduction of small amounts of O′ phase into the β′-ZrO2 composite has provided an effective oxygen-rich barrier to reduce the diffusion rate of nitrogen in zirconia and therefore O′-β′-ZrO2 composites showed superior oxidation resistance compared with β′-ZrO2 materials at temperatures between 600 and 1200°C.

Effect of Reactive Elements and Microstructure of Steel on High Temperature Oxidation Behaviour of Ferritic Stainless Steels

2010 ◽  
Vol 297-301 ◽  
pp. 1354-1361
Author(s):  
Hisao Fujikawa
Keyword(s):  
Stainless Steels ◽  
Diffusion Rate ◽  
Austenite Phase ◽  
Oxidation Behaviour ◽  
Temperature Oxidation ◽  
Ferritic Stainless Steels ◽  
Transmission Electron ◽  
Oxidation Performance ◽  
C And N ◽  
Stabilizing Element

The effect of different carbonitride forming elements on the oxidation performance of a 17Cr steel has been investigated. Whilst C and N are shown to have deleterious effects on the formation of protective oxides on unstabilised steel, a relationship has been found between the strength of the carbonitride former and the relative improvement in the oxidation performance. Furthermore, the appearance of the austenite phase has harmful influence on the oxidation resistance of the ferritic steel because the diffusion rate of Cr, Fe and so on is much slower in the austenitic structure than in the ferritic structure. The improvement is the most pronounced when the stabilizing element is Zr. The formation of the scale observed using transmission electron microscopy has been shown to be strongly controlled by the inward diffusion of the oxidant.

Cyclic Oxidation Performance of Si-Aluminide/MCrAlY Coating on Ni-Base GTD-111 Superalloy

2017 ◽  
Vol 889 ◽  
pp. 159-164
Author(s):  
K. Shirvani ◽  
S.V. Miraboutalebi
Keyword(s):  
Oxidation Resistance ◽  
Cyclic Oxidation ◽  
Oxidation Behaviour ◽  
Test Results ◽  
Mcraly Coating ◽  
Mcraly Coatings ◽  
Silica Scale ◽  
Spray Technique ◽  
Oxidation Performance ◽  
Metal Spray

A slurry aluminising process was utilised to produce duplex Si-modified aluminide MCrAlY coatings for superalloy GTD-111. MCrAlY coating was applied by means of high velocity oxy-fuel (HVOF) metal spray technique. Cyclic oxidation behaviour of the aluminide/MCrAlY coating were compared with plain MCrAlY coating. Oxidation performance of the coated samples was investigated by exposing samples to 1 h cyclic oxidation at 1100 °C. Oxidation test results demonstrate the Si-aluminide/MCrAlY coating exhibited much better oxidation resistance than the the uncoated superalloy due to the superior oxidation resistance of the alumina-silica scale at 1100 °C.

Isothermal Oxidation Behavior of a New Directionally Solidified Ni-Base Superalloy in Air at Different Temperature

2010 ◽  
Vol 654-656 ◽  
pp. 538-541
Author(s):  
Lei Wang ◽  
Yan Huang ◽  
Zhuo Zhao ◽  
Yang Liu ◽  
Jian Tao Wu ◽  
...  
Keyword(s):  
Oxidation Resistance ◽  
Oxidation Behavior ◽  
Isothermal Oxidation ◽  
Oxidation Behaviour ◽  
Diffusion Activation Energy ◽  
Directionally Solidified ◽  
Temperature Range ◽  
Parabolic Law ◽  
Diffusion Activation ◽  
Base Superalloy

The isothermal oxidation behaviour under static atmosphere of a new directionally solidified Ni-base superalloy was investigated. The results showed that the oxidation kinetics curves of the alloy follow parabolic law in the temperature range of 750-950°C. The diffusion activation energy Q is to be about 244.86 kJ•mol-1 and the oxidation within this temperature range is mainly controlled by Cr3+ diffusion among Cr2O3 oxidation film. The oxidation resistance grade of the alloy is perfect anti-oxidation within 750-850°C, and anti-oxidation within 900-950°C. The oxidation film can be divided into TiO2, Cr2O3+TiTaO4+NiCr2O4, Al2O3 and TiN layers, from the surface to inside. Priority oxidation and the inside oxidation of Al are considered with the oxidation of Ti and the depletion of Cr, and it is the key point for the improving of oxidation resistance.

