scholarly journals Study on the Pre-Oxidation and Resulting Oxidation Mechanism and Kinetics of Mo-9Si-8B Alloy

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5309
Author(s):  
Cheng Wang ◽  
Qiuliang Li ◽  
Zhenping Guo ◽  
Xiangrong Li ◽  
Xiangyu Ding ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Cyclic Oxidation ◽  
Initial Period ◽  
Oxidation Mechanism ◽  
Protective Layer ◽  
Temperature Oxidation ◽  
Locking Mechanism ◽  
Kinetics Of

Molybdenum silicon boron alloy is regarded as the next generation of superalloy that is expected to replace nickel-based superalloys. However, the high-temperature oxidation resistance of Mo-Si-B alloy has always been an issue worth studying. In this study, Mo-9Si-8B alloy was prepared via a plasma oscillatory pressure sintering process and pre-oxidized at 1300 °C while maintaining a certain balance of mechanical and oxidation properties. The influence of the oxide protective layer on its performance at high temperature of 1150 °C was explored, the micro-mechanism of its performance and its failure mode of the hinge-locking mechanism was illustrated, and finally, its oxidation kinetics was inferred. In conclusion, pre-oxidized Mo-9Si-8B (at.%) alloy did play a role in delaying the oxidation process during the initial period of cyclic oxidation. However, with the increase of cyclic oxidation time, the improvement of high-temperature oxidation resistance was limited.

Application of Silicon for a Protection of Titanium against High-Temperature Oxidation

2005 ◽  
Vol 482 ◽  
pp. 243-246 ◽  
Author(s):  
Dalibor Vojtěch ◽  
Tomáš Kubatík ◽  
Hana Čížová
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Cyclic Oxidation ◽  
Oxidation Mechanism ◽  
Positive Influence ◽  
Surface Alloying ◽  
Temperature Oxidation

The paper describes a positive influence of silicon on the high-temperature oxidation resistance of titanium. Since silicon additions can be realized both by bulk and by surface alloying, the surface siliconizing techniques, as well as structure of the Si-rich layers, are illustrated. Furthermore, the high-temperature cyclic oxidation resistance of the surface siliconized titanium and of the TiSi2 alloy are compared to that of pure Ti and TiAl6V4 alloy, and the oxidation mechanism is discussed.

Effect of CrTiAlN Coatings on High-Temperature Oxidation Behavior of H13 Steel

2013 ◽  
Vol 544 ◽  
pp. 343-346
Author(s):  
Hao Zhang ◽  
Shu Wang Duo ◽  
Xiao Yan Fei ◽  
Xiang Min Xu ◽  
Ting Zhi Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Protective Layer ◽  
Hard Coatings ◽  
Bonding Layer ◽  
Closed Field ◽  
H13 Steel ◽  
Columnar Crystal ◽  
Temperature Oxidation

CrTiAlN hard coatings have been deposited on H13 steel for improving the oxidation resistance by Closed Field Unbalanced Magnetron Sputter Ion Plating (CFUMSIP). The phase components, surface and section morphology of H13 steel before and after oxidation were analyzed by XRD and SEM. The results showed that the columnar crystal film possesses three major parts, i.e., the internal Cr bonding layer, the intermediate CrN transition layer, the external CrTiAlN gradient coating. The selective oxidation of Cr element was found on the surface of uncoated H13 steel while oxidation, but a continuous protective layer was not formed because of low Cr content, finally a lot of alpha Fe2O3 particles took place on the surface of H13 steel owing to the oxidation of the matrix element. O element can diffuse much more easily through the coating and oxide scales at 800 °C, and spallation and cracks were not found during the oxidation. These results indicated that the CrTiAlN coating have excellent high-temperature oxidation resistance at 800 °C.

scholarly journals High Temperature Oxidation Behaviors of BaO/TiO2 Binary Oxide-Enhanced NiAl-Based Composites

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6510
Author(s):  
Bo Li ◽  
Ruipeng Gao ◽  
Hongjian Guo ◽  
Congmin Fan
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Oxidation Mechanism ◽  
High Tech ◽  
Slight Reduction ◽  
Application Process ◽  
Temperature Oxidation ◽  
Outward Diffusion ◽  
Resistance Performance

High temperature lubricating composites have been widely used in aerospace and other high-tech industries. In the actual application process, high temperature oxidation resistance is a very importance parameter. In this paper, BaO/TiO2-enhanced NiAl-based composites were prepared by vacuum hot-press sintering. The oxidation resistance performance of the composites at 800 °C was investigated. The composites exhibited very good sintered compactness and only a few pores were present. Meanwhile, the composite had excellent oxidation resistance properties due to the formation of a dense Al2O3 layer which could prevent further oxidation of the internal substrate; its oxidation mechanism was mainly decided by the outward diffusion of Al and the inward diffusion of O. The addition of BaO/TiO2 introduced more boundaries and made the Kp value increase from 1.2 × 10−14 g2/cm4 s to 3.3 × 10−14 g2/cm4 s, leading to a slight reduction in the oxidation resistance performance of the composites—although it was still excellent.

