Influence of Reinforcing Phase on the Oxidation Model of ZrB2 Based Multi-Phase Ceramics

2014 ◽  
Vol 633 ◽  
pp. 189-192
Author(s):  
Jie Guang Song ◽  
Fang Wang ◽  
Xiu Qin Wang ◽  
Shi Bin Li ◽  
Gang Chang Ji
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Weight Change ◽  
Oxidation Mechanism ◽  
High Density ◽  
Change Rate ◽  
Protection Layer ◽  
Oxidation Model ◽  
Multi Phase

ZrB2, YAG and Al2O3 are widely applied because of some excellent performances, but ZrB2 is easily oxidized in the high-temperature air. To make the ZrB2 ceramics obtain better oxidation resistance, high-density ZrB2-YAG-Al2O3 ceramics were prepared. The oxidation mechanism of ZrB2-YAG-Al2O3 ceramics is investigated. When YAG-ZrB2 ceramics are exposed to air at temperatures from 1100°C¡æ to 1600°C¡æ, the weight change rate of YAG-ZrB2 ceramics is fleetly increased, the reacted speed of ZrB2 and O to form B2O3 and ZrO2 is more faster. The quantity of melted B2O3 is increased and carried to the surface, B2O3 is reacted with Al2O3 to form Al18B4O33. Al18B4O33 is melted and coated on the surface of ceramics to form protection layer for the oxidation resistance of ceramics at high temperature, which shows the similar with the influence of reinforcing phase on the oxidation model of ZrB2 based multi-phase ceramics.

Microstructures and Mechanical Properties in Ni3Si-Ni3Ti-Ni3Nb-Based Multi-Intermetallic Alloys

2004 ◽  
Vol 842 ◽  
Author(s):  
T. Takasugi ◽  
K. Ohira ◽  
Y. Kaneno
Keyword(s):  
High Temperature ◽  
Tensile Stress ◽  
Oxidation Resistance ◽  
Tensile Elongation ◽  
Intermetallic Alloy ◽  
Boron Addition ◽  
Intermetallic Alloys ◽  
Phase Intermetallic ◽  
Si Content ◽  
Multi Phase

ABSTRACTMicrostructure, high-temperature tensile deformation and oxidation property of Ni3Si-Ni3Ti-Ni3Nb multi-phase intermetallic alloys with a microstructure consisting of L12, D024 and D0a phases were investigated. The tensile stress as well as the tensile elongation of these multi-phase alloys increased with increasing Si content, i.e. the volume fraction of L12 phase in the wide range of test temperatures. 50-ppm boron addition to these multi-phase intermetallic alloys resulted in increased tensile stress and tensile elongation. The multi-phase intermetallic alloy with a high Si content had good oxidation resistance, and also the boron addition to this alloy resulted in enhanced oxidation resistance. From an overall evaluation of the properties examined, it was shown that the multi-phase intermetallic alloy, which has a high Si content and is composed of L12 matrix dispersed by D024 and D0a phases, had the most favorable properties as high-temperature mechanical and chemical materials.

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.

Improvement of high-temperature initial oxidation behavior of HR3C austenitic heat-resistant steel using silicon modification: experimental and first-principle study

2019 ◽  
Vol 116 (4) ◽  
pp. 401
Author(s):  
Tao Gao ◽  
Jian Wang ◽  
Nan Dong ◽  
Peide Han
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Oxidation Mechanism ◽  
Optical Emission ◽  
Energy Dispersive Spectrum ◽  
X Ray Diffraction ◽  
Initial Oxidation ◽  
Temperature Oxidation ◽  
The Matrix ◽  
The Stability

A novel silicon-containing austenitic stainless steel with excellent high-temperature initial oxidation resistance was prepared by adding 2.5 wt.% Si and modifying composition of the HR3C steels. Compared with HR3C steel, the oxidation resistance property of the steels containing silicon was markedly better at 800 °C. The high temperature oxidation mechanism of the steels containing silicon was analyzed by using scanning electron microscopy (SEM) with energy-dispersive spectrum (EDS) system, X-ray diffraction (XRD), glow discharge optical emission spectroscopy (GDOES), and first-principles calculations. The results show that the Si atom in the 22Cr-25Ni-2.5Si steel initially diffused from the matrix to the surface and then reacted with O2 to form SiO2. The SiO2 had an inhibiting effect on the diffusion of Cr from matrix resulting in maintenance of the stability of the oxidation film and improvement of the oxidation resistance as compared with the HR3C.

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.

