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The effects of heat treatment temperature on the microstructure and mechanical properties of Cu0.3Cr2Fe2Ni3Mn2Nbx high-entropy alloys (HEAs) were studied. Results indicate that in the as-cast state, an Nb0 alloy is composed of a single FCC phase, and a Laves phase gradually forms as Nb content increases. After heat treatment at 800 °C, BCC solid solution phases rich in Cr, Fe, and Mn form in all alloys. The BCC phases in the Nb0.2 and Nb0.4 alloys decompose after heat treatment at 900 and 1000 °C, respectively, and the microhardness of the as-cast Cu0.3Cr2Fe2Ni3Mn2Nbx HEAs increases from 127 to 203 HV with increasing Nb content. After heat treatment, the microhardness of the alloys considerably improves, and the Nb0.4 alloy has the highest microhardness after heat treatment at 800 °C (approximately 346 HV). After heat treatment at 900 and 1000 °C, the microhardness of the three alloys decreases. The yield strength of the as-cast Cu0.3Cr2Fe2Ni3Mn2Nbx HEAs increases with Nb content and shows a trend of first increasing and then decreasing with increasing heat treatment temperature. The strengthening mechanism of the heat-treated alloys is mainly attributed to the second-phase strengthening of the Laves phase and the solid solution strengthening of the BCC phase. [ABSTRACT FROM AUTHOR]

ZrC whiskers were prepared on graphite through precursor transformation method. Effects of heat treatment temperature, catalyst concentration and heat treatment time on phase composition and microstructure of the ZrC whiskers were investigated. Growth mechanism of the ZrC whisker was analyzed. Results indicated that as heat treatment temperature increasing, catalyst activity increased and energy barrier for the carbothermal reduction reaction reduced, resulting in a gradual increase of both production and diameter of the ZrC whiskers. Catalyst could provide nucleation points for the ZrC whiskers, production and diameter of the ZrC whiskers firstly increased as the catalyst concentration increasing. While, when catalyst concentration was over high, length-diameter ratio of the ZrC whiskers decreased and some whiskers were agglomerated. Heat treatment time affected extent of the carbothermal reduction reaction. Production and length-diameter ratio of the ZrC whiskers increased firstly and then decreased with the increase of heat treatment time. When heat treatment temperature was 1600 °C, catalyst concentration was 0.4 mol/L, heat treatment time was 2 h, the ZrC whiskers with diameter of around 130 nm and length of tens of microns were synthesized. The whiskers were composed of a single-crystal ZrC core and an amorphous ZrO 2 shell. Growth of the ZrC whiskers was controlled by solid-liquid-solid (S-L-S) mechanism and the Ostwald ripening mechanism. [ABSTRACT FROM AUTHOR]

In order to improve the mechanical properties of SiC-MgAl2O4 composites for coal gasifiers, SiC-MgA2O4-Al composites were prepared by heat treatment in the nitrogen atmosphere using SiC particles (≼ 2.5 mm), MgAl2O4 fine powder (≼90 µm), α-Al2O3 micro-powder (d50 ≈ 5 µm) and aluminum powder (≼74 µm) as the main raw materiaIs. The effects of different heat treatment temperatures from 200 °C to 1 600 °C on the microstructure,phase composition and mechanicaI properties of the composiies were analyzed. The resuIts show that:(1) when the heat treatment temperature is higher than 1 000 °C, Al in the composites gradualIy forms Al-O-C-N whiskers,which can significant improve the mechanicaI properties of the composites;(2)the cold and hot moduIus of rupture increases with the increasing content and size of Al-O-C-N whiskers in the composites. The phase composition,content,and morphoIogy of the Al-O-C-N whiskers can be controlled by adjusting the heat treatment temperature,thereby achieving the controI of the phase composition and microstructure,and improving the mechanicaI properties of the composites. [ABSTRACT FROM AUTHOR]

In order to establish the correlation between the structure of aluminum metal and the surface properties of anodizing, the high purity Al-2% Mg flat ingots prepared by industrial semi continuous casting process were subjected to heat treatment at a temperature range of 300~550 ℃, and performed anodizing treatment with general parameters. The effects of heat treatment temperature on the metal structure and anodized surface properties (roughness, glossiness, and haze value) were studied through spectroscopy, scanning electron microscopy, optical microscopy, spectrophotometer, and haze meter. Results showed that as the heat treatment temperature increased, the surface roughness gradually decreased after anodizing, the glossiness and imaging clarity increased, and the haze value decreased. In general, these changes in surface properties were closely related to the precipitation and remelting of the second phase.