scholarly journals High Temperature Oxidation Behavior of New Martensitic Heat-Resistant Steel

2021 ◽  
Author(s):  
Ziming BAO ◽  
Renheng HAN ◽  
Yanqing ZHU ◽  
Hong LI ◽  
Ning LI ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxide Film ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Oxidation Mechanism ◽  
Resistant Steel ◽  
Temperature Oxidation ◽  
Heat Resistant Steel ◽  
Heat Resistant

The research focuses on the high temperature oxidation resistance of martensitic heat-resistant steel. A new type of martensitic heat-resistant steel was developed with the addition of Al and Cu, and the oxidation behavior of the new martensitic heat-resistant steel at 650 °C and 700 °C was analyzed. The high temperature oxidation kinetics curves of new martensitic heat-resistant steel at 650 °C and 700 °C were determined and plotted by cyclic oxidation experiment and discontinuous weighing method. XRD technique was applied to qualitatively analyze the surface oxide of the material after oxidation. The surface and cross-section morphology of the material were observed by field emission scanning electron microscope (SEM) and energy dispersive spectrometer (EDS), and the oxidation mechanism at high temperature was analyzed. The results show that the oxide film can be divided into two layers after oxidation at 650 ºC for 200 h. The outer oxide film is mainly composed of Fe and Cu oxides, and the inner oxide film is mainly composed of Al2O3, SiO2 and Cr2O3. After oxidation at 700 ºC for 200 h, the outer layer is mainly composed of Fe, Cu, Mn oxides, and the inner layer is mainly composed of Cr, Al and Si oxides. The addition of a small amount of Cu promotes the diffusion of Al and Si elements, facilitates the formation of Al2O3 and SiO2, and improves the high-temperature oxidation resistance of martensitic heat-resistant steel.

scholarly journals Effect of Mullite Film Layers on the High-Temperature Oxidation Resistance of AISI 304 Stainless Steel

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 880
Author(s):  
Jing Ma ◽  
Ning Wen ◽  
Ruiyang Wang ◽  
Jiangang Wang ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Cyclic Oxidation ◽  
304 Stainless Steel ◽  
Sintering Process ◽  
Aisi 304 Stainless Steel ◽  
Temperature Oxidation ◽  
Aisi 304

Protective coating is an effective way to extend materials’ high-temperature service life. In order to improve the high-temperature oxidation resistance of AISI 304 stainless steel, mullite films with different layers were successfully prepared by the sol-gel method and the sintering process on the surface of stainless steel. The effect of the film layers on the high-temperature oxidation resistance of stainless steel at 900 °C for 100 h was studied. The analysis results of oxidation kinetics, X-rays diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive analysis (EDS) show that Al1.4Si0.3O2.7 mullite film effectively improved the high-temperature oxidation resistance of stainless steel. The sample with three-layer mullite film has the best high-temperature oxidation resistance. The mass gain and oxidation spalling mass are only 4.6% and 34.5% of those of the uncoated sample after 100 h cyclic oxidation at 900 °C. A chromium oxide layer was formed at the interface of mullite film and the substrate during the sintering process. The generation of selective Cr2O3 scale was promoted at the cyclic oxidation stage so that the sample with three-layers has excellent high-temperature oxidation resistance.

Optimization of the Fluorine Effect for Improving the Oxidation Resistance of Tial-Alloys

2012 ◽  
Vol 706-709 ◽  
pp. 1061-1065 ◽  
Author(s):  
Alexander Donchev ◽  
Michael Schütze ◽  
Andreas Kolitsch ◽  
Rossen Yankov
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Inorganic Compounds ◽  
Oxidation Mechanism ◽  
Surface Region ◽  
Alumina Scale ◽  
Temperature Oxidation ◽  
Bulk Properties ◽  
Tial Alloys

The oxidation resistance of TiAl-alloys can be improved drastically by treating the surface of the components with small amounts of fluorine. The oxidation mechanism is changed. Hence, the formation of a fast growing mixed oxide scale on untreated alloys is suppressed. Instead a thin protective alumina scale is formed on samples after fluorine treatment. The different methods only influence the surface region of the components so that the bulk properties are not affected. Recent results achieved with F-containing inorganic compounds showed that the fluorine effect can be improved even further. TiAl-specimens were treated only with fluorine and with F-containing compounds in several ways and their performance during high temperature oxidation tests in air was investigated. Results of isothermal and thermocyclic oxidation tests are presented. The results are discussed in terms of a later use of the fluorine effect for technical applications.

