Effect Of Oxidation Temperature Research Articles

Effect of oxidation temperature on surface oxide film structure and corrosion resistance of 50 steel

The phase structure, thickness and corrosion resistance of oxidation film of 50 steel oxidized at 200∼600°C in an air furnace were studied by AES, SEM, XRD and EIS in this paper. The results show that the concentration of surface oxygen atoms of 50 steel shows a trend of rapidly increasing to a peak, maintaining stability for a distance, then decreasing, and finally stabilizing after oxidation treatment at different temperatures. The peak concentration of oxygen atoms and the stabilization distance are found to vary with the oxidation temperature. The oxidation activation energy is 25.2kJ/mol. With the increase of oxidation temperature, the oxide film composed of the outer Fe2O3 layer and the inner Fe3O4 layer is generated on the surface of 50 steel, and Fe2O3 is the primary constituent. Moreover, the corrosion of oxide film in NaCl solution is marked by anodic activation dissolution. The thermal oxidation samples demonstrate better corrosion resistance than the original samples with the increase of oxidation temperature, there is an upward trend in the self-corrosion potential, whereas a decreasing trend in the corrosion current density, and the capacitor-reactance arc radius is gradually increased. The maximum corrosion potential, the minimum corrosion current density and the largest capacitor-reactance arc radius are recorded at 600°C, at which temperature it has the best corrosion resistance.

Effect of oxidation temperature on physical properties of polycrystalline β-Ga2O3 grown by thermal oxidation of GaN in O2 ambient from 900 to 1400 °C

Effect of oxidation temperature on physical properties of polycrystalline β-Ga2O3 grown by thermal oxidation of GaN in O2 ambient from 900 to 1400 °C

Preparation of hollow carbon nanospheres from oxidation of spent tyre oil‐derived carbon black in air

AbstractHollow carbon nanospheres (HCNS) were prepared from carbon black (CB) derived from spent tyre pyrolysis oil. The pristine CB produced by partial oxidation of the pyrolysis oil in a drop tube furnace was subsequently oxidised in air in a fixed bed reactor to yield HCNS. The effect of oxidation temperature (300 to 700°C) and time (1 to 8 h) on the burn‐off (Bt) of the sample over the duration (t) of oxidation and average reaction rate (Rt) was assessed. The BET surface area and pore volume and the nanostructure of the HCNS samples obtained were characterised using N2 adsorption–desorption and high‐resolution transmission electron microscope (HRTEM) techniques, respectively. Higher temperature and longer oxidation time led to higher Bt. As Bt increased, the BET surface area and pore volume initially increased linearly due to the removal of the amorphous core and then decreased because of the collapse of the shell of the carbon nanostructure. At Bt of ~56%, the maximum BET surface area and pore volume of the HCNS were 383.2 m2 g−1 and 0.39 cm3 g−1, respectively, compared to ~19.5 m2 g−1 and 0.033 cm3 g−1 of the pristine CB. The HRTEM images indicate that the change in BET surface area corresponds to the formation of the HCNS, as the core of the CB particle was preferentially consumed to create a hollow structure. The formation of HCNS follows an internal oxidation model, which is characterised by rapid core consumption and relatively slow shell consumption.

Effect of oxidation temperature on Raman spectra of graphite samples

The recent work investigates the relationship between the characteristics of the Raman spectra and the oxidation temperature of thermal-treated graphite samples in air at various temperatures ranging from 200°Cto 800 °C. Our findings indicate that thermal oxidation of graphite in air leads to the enhancement of the 2D vibration pattern while reducing the intensity of the D vibration pattern. Moreover, we report that chemical reduction begins at 550 °C. Furthermore, our results demonstrate that thermal oxidation causes a decrease in the disorder within the samples.

Studies of the Induction Period of Canned Meat on the OXITEST Device

The article presents the results of testing the period of induction of the fat fraction of Stewed Beef canned meat in consumer packaging made of combined materials on the OXITEST device. The effect of oxidation temperature on the period of induction of canned meat was assessed. It is shown that as the temperature in the reactor increases, the induction period decreases. Data on the effect of temperature on the induction period can be used to calculate the shelf life of canned meats by extrapolation to the storage temperature. A comparative analysis of the dynamics of the induction period of canned meat during storage under normal conditions and at a temperature of 37°С showed an insignificant difference, which indicates the stability of canned food during long-term storage.