This study investigated the structural and functional changes of the interaction between preheated whey protein isolate (WPI) and anthocyanin (AN) at different temperatures through Fourier transform infrared spectroscopy, endogenous fluorescence spectroscopy, and foaming properties. The results showed that preheat treatment reduced the average particle size of the solution and increased the absolute value of ζ-potential, and the whey protein isolate after heat treatment at 70 °C had the highest binding rate to anthocyanins, which increased from 87.44 to 89.67%. Preheat treatment significantly increased the surface hydrophobicity of WPI, but anthocyanins decreased the surface hydrophobicity of the composites. Fourier transform infrared spectroscopy results indicated that preheat treatment changed the secondary structure of the WPI and WPI-AN complexes, with the α-helix content decreasing and the β-fold content increasing. The endogenous fluorescence spectra analysis illustrated the preheating treatment exposed the internal chromogenic groups of the protein and that anthocyanins increased the polarity of the microenvironment of the protein fluorescent groups and changed the conformation. The foaming properties results revealed that the combination of AN improved the foamability and foam stability of WPI, and the foaming properties of the protein was significantly improved within a certain heat treatment temperature range. In this study, preheat treatment and complexation of anthocyanins were used to improve the structural and functional properties of whey isolate protein in expectation of improving the utilization value of WPI and to provide motivation and data reference for further application of WPI in food industry. Highlights 1. The preheated WPI contributes to the formation of WPI-AN composites. 2. The addition of anthocyanins led to changes in the structure and properties of preheated WPI. 3. The combination of AN improved the foamability and foam stability of WPI, and the foaming properties of the protein was significantly improved within a certain heat treatment temperature range. [ABSTRACT FROM AUTHOR]

The present work focused on the evolution characteristics in the microstructure and properties of calcium aluminate composite ceramics after heat treatment for raw materials at different temperatures. The results showed that the apparent porosity of all the sintered samples firstly decreased to the minimum at a heat treatment temperature of 1200 °C and then increased with increasing heat treatment temperature. The compressive strength was greatly enhanced after the heat treatment for raw materials due to the significant decrease in porosity, presenting the opposite relationship with the change of porosity. The formation of the interlaced structure in the sintered samples was conducive to improving the densification of the calcium aluminate ceramics. This work provided new avenues of thought regarding the manufacturing of calcium aluminate ceramics and promoted its better application in metallurgy. [ABSTRACT FROM AUTHOR]

In this work, Mn-doped KNN (KNMN) piezoelectric ceramic coatings were prepared by plasma spraying technique, and the effects of post-treatment temperature on the microstructure and electrical properties of KNMN coatings were investigated. The results showed that the microstructure of the KNMN coating was more dense and homogeneous at the heat treatment temperature of 600 °C. The electrical properties of the coating were the best, with the dielectric constant and dielectric loss stabilized at 1580 and 0.01, and the residual polarization strength and coercivity field of the coating were 17.98 μC/cm2 and 86.78 kV/cm2, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the improvement of people's living standards, a large number of petroleum products, daily necessities and decorations that can produce volatile organic compounds are used in decoration, which seriously affects the indoor air quality. Interior decoration materials have become a research hotspot in recent years. The purpose of this paper is to develop a kind of interior wall material with good indoor formaldehyde removal effect, easily using, and low cost. In this paper, combining different heat treatment temperatures of the glaze layer, tourmaline/diatomite-based interior wall tiles were prepared by ultrafine grinding, solid sintering, and low temperature calcination. The glaze layer under different heat treatment temperatures was characterized by thermogravimetric-differential thermal analysis, X-ray diffraction, and scanning electron microscope. The influences of heat treatment temperature on the microscopic morphology and structure of the glaze layer were analyzed. Taking formaldehyde as the target degradation product, the effects of tourmaline/diatomite-based interior wall tiles on the removal of formaldehyde under different heat treatment temperatures of the glaze layer were investigated. The results showed that with the increase in heat treatment temperature, the original pores of diatomite decreased, the specific surface area decreased, and the structure of tourmaline changed. At 850°C, the surface structure of the material was slightly damaged, the strength was increased, and the removal effect of formaldehyde was better. In a 1 m3 environmental chamber, the formaldehyde removal rate reached 73.6% in 300 min. When the temperature was increased to 950°C and above, diatomite and the structure of tourmaline were destroyed, and the ability of the material to adsorb and degrade formaldehyde decreased. [ABSTRACT FROM AUTHOR]