Examinations on the Oxidation Resistance of Innovative Carbon Based Materials

2008 ◽  
Vol 59 ◽  
pp. 92-95
Author(s):  
Hans Klemens Hinssen ◽  
Rainer Moormann ◽  
Bärbel Schlögl ◽  
A. Centeno
Keyword(s):  
Oxidation Resistance ◽  
High Purity ◽  
Temperature Treatment ◽  
Oxidation Behaviour ◽  
Oxidation Rates ◽  
High Oxidation ◽  
High Oxidation Resistance ◽  
Future Work ◽  
Carbon Based

An overview on parameters influencing the oxidation behaviour of carbon based materials in oxidizing gases is presented in order to support the development of advanced carbon containing materials with high oxidation resistance. Facilities for testing the oxidation behaviour, as operated in FZJ, are explained. Results of exemplary oxidation tests in air at 700°C on diverse new developed materials are presented: Ti and Zr dopings and coatings were found less efficient, whereas Si coatings/dopings significantly reduce oxidation rates. Low oxidation rates of 3D-CFCs without doping/coating, which were manufactured under temperature treatment of > 2200°C and used high purity starting materials, point out the relevance of the latter parameters. Future work on oxidation resistance of carbon based materials is shortly discussed.

Review of Several Studies on High Temperature Oxidation Behaviour and Mechanism of Austenitic Stainless Steels

2011 ◽  
Vol 312-315 ◽  
pp. 1097-1105
Author(s):  
Hisao Fujikawa
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Oxide Scale ◽  
Oxidation Resistance ◽  
Stainless Steels ◽  
High Temperature Oxidation ◽  
Austenitic Stainless Steels ◽  
Oxidation Behaviour ◽  
Oxide Interface ◽  
Temperature Oxidation

Three studies on the oxidation behaviour of austenitic stainless steels were described in the present paper. (1) High temperature oxidation behaviour and its mechanism in austenitic stainless steels with high silicon: Sulfur contained as impurity in steel showed a harmful influence to the oxidation resistance of 19Cr-13Ni-3.5Si stainless steels. It was found that the abnormal oxidation was caused from the surroundings of MnS inclusions. (2) Effect of a small addition of yttrium on high temperature oxidation resistance of Si-containing austenitic stain less steels: The oxidation resistance of 19Cr-10Ni-1.5Si steels was improved remarkably even with only 0.01%Y addition, which is the same concentration as added for de-oxygenation. Y was enriched at the grain boundary of oxide scale and metal-oxide interface. It was suggested that Y-containing steels shoed good oxidation resistance, because the enriched Y at the grain boundary and metal-oxide interface prevented the diffusion of iron and oxygen ions through the oxide scale. (3) Effect of grain size on the oxidation behaviour of austenitic stainless steels: Type 304, 316 and 310 steels with finer grain size showed better oxidation resistance than those with coarser grain size at 850°C. The oxide scale of steels with coarser grain size easily spalled during the cooling process.

Oxidation Behaviour of Nickel-Based Alloys Containing High Re Contents Comparable to the Third Generation Nickel-Based Superalloys

2004 ◽  
Vol 449-452 ◽  
pp. 349-352 ◽  
Author(s):  
Yoshinori Murata ◽  
Masahiko Morinaga ◽  
Ryokichi Hashizume
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Oxidation Behaviour ◽  
The Other ◽  
Third Generation ◽  
Temperature Oxidation ◽  
Oxidation Test ◽  
Al Content ◽  
The Third

In order to elucidate the Re effect on oxidation resistance, a high-temperature oxidation test was conducted with two groups of Ni-based superalloys. One group of alloys was characterized by 10mol%Al content (10-Al series). The other group of alloys was characterized by 15mol%Al content (15-Al series). The oxidation resistance decreased clearly with increasing Re content in the 10-Al series alloys, but did not in the 15-Al series alloys.

The Effect of Coatings on the Cyclic Oxidation Behaviour of Ti6Al4V at 750°C

2011 ◽  
Vol 393-395 ◽  
pp. 428-435 ◽  
Author(s):  
Ying Yuan Teng ◽  
Qian Chen ◽  
Li Xin
Keyword(s):  
Oxidation Resistance ◽  
Cyclic Oxidation ◽  
Oxidation Behaviour ◽  
Ti6al4v Alloy ◽  
Effective Protection ◽  
Tialsin Coating ◽  
Substrate Alloy

For improvement of the cyclic oxidation resistance of the Ti6Al4V alloy, multi-layered Ti50Al50N/Ti70Al30N and mono-layered Ti60Al30Si10N were deposited on the alloy. It has been found that both coatings provide an effective protection for substrate alloy and the cyclic oxidation resistance of the TiAlSiN coating is better. After cyclic oxidation, it has been found that N diffused into the substrate alloy.