Effect of oxidation temperature on the properties of niobium in view of its biomedical applications

Effect of oxidation temperature on the properties of niobium in view of its biomedical applications

Effects of oxidation temperature on microstructure and spontaneous combustion characteristics of coal: A case study of Shendong long-flame coal

Effects of oxidation temperature on microstructure and spontaneous combustion characteristics of coal: A case study of Shendong long-flame coal

Effect of Oxidation Temperature on the Crystalline Phase of Polypropylene in Composites with Single-Walled Carbon Nanotubes

Effect of Oxidation Temperature on the Crystalline Phase of Polypropylene in Composites with Single-Walled Carbon Nanotubes

Effect of Ag addition on the oxidation behavior of CrAlN coating at elevated temperatures

Effect of Ag addition on the oxidation behavior of CrAlN coating at elevated temperatures

Effect of Oxidation Temperature on the Crystalline Phase of Polypropylene in Composites with Single-Walled Carbon Nanotubes

The effect of thermal oxidation on the crystalline phase of polypropylene in composites with single-walled carbon nanotubes has been studied. The composites are synthesized in propylene bulk using a homogeneous catalytic system rac-Me2Si(2-Me-4PhInd)2ZrCl2, activated by methylaluminoxane. The effect of thermal oxidation on thermophysical characteristics (the heat of melting and the melting temperature) measured by DSC and changes occurring in the polymer investigated by IR spectroscopy is studied. Changes in the structure of PP during thermo-oxidative degradation are studied by DSC at 140 and 170°С, that is, before and after melting of the samples. It is shown that the oxidized PP in the composites possesses a higher degree of crystallinity and a more perfect structure than the pure PP. At 170°С the effect of thermo-oxidative stabilization is observed only at low filling degrees (up to 3 wt %), in agreement with the TGA data. An analysis of IR spectra demonstrates that the presence of nanotubes in PP‑based composites during oxidation slows down the formation of oxygen-containing groups in the polymer. The conclusion is made that carbon nanotubes inhibit the thermal oxidation of polypropylene in the composites.

Study on the effects of oxidation temperature and ambient humidity on the terahertz spectroscopy characteristics of lignite

In this paper, the terahertz (THz) spectroscopy characteristics of lignite with different oxidation temperatures under different ambient humidity were investigated by terahertz time-domain spectroscopy (THz-TDS), and the mechanism was analyzed by combining the synchronous thermal analyzer. Results indicate that the refractive index of lignite has abnormal dispersion characteristics. THz waves have different transmission characteristics in lignite with different oxidation temperatures, which is reflected in the amplitude difference of time-domain and frequency-domain signals. The complex refractive index of lignite shows obvious oxidation temperature dependence, which is closely related to the physicochemical changes that occur during coal oxidation. Besides, ambient humidity has a significant effect on the THz spectroscopy measurement, which follows the Beer-Lambert law. As humidity increases, the amplitude of time-domain and frequency-domain signals decays linearly, while the complex refractive index increase linearly. Humidity has a similar effect on coal samples with different oxidation temperatures, which means that based on linear effects and good fit results, THz spectroscopy measurements in humid environments can be corrected by a simple linear empirical formula. The results of this study are helpful to study the spectroscopy characteristics of coal in the THz band, and provide guidance for the application of terahertz technology in coal mines.

Enhanced corrosion and wear resistance via thermal oxidation treatment on Zr-2.5Nb alloy for implant applications

Enhanced corrosion and wear resistance via thermal oxidation treatment on Zr-2.5Nb alloy for implant applications

Achieving high-strength W/W-10Cu joints by vacuum diffusion bonding with FeCoCu interlayer

Achieving high-strength W/W-10Cu joints by vacuum diffusion bonding with FeCoCu interlayer

Effect of Oxidation Temperature on Both the Fresnel Peak and Plasma Edge in the Optical Reflectivity Spectra of Graphite

Effect of Oxidation Temperature on Both the Fresnel Peak and Plasma Edge in the Optical Reflectivity Spectra of Graphite

Large area planar UV–Visible photodetectors using wide bandgap WO3−δ films

Large area planar UV–Visible photodetectors using wide bandgap WO3−δ films

Effects of oxidation temperature on the microstructure and tribological performance of Cu-based brake pad for high-speed train

The braking process of different speeds causes varying degrees of oxidation of the Cu-based brake pad, which will significantly affect its tribological performance. To simulate the process, Cu-based brake pads for high-speed trains were oxidized in atmospheric conditions at 25, 200, 400, and 600 °C, respectively. The microstructure and composition of the oxide layers were analyzed, and the tribological properties of the oxidized surfaces were investigated. The results show that, as the oxidation temperature rises, the surface oxides change from Cu 2 O + Fe 3 O 4 to CuO + Fe 3 O 4, along with the increase in the thickness and hardness of the oxide layer. The ablation of graphite particles is aggravated. The formed oxides and ablated graphite result in high friction coefficient and wear rate. Due to the loss of plastic deformation ability, the dominant wear mechanism of Cu-based brake pad transforms from delamination wear to abrasive wear with the increase of oxidation temperature. • Cu-based brake pads for high-speed trains were oxidized at different temperatures. • Surface oxides change from Cu 2 O + Fe 3 O 4 to CuO + Fe 3 O 4 as oxidation temperature rises. • Formed oxides and ablated graphite result in high friction coefficient and wear rate. • Wear mechanism transforms from delamination to abrasive with temperature increasing.