High-capacity and affordable all-solid-state Na-ion batteries have gathered increasing interest in recent years owing to low-cost sodium, which contributes to reducing the price of these Na-ion batteries to approximately 70% of that in lithium batteries. However, in terms of electrolyte performance and battery cost, the complete replacement of lithium batteries has a long way to go. In this work, low-cost and high-safety Na 2 S·9H 2 O materials are used in synthesizing Na 3 SbS 4 solid electrolyte, the price of which is only one-fifth that of high-purity Na 2 S. The structure and electrochemical properties are studied through X-ray diffraction analysis, Raman spectroscopy, scanning electron microscopy, and electrochemical tests. Results indicate that a multiphase Na 3 SbS 4 structure containing cubic and tetragonal phases formed after heat treatment at 300 °C. In addition, a third phase transition of Na 3 SbS 4 is inferred after further heating at 600 °C. This phase structure contributes to the improvement of electrochemical performance by promoting increasing ionic conductivity to 0.54 mS cm−1 at room temperature (25 °C) and reducing activation energy to 0.076 eV. This work provides an affordable material with good electrochemical properties and not only simplifies the preparation but also greatly reduces the risk of the process. [ABSTRACT FROM AUTHOR]

The three-dimensional carbon fiber fabric was densified by chemical vapor infiltration and precursor impregnation cracking composite process, and the high thermal conductivity 3D C/C composite material with density of 1.95 g/cm3 was obtained. Using SEM, XRD, thermal conductivity test, linear expansion coefficient test and three-point bending experiment to study the effect of different heat treatment temperatures of 2350,2550,2850℃ on the microscopic morphology,structure, thermal conductivity, linear expansion coefficient and bending performance of 3D C/C composites. The results show that with the increase of the heat treatment temperature, the mesophase pitch-based carbon fiber graphite sheet structure becomes more obvious, the order of the pyrolytic carbon sheets evenly wrapped around the carbon fiber increases, and the arrangement between the sheets becomes more dense; the graphitization and thermal conductivity of 3D C/C composite materials improve; in the test temperature range of 250-1400℃, the linear expansion coefficient increases slightly with the increase of the test temperature, and the 3D C/C composite after different heat treatment temperatures. The linear expansion coefficient of the materials is -1×10-6-2×10-6℃-1, showing good "zero expansion". In addition, when the heat treatment temperature increases, the bonding of the carbon fiber and the matrix of the 3D C/C composite materials are weakened, resulting in the decrease in the bending strength and flexural modulus of the materials. A large number of long fibers are pulled out on the bending fracture surface of the materials after the high temperature heat treatment at 2850℃. In general, the fracture after three different heat treatment temperatures shows "pseudoplastic" fracture characteristics.

Pyrolysis of various fractions of crumb rubber (with particle sizes of 0–1, 1–3, 2–3.5, and 2–4 mm) obtained from the waste largesized tires was studied in the temperature range of 550–700°C and at atmospheric pressure. It is shown that in the temperature range under study, the particle size of crumb tire rubber has only an insignificant effect on the distribution of its pyrolysis products, which consist of pyrolysis gas, pyrolysis liquid, and solid carbon residue. Pyrolysis gas is a mixture of predominantly light hydrocarbons of composition C1–C4 and hydrogen, the concentration of which increases with a rise in the heat treatment temperature; pyrolysis gas can be utilized as a fuel of the high heating value (HHV), and can also serve as a raw material for hydrogen production. The pyrolysis liquid is a mixture of alicyclic, aromatic, and linear hydrocarbons of С8–С17 composition with a rather high content of value-added products, such as limonene (up to ~35.5 wt %) and cymene (up to ~14.5 wt %); after their separation, the pyrolysis liquid can be used as heating oil or as a raw material for the production of motor fuels and valuable chemical compounds. The solid carbon residue has a relatively developed mesoporous structure (with a predominant pore size in the range of ~200–400 Å) and can be used as a raw material for the production of carbon sorbents. [ABSTRACT FROM AUTHOR]

