scholarly journals Effect of high-temperature oxidation on the surface properties as applied to quenching of high-temperature bodies

2021 ◽  
Vol 2039 (1) ◽  
pp. 012024
Author(s):  
I A Molotova ◽  
A R Zabirov ◽  
V V Yagov ◽  
E V Terentyev ◽  
N N Antonov ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxide Layer ◽  
Surface Properties ◽  
High Temperature Oxidation ◽  
Thermal Effusivity ◽  
Contact Angles ◽  
Silver Coating ◽  
Simultaneous Formation ◽  
Temperature Oxidation ◽  
Before And After

Abstract This paper contains the results of studying the surface properties before and after high-temperature oxidation. For this, the plate zirconium samples with chromium, gold and silver coatings were prepared. Cut profiles of the samples were obtained to study the structure of coatings and the thickness of the oxide layer. The measurements of contact angles were carried out. The results showed that a porous heterogeneous oxide layer was formed on the samples after high-temperature oxidation. At the same time, the wettability of the samples was improved. The thickness of the oxide layer on the chrome-coated zirconium sample was the smallest. Using of electroplated silver coating for experiments involving heating to high temperatures seems inappropriate because it was damaged after the oxidation tests. It is assumed that the main factor which influence on the rise of the transition temperature to the intensive cooling regime during quenching is the appearance of the oxide layer, rather than the improved wettability and wickability. High-temperature oxidation leads to the simultaneous formation of an oxide layer with a low thermal effusivity and to an improvement in wettability, therefore the contribution of each of these two effects on quenching can be confused or overestimated.

scholarly journals High-Temperature Oxidation Properties and Microstructural Evolution of Nanostructure Fe-Cr-Al ODS Alloys

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 526
Author(s):  
Zhengyuan Li ◽  
Lijia Chen ◽  
Haoyu Zhang ◽  
Siyu Liu
Keyword(s):  
High Temperature ◽  
Oxide Layer ◽  
Microstructural Evolution ◽  
High Temperature Oxidation ◽  
Oxide Dispersion Strengthened ◽  
Al Alloy ◽  
Temperature Oxidation ◽  
X Ray ◽  
Plasma Sintering ◽  
Ods Alloys

The oxidation behavior and microstructural evolution of the nanostructure of Fe-Cr-Al oxide dispersion strengthened (ODS) alloys prepared by spark plasma sintering were investigated by high-temperature oxidation experiments in air at 1200 °C for 100 h. The formation of Al2O3 scale was observed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) line scans. The oxidation rate of Fe-Cr-Al ODS alloys is lower than that of conventional Fe-Cr-Al alloys, and the oxide layer formed on the Fe-Cr-Al alloy appeared loose and cracked, whereas the oxide layer formed on the Fe-Cr-Al ODS alloys was adherent and flat. This is due to the high density of dispersed nano-oxides hindering the diffusion of Al element and the formation of vacancies caused by them. In addition, the nano-oxides could also adhere to the oxide layer. Besides, the microstructure of the Fe-Cr-Al ODS alloy had excellent stability during high-temperature oxidation.

scholarly journals Effect of Nb addition on high-temperature oxidation behavior, oxide layer structure, and its exfoliation resistance of Ti-Nb Alloys

2020 ◽  
Vol 321 ◽  
pp. 05018
Author(s):  
Eri Miura-Fujiwara ◽  
Yuya Ogawa ◽  
Mitsuo Niinomi ◽  
Tohru Yamasaki
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Temperature ◽  
Oxide Layer ◽  
High Temperature Oxidation ◽  
Interfacial Microstructure ◽  
Temperature Oxidation ◽  
Transmission Electron ◽  
Cp Ti ◽  
Nb Addition