Production of cellulose nanocrystals extracted from Pennisetum purpureum fibers and its application as a lubricating additive in engine oil

In the present work, cellulose nanocrystals (CNCs) were successfully produced from the Pennisetum purpureum (PP) fibers through ammonium persulfate (APS) oxidation. The effect of oxidation temperatures (60, 70, and 80 °C) on the properties of CNCs was characterized. In addition, the influence of CNCs addition (0, 0.05, 0.1, and 0.2 wt%) on the lubrication properties of the base oil SAE 40 lubricant was also investigated. The characteristics of the CNCs were determined by using FT-IR, XRD, TEM, and TGA. The lubrication properties were evaluated using kinematic viscosity and viscosity index measurements. The optimal oxidation temperature was found at 60 °C which resulted in the needle-shaped CNCs particles with high crystallinity (66.56%), an average diameter (15 nm), and an average length (79 nm). The resulting CNCs exhibited higher thermal stability than the PP fibers. Both kinematic viscosity and viscosity index did not significantly change by increasing the CNCs contents. However, a slightly higher viscosity index was exhibited for 0.2 wt% CNCs compared to that of neat base oil SAE 40. The CNCs obtained had high potential as a reinforcing agent of nanocomposites and also as a bio-lubricating additive in engine oil.

Experimental study on surface characteristics and thermal conductivity of new zirconium alloy with oxide layer

The surface properties and thermal conductivity of oxide layer formed on the new zirconium alloy due to high temperature steam oxidation are studied in this paper. The thickness of oxide layer, surface wettability and thermal conductivity are measured. The effects of oxidation temperature and time on the wettability and thermal conductivity of zirconium alloy are analyzed. The results show that zirconium on the surface is fully oxidized to ZrO 2 , and the difference of surface wettability is caused by different surface morphology . The characteristics of oxide layer surface cracks will affect the surface wettability. At the same oxidation temperature, with increasing time duration, the size and number of oxide layer cracks increase. The change of thermal conductivity is the result of competition among factors such as the development of recrystallization process, the increase of oxide layer thickness and the influence of pores and cracks. • The surface properties and thermal conductivity of oxide layer formed by steam oxidation on zirconium alloy are studied. • Different oxidation time duation and oxidation temperature lead to different surface morphologyand hydrophilicity. • The change of the thermal conductivity is the result of competition among several factors. • A recommended value of the thermal conductivity of dense oxide layer formed on zirconium alloy is proposed .

Synergetic modification of industrial basic oxygen furnace slag and copper slag for efficient iron recovery

With the continuous exploitation of primary high-quality mineral resources, these resources could be gradually exhausted, so it is of great significance to recover iron-rich basic oxygen furnace (BOF) slag as secondary mineral resources. Given the composition characteristics of BOF slag, a method of synergetic modification of copper slag as additive and BOF slag was proposed to separate iron minerals for recovery. In this study, FactSage thermodynamic simulation, chemical analysis, X-ray diffraction and scanning electron microscopy were used to analyze the phase transformation and structure evolution during the oxidative modification process, and the effects of oxidation temperature and addition amount of copper slag on the modification were studied. The results show that the addition of copper slag can effectively promote the transformation of iron oxides to MgFe 2 O 4 . When an appropriate amount of copper slag was added to make the basicity of the mixed slag be 2, the conversion rate of MgFe 2 O 4 , iron recovery rate and grade of magnetic slag were the best. In the oxidative modification process, increasing the oxidation temperature was beneficial to the formation and development of MgFe 2 O 4 . However, too high temperature could lead to the dissolution of Al 3+ into MgFe 2 O 4 and reduce its magnetism, which was not conducive to magnetic separation and recovery. When the mixed slag was modified at 1200 ℃, the grade of magnetic slag by magnetic separation was 31.14 % and the recovery was 64.04 %, which had the potential of returning to sintering or ironmaking. The secondary slag obtained at the same time can also be used to produce high value-added materials. Therefore, the current technological route can transform the two kinds of industrial solid waste into usable resources at the same time, and realize "waste treatment with waste".

The Effect of Oxidation Temperature on the (1000–1300) cm−1 Band in FT-IR Spectra of Silicon Oxide Synthesized by Thermal Oxidation of Silicon Wafers

In this work, silicon wafers were thermal treated in air at temperatures varied in the range 800—1200 °C. The annealed samples were investigated using FTIR, X-ray diffraction, FTIR and optical reflection spectroscopy. The effect of annealing temperature on the (1000–1300) cm−1 band in FT-IR spectra of the prepared samples was investigated. The results showed that thermal oxidation at temperatures less than 1200 °C leads to enhance the phenomenon of the splitting of longitudinal optical and transverse optical stretching motions. This phenomenon was verified by observing the appearance of two overlapping peaks in the region (1000–1300) cm−1 in FT-IR spectra. The results also showed that the splitting process leads to the formation of defects in the crystal structure of silicon, which in turn leads to the formation of silicon nanoparticles.