The present work looked at the effect of the heat treatment temperatures on the electrical conductivity of ZrO2-MgO-Y2O3 ceramics, and their conduction behaviors were verified by analyzing the thermal behavior and structural changes. The results indicated that the heat treatment temperatures had a deterioration effect on the electrical conductivity of ZrO2-MgO-Y2O3 (1300–1500 °C). However, the deterioration effect was gradually restrained, and the conductivity exhibited an increasing trend when the temperatures further increased to 1600 °C. The possible cause was that the samples were equivalent to be further sintered at this temperature. Meanwhile, the mean diffusion distance of Mg ions in the ZrO2 lattice during cyclic heat treatment was evaluated, strongly correlated with the phase transformation and change of electrical conductivity of the sintered ZrO2-MgO-Y2O3 electrolyte ceramics. The research findings can be used to predict the changes of electrochemical properties of ZrO2(MgO) electrolyte ceramics during high-temperature applications. [ABSTRACT FROM AUTHOR]

Copyright of Steel Pipe is the property of Steel Pipe Magazine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

FeCrMnNiCo, FeCrMnNiCo0.5 and FeCrMnNi alloys were prepared by vacuum melting and casting technology after metal powders was mixed by planetary ball mill. The effects of heat treatment temperature on the microstructures, tensile properties and hardness of three kinds of multi-principal alloys were studied by means of metallographic microscope, scanning electron microscopy (SEM), hardness tester and universal tensile testing machine. The results show that the hardness of FeCrMnNi alloy after heat treatment at 900 ℃ is the highest and the maximum hardness is 380HV. The plasticity of FeCrMnNiCo0.5 alloy is the largest after heat treatment at 700 ℃, and its elongation after fracture is 54.7%. At the same heat treatment temperature, with the increase of Co content, the alloys’ structure is changed from dendritic to honeycomb, and the alloys’ tensile strength is decreased. The hardness of the same alloy is increased with the increase of heat treatment temperature, which may be related to the increase of precipitates after heat treatment, but its tensile strength remains unchanged.

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to study the morphology of Fe-Ni alloy films and properties of coated glass at different heat treatment temperatures, the Fe-Ni alloy film is deposited on the glass substrate by vacuum electron beam heating evaporation technology. The structure of the film was analyzed by polycrystalline X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). Then the optical properties, electromagnetic properties, and electromagnetic shielding properties of the coated glass were tested. The results show that as the heat treatment temperature increases, the crystallinity of the films is better, and the body-centered cubic crystal phase gradually precipitates, which has the preferred orientation in (110) direction. Pores appear in the films when the heat treatment temperature is too high. The influence of heat treatment temperature on the haze of the coated glass is less than 1 %, but the visible light transmittance, surface sheet resistance, and relative permeability of the coated glass show a certain change with the change of heat treatment temperature. The shielding effectiveness of Fe-Ni alloy coated glass is more than 30 dB in the low-frequency electromagnetic waveband below 30 MHz, and the highest is 55 dB at 14 kHz. It is a preferred material for low-frequency electromagnetic shielding. [ABSTRACT FROM AUTHOR]

The aromatic carbon structure is a defining property of chars and is often expressed with the help of two concepts: (i) aromaticity and (ii) degree of aromatic condensation. The varying extent of these two features is assumed to largely determine the relatively high persistence of charred material in the environment and is thus of interest for, e.g., biochar characterization or carbon cycle studies. Consequently, a variety of methods has been used to assess the aromatic structure of chars, which has led to interesting insights but has complicated the comparison of data acquired with different methods. We therefore used a suite of seven methods (elemental analysis, MIR spectroscopy, NEXAFS spectroscopy, 13C NMR spectroscopy, BPCA analysis, lipid analysis and helium pycnometry) and compared 13 measurements from them using a diverse sample set of 38 laboratory chars. Our results demonstrate that most of the measurements could be categorized either into those which assess aromaticity or those which assess the degree of aromatic condensation. A variety of measurements, including relatively inexpensive and simple ones, reproducibly captured the two aromatic features in question, and data from different methods could therefore be compared. Moreover, general patterns between the two aromatic features and the pyrolysis conditions were revealed, supporting reconstruction of the highest heat treatment temperature (HTT) of char.