Structure and High-Temperature Oxidation of Ti-Al-Nb and Ti-Al-Ta Intermetallics

2011 ◽  
Vol 465 ◽  
pp. 227-230 ◽  
Author(s):  
Dalibor Vojtěch ◽  
Tomáš Popela
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Oxidation Mechanism ◽  
High Strength ◽  
Vacuum Arc ◽  
Temperature Oxidation ◽  
Good Oxidation Resistance ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Work Structure

Ti-Al based intermetallics are prospective high-temperature materials showing low weight combined with a relatively high strength, high creep resistance and good oxidation resistance at high temperatures. Beside Ti and Al, these materials commonly contain other additives modifying their properties. In the present work, structure and oxidation resistance of two Ti-Al-Nb and Ti-Al-Ta alloys are studied. The alloys are prepared by vacuum arc melting and oxidation is conducted in air at 800-1000°C. It is found that there are significant differences in the structure depending on the ternary additive. There are also differences in oxidation behavior and these differences are discussed in relation to oxidation mechanism.

Fabrication and Oxidation-Resistance Property of Coated ZrB2-YAG-Al2O3 Multi-Phase Ceramics

2013 ◽  
Vol 544 ◽  
pp. 347-350
Author(s):  
Jie Guang Song ◽  
Fang Wang ◽  
Ming Han Xu ◽  
Shi Bin Li ◽  
Gang Chang Ji
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Protective Layer ◽  
Zirconium Diboride ◽  
Oxidation Temperature ◽  
Al2o3 Content ◽  
Precipitation Method ◽  
Composite Powders ◽  
Co Precipitation ◽  
Multi Phase

Zirconium diboride is widely applied because of some excellent performances. The results show the A1(OH)3-Y(OH)3/ZrB2 composite powders is prepared by a co-precipitation method, the shell-core structure A12O3-Y2O3/ZrB2 composite powders is prepared by sintering A1(OH)3-Y(OH)3/ZrB2 composite powders. The coating and density ZrB2-YAG-Al2O3 multi-phase ceramics is sintered at 1700°C, 20MPa for 4min by using Al2O3-Y2O3-80wt%ZrB2 composite powders, the oxidation weight is increased with increasing the oxidation temperature, however, the oxidation weight is decreased with increasing the YAG-Al2O3 content. ZrB2 reacted with O2 to form B2O3, and B2O3 is reacted with Al2O3 to form Al18B4O33, which is melted and coated on the surface of ceramics to form a protective layer for the oxidation resistance of ceramics at high temperature.

High Temperature Oxidation Protection of Multi-Phase Mo-Containing TiAl-Alloys by the Fluorine Effect

2012 ◽  
Vol 1516 ◽  
pp. 95-100 ◽  
Author(s):  
Alexander Donchev ◽  
Raluca Pflumm ◽  
Svea Mayer ◽  
Helmut Clemens ◽  
Michael Schütze
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Titanium Aluminides ◽  
Elevated Temperatures ◽  
Volume Fraction ◽  
Temperature Oxidation ◽  
Tial Alloys ◽  
Β Phase ◽  
Multi Phase ◽  
The Impact

ABSTRACTIntermetallic titanium aluminides are potential materials for application in high temperature components. In particular, alloys solidifying via the β-phase are of great interest because they possess a significant volume fraction of the disordered body-centered cubic β-phase at elevated temperatures ensuring good processing characteristics during hot-working. Nevertheless, their practical use at temperatures as high as 800°C requires improvements of the oxidation resistance. This paper reports on the fluorine effect on a multi-phase TiAl-alloy in the cast and hot-isostatically pressed condition at 800°C in air. The behavior of the so-called TNM material (Ti-43.5Al-4Nb-1Mo-0.1B, in at %) was compared with that of two other TiAl-alloys which are Nb-free and contain different amounts of Mo (3 and 7 at%, respectively). The oxidation resistance of the fluorine treated samples was significantly improved compared to the untreated samples. After fluorine treatment all alloys exhibit slow alumina kinetics indicating a positive fluorine effect. Results of isothermal and thermocyclic oxidation tests at 800°C in air are presented and discussed in the view of composition and microstructure of the TiAl-alloys investigated, along with the impact of the fluorine effect on the oxidation resistance of these materials.

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.

Study on the Oxidation and Electrical Resistivity of Reaction-Bonded Silicon Carbide at High Temperature

2007 ◽  
Vol 544-545 ◽  
pp. 475-478
Author(s):  
Zhen Lin Lu ◽  
Hui Xie ◽  
Ji Qiang Gao ◽  
Zhi Hao Jin
Keyword(s):  
Silicon Carbide ◽  
Electrical Resistivity ◽  
Weight Gain ◽  
High Temperature ◽  
Oxidation Resistance ◽  
Oxidation Behavior ◽  
Oxidation Mechanism ◽  
Parabolic Curve ◽  
Sic Particles ◽  
The Relationship

The oxidation behavior and electrical resistivity of reaction-bonded silicon carbide (RB-SiC) at high temperature (900 °C) had been studied in this paper. The results showed that the weight of RB-SiC would be increased when it was oxidized at 900. The relationship between the weight-gain of RB-SiC and oxidation times followed the parabolic curve. The oxidation resistance of RB-SiC at 900 could increased by the increase of SiC particles sizes. But the electrical resistivity of RB-SiC had not affected by the oxidation at 900. The oxidation mechanism of RB-SiC and the affecting factor on oxidation of RB-SiC were analyzed and discussed.

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