Long-Term, Cyclic Oxidation Behaviour of Alumina- and Chromia-Forming Alloys

2005 ◽  
Vol 237-240 ◽  
pp. 1107-1114 ◽  
Author(s):  
Renata Bachorczyk Nagy ◽  
Richard J. Fordham
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Oxide Scale ◽  
Water Vapour ◽  
Oxidation Resistance ◽  
Cyclic Oxidation ◽  
Oxidation Behaviour ◽  
Reactive Elements ◽  
Funded Project

The oxidation resistance behaviour of a number of surface-treated FeCrAl commercial alloys and some model alloys of well-defined composition, incorporating a range of reactive elements in trace amounts, has been studied under thermal cyclic conditions in air with and without additions of water vapour. Additions of reactive elements such as Zr, La, Y, Hf modify the oxidation resistance behaviour of FeCrAl-alloys by improving the scale adherence and consequently may extend the lifetime of FeCrAl steels. The presence of the water vapour can affect oxidation in a number of different ways. Our results may indicate that high content of water vapour can cause the lives of such alloys to be decreased. This work forms part of a larger European-funded project to evaluate physical properties, microstructural features, oxidation/corrosion resistance and lifetime improvement. The correlation between alloy parameters and lifetime; as well as the modeling of oxide scale behaviour as function of cycling conditions is also studied.

scholarly journals Investigation on Optimal Ta/Cr Ratio of a Single Crystal Ni-Base Superalloy in View of the Isothermal Oxidation Behavior

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1421
Author(s):  
Jianxiu Chang ◽  
Wenhao Feng ◽  
Wenwen Zhao ◽  
Hongmin Jia ◽  
Yanming Liu ◽  
...  
Keyword(s):  
Single Crystal ◽  
Oxidation Resistance ◽  
Oxidation Behavior ◽  
Isothermal Oxidation ◽  
Nitride Layer ◽  
Oxidation Products ◽  
Competitive Growth ◽  
X Ray Diffraction ◽  
Al2o3 Layer ◽  
Oxidation Performance

The relative content of strengthening element tantalum (Ta) and oxidation-resistant element chromium (Cr) is an essential value for superalloys to obtain an excellent combination of oxidation resistance and mechanical properties. In the present paper, the isothermal oxidation behavior of several single crystal Ni-base superalloys with different Ta/Cr (wt. %, similarly hereinafter) ratios at 1000 °C in static air has been systematically investigated to explore the optimal Ta/Cr for excellent oxidation resistance. A detailed microstructure study using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and an electro-probe microanalyzer (EPMA) was performed to reveal the oxidation products and mechanisms. For all alloys, a three-layer structured scale consisting of an outer (Cr, Al, Ti, Ni, Ta)-O layer, an inner Al2O3 layer and an inner nitride layer was formed. As Ta/Cr increased, the amounts of Ta-containing products, cracks, holes and inner nitride increased. Meanwhile, the completeness of the Al2O3 layer got worse. It was shown that if Ta/Cr ≤ 0.5, Ta increased the growth rate of Cr2O3 via the doping effect induced by Ta cations. If Ta/Cr > 0.5, Ta reduced the completeness of Cr2O3 through competitive growth of Ta2O5 and Cr2O3. A good oxidation performance can be expected with the value Ta/Cr ≤ 0.5.

Oxidation Resistance of Mild Steels Coated with Ce4+-Modified TiO2 Nanofilms

2007 ◽  
Vol 336-338 ◽  
pp. 1930-1932
Author(s):  
Z.M. Shi ◽  
W.G. Yu ◽  
G.J. Ji ◽  
Hai Zhou
Keyword(s):  
Stainless Steel ◽  
Oxidation Resistance ◽  
Double Layer ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Layer Number ◽  
Oxidation Test ◽  
Oxidation Performance ◽  
Oxidation Effect

The Ce4+-modified titania nanofilm was deposited onto mild steels by the sol-gel method. The effect of the film on protecting mild steels from oxidation was studied by means of oxidation test, SEM and XRD. It was found that the anti-oxidation effect is increased by Ce4+ modifying and with increasing layer number. When oxidized below 600 oC, the Ce4+-modified double-layer titania nanofilm possesses an excellent anti-oxidation performance that is comparable with that of the stainless steel.

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