The aromatic carbon structure is a defining property of chars and is often expressed with the help of two concepts: (i) aromaticity and (ii) degree of aromatic condensation. The varying extent of these two features is assumed to largely determine the relatively high persistence of charred material in the environment and is thus of interest for, e.g., biochar characterization or carbon cycle studies. Consequently, a variety of methods has been used to assess the aromatic structure of chars, which has led to interesting insights but has complicated the comparison of data acquired with different methods. We therefore used a suite of seven methods (elemental analysis, MIR spectroscopy, NEXAFS spectroscopy, 13C NMR spectroscopy, BPCA analysis, lipid analysis and helium pycnometry) and compared 13 measurements from them using a diverse sample set of 38 laboratory chars. Our results demonstrate that most of the measurements could be categorized either into those which assess aromaticity or those which assess the degree of aromatic condensation. A variety of measurements, including relatively inexpensive and simple ones, reproducibly captured the two aromatic features in question, and data from different methods could therefore be compared. Moreover, general patterns between the two aromatic features and the pyrolysis conditions were revealed, supporting reconstruction of the highest heat treatment temperature (HTT) of char.

High-performance gas sensors are critical for monitoring the environment, detecting health problems and ensuring safety. Metal-organic frameworks (MOFs) are considered promising gas-sensitive materials due to their elevated porosity, large specific surface area, and various morphologies. The conversion of MOFs into metal oxides can be achieved by oxidation and roasting processes, where the structure and surface chemical composition are significantly affected by the temperature at which the roasting is performed. The structures of α-Fe 2 O 3 have been controlled by optimizing the heat treatment temperatures (350 °C, 400 °C, 450 °C and 500 °C) using MIL-100(Fe) as template which was synthesized using a hydrothermal method with reduced iron powder and 1,3,5-BTC as precursors. The gas sensitivity tests revealed that the α-Fe 2 O 3 material obtained through annealing at 400 °C exhibited excellent sensitivity to acetone，which can be attributed to the combination of its porous structure and oxygen vacancy defects. Gas-sensitive materials, synthesized using MOFs as a template with meticulous tuning of the calcination temperature, exhibit exceptional properties. These materials hold great potential for advancing sensor materials in the field of gas sensor technology. [Display omitted] • Porous α-Fe 2 O 3 materials were prepared using MIL-100(Fe) as template. • Rapid response of ppm-level Acetone at working temperature is achieved. • Under extreme humidity conditions, the α-Fe 2 O 3 materials clearly react to acetone. [ABSTRACT FROM AUTHOR]

Co-Cr-W alloy was prepared by powder metallurgy technology. The effect of heat treatment temperature on the microstructure and mechanical properties of the prepared alloy was investigated by SEM and EPMA, etc. The results show that the phases in Co-Cr-W alloy under the heat treatment condition of 1100 ℃ with holding time of 4 h and cooling without power is the same as before heat treatment. The matrix of alloy is composed of γ-Co with FCC structure, ε-Co with HCP structure, and the reinforced phases include M6C and M23C6 carbides. The matrix of Co-Cr-W alloy under the heat treatment condition of 1150-1250 ℃ × 4 h is composed of single γ-Co in FCC structure and reinforced phases include M6C carbides and M23C6 carbides. When the heat treatment temperature is increased from 1100 ℃ to 1200 ℃, the blocky M6C carbides and granular M23C6 carbides grow up, meanwhile ε-Co phases are reduced and then disappeared, alloy density is improved, and tensile strength is increased. However, when the heat treatment temperature is above 1200 ℃, the performance of Co-Cr-W alloy has no obvious change, and the prepared alloy under the heat treatment condition of 1200 ℃ × 4 h achieves the optimal property with the average hardness of 63.5HRC and tensile strength of 408 MPa.

A carbon‐coated Magnéli phase Ti4O7 composite has been successfully synthesised, via modified carbonthermal reduction of amorphous TiO2, which was prepared from hydrolysis of titanium sulphate and polyvinyl alcohol, at a relatively low temperature and fast reaction rate. Moreover, the effect of heat treatment temperature and time on the reduced phases is revealed. Despite removal of oxide ions, scanning electron microscopic images clearly show the obtained carbon‐coated Ti4O7 composite retains well the spherical morphology of the precursor, and the high‐pressure pelleted treatment effectively inhibits the growth of the final product during the heat treatment process. In addition, the prepared composite with mesopore structure exhibits a Brunauer, Emmett, and Teller (BET) surface area as high as 84.495 m2 g−1 and good electrochemical stability in alkaline electrolyte, as well as some oxygen reduction reaction catalytic activity. The results presented in this work open an avenue for its potential electrochemical applications. [ABSTRACT FROM AUTHOR]