The authors proposed an oxide coating on Ti alloys for the dental abutment tooth, and they had reported that Ti–29Nb–13Ta–4.6Zr (TNTZ) alloy forms a dense oxide layer by high-temperature oxidation. On the other hand, CP Ti forms a multilayered oxide consisted of rutile monolayers and the void layer. This morphological change by alloying is supposed to be mainly caused by Nb addition in Ti since the dense oxide layer of TNTZ mainly consists of rutile TiO2 and TiNb2O7. Therefore, in this study, oxidation behaviors of various range of Nb content of Ti-xNb alloys (x = 1 ~ 32 mol%) were investigated, and exfoliation resistance was evaluated. And in this paper, the oxide/metal interfacial microstructure of oxidized CP Ti, TNTZ alloy, and Ti-Nb alloy was studied by a transmission electron microscopy (TEM) and by a scanning transmission electron microscopy with an electron dispersive spectroscopy (STEM-EDS). The cross-sectional observations suggested that the substrate was gradually oxidized during heat treatment, and nucleation and grain growth of TiO2 and TiNb2O7 proceed at the metal/oxide interface. Consequently, the gradual oxidation process in TNTZ and Ti-Nb alloys could lead to its continuous interfacial microstructure and dense oxide structure, which can achieve high exfoliation resistance.

Oxidation of Tantalum Nitride

2013 ◽  
Vol 761 ◽  
pp. 125-129 ◽  
Author(s):  
Kazuya Hamaguchi ◽  
Tomoyuki Tsuchiyama ◽  
Junichi Matsushita
Keyword(s):  
High Temperature ◽  
Oxide Layer ◽  
Human Body ◽  
Body Fluid ◽  
High Temperature Oxidation ◽  
Tantalum Oxide ◽  
Mass Gain ◽  
Tantalum Nitride ◽  
Oxidation Temperature ◽  
Temperature Oxidation

Tantalum (Ta) can be use a suture for operation and implant material in order not to react with body fluid and stimulate a human body. In this study, the stable oxide of a tantalum, tantalum oxide layer produced by oxidation of the tantalum nitride, TaN powders by high temperature oxidation were investigated in order to determine the possibility of its a distributed aid for biomaterial composite such as an artificial root etc. The sample, TaN powder oxidized at high temperature exhibited a steady mass gain with increasing oxidation temperature. Based on the results of the XRD, tantalum oxide, Ta2O5 was detected on the samples. It is considered, the TaN showed a good oxidation film produced by high temperature oxidation.

High Temperature Oxidation Behavior of (Ti, Al) C Ceramic Coatings on Carbon Steel Prepared by Electrical Discharge Coating in Kerosene

2011 ◽  
Vol 189-193 ◽  
pp. 186-192 ◽  
Author(s):  
Guo Liang Li ◽  
Xiao Hua Jie ◽  
Ling He
Keyword(s):  
High Temperature ◽  
Carbon Steel ◽  
Electrical Discharge ◽  
High Temperature Oxidation ◽  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Compact Structure ◽  
Temperature Oxidation ◽  
Before And After ◽  
High Temperature Oxidation Behavior

Multi-component metal ceramic coating（Ti, Al）C was prepared on the 0.45% carbon steel by electrical discharge coating (EDC) in a hydrocarbon medium. The coating of the samples before and after oxidation was analyzed by different methods including X-ray diffraction (XRD), scanning electron spectroscopy (SEM) and energy disperse spectroscopy (EDS).The thermogravimetric technique was used to approximate the kinetics of oxidation of the coated and the uncoated samples.The results indicated that the thickness of the coating was about 20μm, and the composition of the ceramic coating mainly consisted of (Ti, Al) C and a little Ti3AlC. An oxide film with compact structure formed after 600°C oxidation for 200h, and it was mainly composed of Al2O3and TiO2, which inhibited further oxygen diffusion into the coating. The (Ti, Al) C ceramic coating possessed slow oxidation rate and high temperature oxidation resistance.

scholarly journals High-Temperature Oxidation Performance of 4Cr4Mo2NiMnSiV Hot Die Steel

2021 ◽  
Author(s):  
Renheng HAN ◽  
Ning LI ◽  
Ziming BAO ◽  
Xinjian HU ◽  
Hexin ZHANG ◽  
...  
Keyword(s):  
High Temperature ◽  
Oxide Layer ◽  
High Temperature Oxidation ◽  
Metallic Matrix ◽  
Oxidation Mechanism ◽  
Surface Oxidation ◽  
Ambient Atmosphere ◽  
Temperature Oxidation ◽  
Die Steel ◽  
Hot Working Die Steel

