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.

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.

Microstructure and High-Temperature Oxidation of Ni-Si3N4 Composite Coatings by Pulse Electrodeposition

2015 ◽  
Vol 817 ◽  
pp. 421-425
Author(s):  
Kun Zhao ◽  
Wan Chang Sun ◽  
Chun Yu Miao ◽  
Hui Cai ◽  
Ju Mei Zhang ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Composite Coatings ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
Electro Deposition ◽  
X Ray ◽  
Crystallite Structure

Nickel matrix and Si3N4 micron particles were co-deposited on the aluminum alloy by pulse electro-deposition for high temperature performance. Meanwhile, the oxidation resistance was evaluated through the high temperature oxidation test. The phase structure, micrographs and components of the composite coatings were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) together with energy dispersive spectroscopy (EDS) respectively. The results indicated that Si3N4 particles were uniformly distributed across the coating and there were no pores and cracks or other defects at the coating/substrate interface. Ni-Si3N4 composite coatings are characterized by pyramidal micro-crystallite structure. The thickness of Ni-Si3N4 composite coatings were up to 80 μm for 2h. The results also revealed that the Ni-Si3N4 composite coatings presented better oxidation resistance than the pure Ni coating and aluminum alloy at high temperature. After oxidation at 673 K for 8h, the oxidation resistance of Ni-Si3N4 composite coatings presented the improved oxidation resistance behavior compared to pure Ni and the aluminum alloy, respectively.

Effect of B on the Microstructures and High Temperature Oxidation Resistance of a Nb-Si System In Situ Composite

2007 ◽  
Vol 546-549 ◽  
pp. 1489-1494 ◽  
Author(s):  
Ai Qin Liu ◽  
Shu Suo Li ◽  
Lu Sun ◽  
Ya Fang Han
Keyword(s):  
High Temperature ◽  
Oxide Scale ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Temperature Oxidation ◽  
X Ray ◽  
Solid Solution Strengthening ◽  
Arc Melting ◽  
The Matrix

Nb-16Si-24Ti-6Cr-6Al-2Hf-xB(x=0, 0.5, 1, 2, 4, 6) in situ composites were prepared by arc-melting. Microstructure and the effect of boron on 1250C oxidation resistance of the composites were investigated by scanning electron microscopy(SEM) and X-ray energy disperse spectrum(EDS) as well as X-ray diffraction(XRD). The experimental results showed that the high temperature oxidation resistance of the alloy was remarkably improved by adding proper amount of boron. This may be resulted from several beneficial roles of boron, i.e., boron improves the resistance of Nb5Si3 by solid solution strengthening, inhibits the diffusion of oxygen in the matrix, improves the adherence between the oxide scale and the substrate and increases the cracking resistance of the oxide scale.

In-Suit Synthesis (ZrB2-SiC)/Si High Temperature Oxidation Resistance Coating by Argon Arc Cladding

2014 ◽  
Vol 1035 ◽  
pp. 134-137
Author(s):  
Zhen Ting Wang ◽  
Shi Kui Zhu
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Graphite Electrode ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
Graphite Matrix ◽  
Clad Layer ◽  
In Suit

In order to overcome the occurrence of insufficient oxidation reaction, high temperature oxidation resistance (ZrB2-SiC)/Si composite coating was fabricated on the surface of graphite electrode by argon arc cladding, process using the Si, Zr and B4C power blends. The microstructure and phase composition of the clad layer were researched by means of scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The result shows that the coating consist of ZrB2 and SiC particles, The combination of the cladding layer and the graphite matrix results in kind of a continuous interface without visible defects. As the result of burning 60 min at 1573K, the oxidation weightlessness rate is 0.62%.

High temperature oxidation resistance of porous Ni–Cr–Fe materials

2020 ◽  
Vol 111 (4) ◽  
pp. 356-359
Author(s):  
Liang Wu ◽  
Yifeng Xiao ◽  
Xiuyan Xia ◽  
Jinwen Qian ◽  
Yuehui He
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
X Ray Diffraction ◽  
Powder Synthesis ◽  
Temperature Oxidation ◽  
X Ray ◽  
Mercury Intrusion ◽  
Parabolic Law ◽  
Reactive Powder

Abstract The oxidation behavior of porous Ni-Cr-Fe materials prepared by reactive powder synthesis with different open porosity was studied in air at 6008C, 800 8C and 1 0008C. The differences in surface morphology, phase and pore structure parameters between material oxidized and non-oxidized were characterized by means of scanning electron microscopy, X-ray diffraction analysis and mercury intrusion. The results show that the oxidation rate of the samples which were oxidized at 600 8C for 340 h, for 560 h at 800 8C and for 560 h at 1 000 8C were 0.00027%2 h-1, 0.0558%2 h-1, and 0.64412%2 h-1, respectively. All the oxidation kinetics curves obeyed the parabolic law, exhibiting excellent high temperature oxidation resistance.