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Porous carbon fibers (PCFs) were prepared from porous polyacrylonitrile fibers by cross‐linking, oxidation, and carbonization. X‐ray diffraction patterns revealed that graphite structures as well as disordered carbon coexisted in the PCFs. Nitrogen content was more than 15.3 wt% with the variation of oxidation temperature, and a maximum value was obtained at 275°C. Nitrogen was quickly released with carbonization temperature. Compared with the fiber prepared at elevated carbonization temperatures, those owning high nitrogen contents deserved better carbon dioxide (CO2) adsorption performance in the simulated flue gas environment (10% CO2/90% N2). The CO2 adsorption had a better relationship with nitrogen content rather than specific surface area and pore volumes. Especially, nitrogen was very useful to enhance the CO2 adsorption of the fibers with low microporosity. The heat of CO2 adsorption was in the range of 39.8–54.6 kJ mol−1, which indicated good selectivity of CO2 adsorption. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Copyright of Basic Sciences Journal of Textile Universities / Fangzhi Gaoxiao Jichu Kexue Xuebao is the property of Basic Sciences Journal of Textile Universities and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract In this work, the heating performances of electroless Ni P plated carbon fibers (MCF) at different heat treatment temperatures (300, 400, 500, and 700 °C) were investigated using an infrared thermal imaging camera. From the experimental results, we found that the MCF was a mixture of microcrystalline and amorphous phases, as indicated by XRD. In addition to the stable Ni, Ni 3 P, and NiO phases, the metastable Ni 5 P phase was also observed although the amount was small. A higher heat treatment temperature of 400 °C resulted in the growth of Ni and Ni 3 P phases indicated by the stronger peak intensity. However, the specific resistance increased as the heat treatment temperature increased above 400 °C. Accordingly, the performance of heat-treated MCF as electrical heating elements was strongly dependent on the surface structure of the MCF as well as the heat treatment temperature. The MCF exhibited a low electrical heating temperature (31.0 °C), while MCF-H400 exhibited an excellent electrical heating temperature (102.0 °C) along with rapid temperature response and high heat output to maintain a maximum temperature at a given applied voltage. Graphical abstract The MCF exhibited a low electrical heating temperature (31.0 °C), while MCF-H400 exhibited an excellent electrical heating temperature (102.0 °C) along with rapid temperature response and high heat output to maintain a maximum temperature at a given applied voltage. Image 1 Highlights • The heating performances of electroless Ni P plated carbon fibers (MCF) at different heat treatment temperatures were investigated. • The grain size of the MCF was increased with increasing the heat treatment temperature and Ni based compounds were formed in the plated. • When MCF was heat-treated at 400–500 °C, the heating performances of the MCF improved owing to the lower specific resistance, excellent electrical heating. [ABSTRACT FROM AUTHOR]

Causes of reversible changes in the coercivity of alloys for permanent magnets as a result of cyclic heat treatment are analyzed. The magnetic properties and the metallographic and magnetic domain structures of alloy Sm(Co0.65Fe0.26Cu0.07Zr0.02)7 are studied as a function of the temperature of interruption of the process cooling. The own results and data of foreign authors are used for developing a scheme of the processes occurring in the alloy in order to explain the mechanism of the "damage - restoration" phenomenon in alloys of the Sm - Co - Cu - Fe - Zr system of type Sm(Co0.65Fe0.26Cu0.07Zr0.02)7. [ABSTRACT FROM AUTHOR]

Abstract This study deals with the effects of heat treatment temperature on the thermal and mechanical properties of Na 2 O-CaO-P 2 O 5 glasses and glass-ceramics. The major crystalline phase was calcium phosphate along with sodium calcium phosphate as the minor crystalline phases presented in the glass-ceramics. Vickers hardness, Knoop hardness and Young's modulus values of the glass-ceramics decrease with increasing of heat treatment temperature, however, the opposite trend is found for the fracture toughness values. H550 sample confirms the dendritic-like structure, H600 and H650 samples confirms the lamellar bone-like structures and H700 sample confirms the scaffold-like structure. The microstructure, with cluster of dendritic crystal and lamellar structure, indicates a typical two-dimensional crystallization mechanism, which agrees with the above analysis of Avrami exponent (n = 2.8) for glass sample at T p1 while scaffold structure indicates a typical three-dimensional crystallization mechanism, which is in good agreement with the above analysis of Avrami exponent (n = 4.2) for glass sample at T p2. Moreover, all Na 2 O-CaO-P 2 O 5 bioactive glass-ceramics are not toxic to the living cell and have a good bioactive property. [ABSTRACT FROM AUTHOR]