A new type of hot working die steel was designed by using JMatPro, and high-temperature oxidation tests were carried out in the ambient atmosphere at 600 ℃ and 700 ℃. The heat treatment process and oxidation mechanism of the designed 4Cr4Mo2NiMnSiV steel were studied in detail. XRD, SEM and EDS were used to analyze the crystallographic phases, surface and cross-section morphologies of the oxide films. The results show that the main phases in the 4Cr4Mo2NiMnSiV steel were γ and α + δ. During the high-temperature oxidation, oxidation of the Fe outer layer and Cr inner layer occurred. After oxidation at 600℃, the surface oxidation layer comprised a monolayer with an uneven morphology. The surface oxide film had two layers after oxidation at 700℃. The outer oxide layer mainly contained Fe2O3 and Fe3O4, while the inner oxide layer mainly contained Cr2O3. The microstructure was relatively regular and had a significant effect on the protection of the metallic matrix. When oxidized, the 4Cr4Mo2NiMnSiV alloy steel easily formed protective layers, such as Cr2O3 and SiO2, so that the test steel had excellent oxidation resistance at high temperatures.

Influence Mechanism of Cu on High Temperature Oxidation Behavior of Titanium Alloys

2019 ◽  
Vol 944 ◽  
pp. 110-119 ◽  
Author(s):  
Hang Chen ◽  
Guang Bao Mi ◽  
Pei Jie Li ◽  
Chun Xiao Cao
Keyword(s):  
High Temperature ◽  
Grain Boundaries ◽  
Oxide Layer ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Temperature Oxidation ◽  
Oxidation Rates ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Oxidation Surface

The oxidation behavior and mechanism of Ti-Cu alloys (0≤w(Cu)≤20%) in the temperature range of 1000°C～1300°C are studied by thermogravimetric analysis(TGA) combined with SEM, EDS and XRD analysis methods. The results show that the oxidation rates of Ti-Cu alloys increase sharply when the temperature rises above 1000°C. The oxidation products have a three-layer structure, from the outside to the inside, which are dense outer oxide layer of TiO2, porous inner oxide layer of low valence oxide of Ti and Cu-enriched layer. With the increase of the temperature, the thicknesses of oxide layers of Ti-Cu alloy increase and the Cu-enriched phase increases gradually and melts. The melting Cu-enriched phase flows to the oxidation surface along the grain boundaries of the oxide layer. The high temperature oxidation resistance of Ti-Cu alloys declines with the increase of Cu content. The main reason is that more liquid Cu-enriched phase is formed and flows to the oxidation surface along the oxide grain boundaries in the Ti-Cu alloy, and Ti and O ions can diffuse more easily along the liquid Cu-enriched phase, which increases the oxidation rates.

scholarly journals High Temperature Oxidation Behaviors of CrNx and Cr-Si-N Thin Films at 1000 °C

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 540 ◽  
Author(s):  
Bih-Show Lou ◽  
Yue-Chyuan Chang ◽  
Jyh-Wei Lee
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Oxide Layer ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Temperature Oxidation ◽  
X Ray ◽  
Oxidation Test ◽  
Parabolic Rate ◽  
Oxidation Behaviors