scholarly journals Fabrication of High Temperature Oxidation Resistance Nanocomposite Coatings on PEO Treated TC21 Alloy

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 11 ◽  
Author(s):  
Kai Zhou ◽  
Faqin Xie ◽  
Xiangqing Wu ◽  
Shaoqing Wang
Keyword(s):  
Titanium Alloy ◽  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Oxidation Mechanism ◽  
Zro2 Nanoparticles ◽  
Temperature Oxidation ◽  
Composition Structure ◽  
Plasma Electrolytic ◽  
Peo Coatings

The effects of ZrO2 nanoparticles in a NaAlO2 electrolyte on the thickness, morphology, composition, structure, and high temperature oxidation resistance of plasma electrolytic oxidation (PEO) coatings on a TC21 titanium alloy were investigated. The coating thickness increased with increasing concentration of ZrO2 nanoparticles in the electrolyte, accompanied by a decrease in the porosity of the coating surface. The PEO coatings formed in the ZrO2 nanoparticle-free electrolyte were composed of Al2TiO5. ZrTiO4, m-ZrO2, and t-ZrO2 were detected in the PEO coatings produced by the electrolyte that contained ZrO2 nanoparticles, which indicated that the deposition mechanism of the nanoparticles was partly reactive incorporation. The high temperature oxidation resistance of the TC21 titanium alloy at 650 °C and 750 °C was improved by 3–5 times after PEO treatment. The oxidation mechanism involved oxygen diffusing inward to form an oxide layer at the interface of the PEO coating and substrate.

scholarly journals Effect of Al Content on the High-Temperature Oxidation Resistance and Structure of CrAl Coatings

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1434
Author(s):  
Jiaojiao Ma ◽  
Chuiyi Meng ◽  
Hui Wang ◽  
Xiujie He
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Harmful Effect ◽  
Antioxidant Properties ◽  
Oxidation Mechanism ◽  
Oxide Thickness ◽  
Temperature Oxidation ◽  
Al Content ◽  
Oxidation Behaviors

The oxidation behaviors of Cr, Cr93.4Al6.6, Cr58.1Al41.9, and Cr34.5Al65.5 coatings, deposited by using multi-arc ion plating technology, at high temperature were studied. The weight gain, oxide thickness, morphology, and phase composition of the coatings before and after oxidation were analyzed in detail. The results show that there is an Al content window available for tuning the oxidation behaviors of the CrAl-based coatings. The Cr93.4Al6.6 coating is considered to be most protective and can effectively improve the high-temperature oxidation resistance of the substrate; whereas, too high an Al content has a harmful effect on the antioxidant properties of the coatings. The oxidation mechanism of Cr and CrAl coatings were also discussed.

Improvement of Slurry Aluminide Coating on Ferritic Stainless Steel AISI430 for High-Temperature Oxidation Resistance

2015 ◽  
Vol 658 ◽  
pp. 86-90
Author(s):  
Piyorose Promdirek ◽  
Mack Boonpensin ◽  
Thanapon Rojasawasatien
Keyword(s):  
High Temperature ◽  
Surface Morphology ◽  
Oxidation Resistance ◽  
Oxidation Rate ◽  
High Temperature Oxidation ◽  
Aluminide Coating ◽  
Protective Layer ◽  
Growth Effect ◽  
Effect Of Temperature ◽  
Temperature Oxidation

One of the surface modification processes for high-temperature oxidation resistance is slurry aluminizing process, forming protective layer of alumina (Al2O3). However, several important parameters such as annealing times and temperatures should be intensively considered. The objective of this study is to improve the process of slurry aluminide coating of ferritic stainless steels type AISI430 (16%Cr) combat to high-temperature oxidation. The specimens were cut, then ground, and finally sprayed with slurry mixture (Al powder + polyvinyl alcohol (PVA)). They were annealed in Ar at 1100°C for 15 minutes in order to eliminate PVA and form aluminide on their suface. The protective layer Al2O3 was finally formed in the temperature range of 900-1100 °C for 15-60 minutes. The cyclic oxidation tests were performed at 1000 °C for 24 hours. The surface morphology were then examined by XRD, SEM equipped EDS. The results showed that all oxidation kinetics of coated specimens were parabolic. The oxidation rate of uncoated specimens was apparently higher than that of coated specimens. Comparing with all coated specimens, the oxidation rate decreased with the increasing temperature and annealing time. In this study, the coating process at 1100°C for 60 minutes exhibited the lowest oxidation rate due to the most complete layer of Al2O3. The surface morphology showed the formation of continuous layer of Fe2Al5 and Al2O3, acting as barrier layer to oxide growth. Effect of temperature and time on oxidation resistance were discussed in this study.

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