ENHANCING HIGH-TEMPERATURE OXIDATION RESISTANCE OF TITANIUM ALLOY WITH KF110-B4C-Ag THROUGH LASER TECHNOLOGY

2021 ◽  
Author(s):  
ZHAO ZHANG ◽  
JIANING LI ◽  
ZHIYUN YE ◽  
CAINIAN JING ◽  
MENG WANG ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Mass Gain ◽  
Temperature Oxidation ◽  
Laser Technology ◽  
X Ray ◽  
Ta15 Titanium Alloy ◽  
Oxidation Resistant

In this paper, the high-temperature oxidation resistant coating on the TA15 titanium alloy by laser cladding (LC) of the KF110-B4C-Ag mixed powders was analyzed in detail. The scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDS) images indicated that a good metallurgy bond between the fabricated coating/TA15 was formed; also the fine/compact microstructure was produced after a cladding process. The oxidation mass gain of TA15 was higher than that of the coating after LC process, which were 3.72 and 0.91[Formula: see text]mg[Formula: see text]cm[Formula: see text], respectively, at 60[Formula: see text]h, greatly enhancing the high temperature oxidation resistance.

Microstructural Evolution during High-Temperature Oxidation of Ti2AlN Ceramics

2010 ◽  
Vol 65 ◽  
pp. 106-111
Author(s):  
Bai Cui ◽  
Rafael Sa ◽  
Daniel Doni Jayaseelan ◽  
Fawad Inam ◽  
Michael J. Reece ◽  
...  
Keyword(s):  
High Temperature ◽  
Microstructural Evolution ◽  
High Temperature Oxidation ◽  
Oxidation Mechanism ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
Oxidation In Air ◽  
Α Al2o3 ◽  
Increasing Temperature

Microstructural evolution of Ti2AlN ceramics during high-temperature oxidation in air has been revealed by X-ray diffraction (XRD), field emission gun scanning electron microscopy (FEGSEM), and energy-dispersive spectroscopy (EDS). After oxidation below 1200 °C, layered microstructures formed on Ti2AlN surfaces containing anatase, rutile, and α-Al2O3. Above 1200 °C, more complex layered microstructures formed containing Al2TiO5, rutile, α-Al2O3, and continuous void layers. With increasing temperature, anatase gradually transformed to rutile, and TiO2 reacted with α-Al2O3 to form Al2TiO5. Based on these microstructural observations, an oxidation mechanism for Ti2AlN ceramics is proposed.

A Porous TiO2 Coating with Vermiform Morphology Formed on Ti through Micro-Arc Oxidation

2013 ◽  
Vol 652-654 ◽  
pp. 1818-1821
Author(s):  
Zhen Fei Liu ◽  
Wei Qiang Wang ◽  
Min Qi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Temperature ◽  
Rutile Phase ◽  
Sodium Tetraborate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Porous Titania ◽  
Micro Arc Oxidation ◽  
Scanning Electron

A porous titania (TiO2) coating with vermiform slots was prepared on the Ti substrate through micro-arc oxidation (MAO) treatment using sodium tetraborate as electrolyte. Morphologies and phase structure were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Results show that the rutile phase increases and anatase decreases gradually with increasing MAO time. The electrolyte of sodium tetraborate has significant influence on the formation of vermiform coatings, which determine the corrosive patterning in the first stage during MAO processing. The evolution of vermiform morphology is proposed as followed: some corrosive pores appear on the surface before arcing; afterward, the adjacent micropores in the dense regions link each other due to the high temperature result from continuous arc action; then, the micropores grow up to big pits and combine with each other with increasing MAO treating time; finally, the vermiform morphology forms on the surface of Ti metal.

Microstructure and Oxidation of 55%Al-Zn-Si Hot-Dip Coatings Deposited on Low Carbon Steel at High Temperature

2011 ◽  
Vol 399-401 ◽  
pp. 1998-2003 ◽  
Author(s):  
Biao Zhou ◽  
Feng Jin ◽  
Qun Luo ◽  
Qian Li ◽  
Kuo Chih Chou
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Diffusion Rate ◽  
Intermetallic Layer ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
X Ray ◽  
Good Agreement

The high temperature oxidation and microstructure evolution of 55%Al-Zn-Si coated sheets were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD). After oxidation, the coatings consisted of three phases including ZnO, Fe2Al5, and FeAl from topcoat to the substrate. The different diffusion rate of Fe and Al result in forming voids at the interface of intermetallic layer and the substrate. A good agreement has been reached between the experimental data and the calculation from Chou diffusion model, which has a good predicted function. Moreover, the characteristic oxidation time and the apparent activation energy were obtained.

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