The high temperature oxidation performance of nitride thin films has become an important issue when they are used as protective coatings on dry cutting tools or on die casting molds. In this study, the high temperature oxidation behaviors of CrNx and Cr-Si-N thin films were investigated at 1000 °C for 6 h in ambient air. The CrNx and Cr-Si-N thin films were prepared by a bipolar asymmetric pulsed direct-current (DC) magnetron sputtering system. Cr-Si-N films with silicon content ranging from 3.9 to 12.2 at.% were deposited by adjusting the Si target power. A thermogravimeter was adopted to study the oxidation kinetics of thin films. The weight gains were measured to calculate the parabolic rate constants of thin films. X-ray diffraction, X-ray mapping, and Auger electron spectroscopy were employed to study the microstructure and elemental redistributions of oxidized thin films. The as-deposited CrNx and Cr-Si-N thin films consisted of CrN and Cr2N mixed phases. The faceted Cr2O3 surface oxides, porous inner oxide layer, and oxygen-containing CrSi2 phases were found for the CrN film after oxidation test. On the other hand, the Cr-Si-N film containing 12.2 at.% Si showed a dense surface oxide layer and a thick and compact nitride layer, which indicates its best oxidation resistance. The high temperature oxidation resistance of Cr-Si-N thin films was improved by increasing Si content, due to the amorphous matrix contained nanocomposite microstructure and the formation of amorphous silicon oxide to retard the diffusion paths of oxygen, chromium, silicon, and nitrogen. The lowest parabolic rate constant of 1.48 × 10–2 mg2/cm4/h was obtained for the 12.2 at.% Si contained Cr-Si-N thin films, which provided the best oxidation resistance at 1000 °C for 6 h in this work. It should be noted that the residual tensile stress of thin film had a detrimental effect on the adhesion property during the oxidation test.

Isothermal Oxidation of Sintered β-FeSi2 in Air

2006 ◽  
Vol 522-523 ◽  
pp. 641-648 ◽  
Author(s):  
Makoto Nanko ◽  
Se Hun Chang ◽  
Koji Matsumaru ◽  
Kozo Ishizaki ◽  
Masatoshi Takeda
Keyword(s):  
High Temperature ◽  
Oxide Scale ◽  
Thermoelectric Properties ◽  
High Temperature Oxidation ◽  
Isothermal Oxidation ◽  
Amorphous Sio2 ◽  
Temperature Oxidation ◽  
Parabolic Law ◽  
Before And After ◽  
Significant Change

High-temperature oxidation of sintered β-FeSi2 doped with Mn and Co was evaluated at 800°C in air. Amorphous SiO2 was developed as an oxide scale. Granular ε-FeSi also appeared below the SiO2 scale as a result of consumption of Si in β-FeSi2. Growth of the oxide scale on doped FeSi2 followed a parabolic law and its rate was similar to oxidation of undoped samples. Thermoelectric properties of sintered β-FeSi2 were also evaluated before and after oxidation at 800°C for 7 days. There was no significant change in thermoelectric properties after high-temperature oxidation on β-FeSi2 sintered bodies.

Effect of Mo on the High Temperature Oxidation Behavior of Co-Al-W Based Alloys

2013 ◽  
Vol 747-748 ◽  
pp. 754-759 ◽  
Author(s):  
Fei Fan ◽  
Hao Sun ◽  
Di Zhao ◽  
Jiang Bo Sha
Keyword(s):  
High Temperature ◽  
Oxide Film ◽  
Oxide Layer ◽  
Outer Layer ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Oxidation Kinetic ◽  
Complex Oxide ◽  
Temperature Oxidation ◽  
High Temperature Oxidation Behavior

2 at.% and 4 at.% Mo were added to Co-9Al-9W-2Ta-0.02B alloy to replace W (hereafter referred to as the alloys of 2Mo and 4Mo, respectively; Mo-free alloy was referred to as the 0Mo alloy). The effects of Mo additions on the high temperature oxidation behavior of the alloys at 800 °C in air have been studied. The results indicated that, after oxidation in air at 800 °C for 100 h, the oxide film of the 0Mo alloy remained intact, but the cracking and spallation of the oxide film took place in the alloys of 2Mo and 4Mo. Oxidation kinetic curves revealed weight gain per unit area of the 0Mo alloy was 36.86 mg·cm-2, which was lower than that of the alloys of 2Mo (65.16 mg·cm-2) and 4Mo (48.54mg·cm-2). These suggested that the 0Mo alloy displayed superior oxidation resistance compared to the alloys of 2Mo and 4Mo caused by the formation of volatile MoO3 oxide, and sharp compressive stress formed in the outer layer during the oxidation. The oxide layer was composed of three layers of the Co3O4 + CoO outer layer, middle complex oxide layer containing Co, Al and W (Mo), inner Al2O3 layer and γ/Co3W zone adhere to the γ/γ' substrate.

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