Abstract First of all, the temperature dependence of the electrical resistivity of the single-crystalline graphite was analyzed by combining the simple two-band (STB) model of the π-electron band structure of graphite with the proper scattering law. Then, the regression equations for the change of resistant characteristic factors (that is, crystallite size, average kinetic momentum of carriers, correction coefficient of resistivity, energy band gap and so on) according to the heat treatment temperature of graphitizing carbon materials, were estimated analytically on the basis of the preceding literature and their physical consideration. By introducing the above regression equations for the resistant characteristic factors into the analytic expression for the electrical resistivity of single-crystalline graphite, the universal formula to calculate numerically the temperature dependence of the electrical resistivity with heat treatment temperature of the graphitizing carbon materials, was obtained. So, the correctness of the numerically-calculated results based on this theoretical formula was proved by contrasting them with the preceding experimental results. As a result, the temperature dependence of the electrical resistivity with heat treatment temperature of the graphitizing carbon materials can be estimated easily by the method of computational physics rather than in the experimental way. Highlights • Temperature dependence of resistivity of single-crystalline graphite physically was analysed. • On the basis of this analysis, temperature dependence of resistivity with heat treatment temperature of graphitizing carbon materials was quantified. • For quantitative analysis, regression equations for change of resistant characteristic parameters with heat treatment temperature were determined. • Characteristic points of graphitizing carbon materials can be analytically estimated with heat treatment temperature. • In contrast, it is possible to determine the heat treatment temperature and crystallite size corresponding to any characteristic temperature. • Analytically-calculated results were compared with experiment one and correctness was proved. [ABSTRACT FROM AUTHOR]

Phosphorus (P) in biochar serves as both a P source for plant growth and a contributor to water eutrophication, thus prioritizing the efficient management of P in biochar. This study employed solid- and solution- state 31 P-nuclear magnetic resonance and X-ray diffraction analyses to explore the impact of feedstock and heating treatment temperature (HTT) on P species of biochars. The effects of ambient temperature, coexisting anions, pH and nutrient solution on P release were also investigated to study the effect of various environmental factors on P release from biochars. P species in both plant- and manure- derived biochars were dominated by inorganic orthophosphate and pyrophosphate (mainly calcium-bound-phosphates). The HTT of biochar showed a negative impact upon its pyrophosphate content. Compared with plant biochars, manure biochars contained higher P but had a lower release degree. Release of P from biochars was controlled by diffusion-dissolution process and was enhanced by higher ambient temperature, co-existing anions, and both acidic and alkaline conditions but inhibited by coexisting Hoagland nutrients. Anion-induced increase in P release was more significant for plant biochars than manure biochars. These findings help to adjust favorable environmental conditions for the full utilization of P in biochars. [ABSTRACT FROM AUTHOR]

In this paper, (CoFe2O4–Pb (Zr0.52Ti0.48)O3)n [(CFO-PZT)n]composite films, which belongs to 2-2 type multi-layer and have good ferroelectric ferromagnetism, were prepared by the tape casting method. The surface morphology, ferromagnetism and ferroelectric properties of (CFO-PZT)n composite films were characterized by X-ray diffractometer, scanning electron microscopy, vibrating sample magnetometer and TFAnalyzer 2000 UL ferroelectric tester. The results show that PZT with the perovskite structure and CFO with the spinel structure are uniformly distributed in the multi-layer composite films, and the interface is even and uniform. With the increasing in annealing temperature, the density of the films increases and the grains grow up, but the phase structure does not change and no new phase is formed. The remanent polarization of (CFO-PZT)n composite films annealed at 900 °C is 32.63μC/cm2 and the saturation magnetization is up to 80.56 emu/cm2. saturation magnetization is as high as 80.56 kA/m and the magnetoelectric coupling coefficient is 17.69 mV/(cm • T) at 2.29×104 A/m bias magnetic field. [ABSTRACT FROM AUTHOR]

A quaternary bioactive sol-gel glass of high silica content was heat treated at different temperatures, and then wet ball milled under different balls-to-powder ratios. A total of sixteen experiments were performed to study in detail the effects of both experimental variables on the structure, morphology, particle size distributions and nitrogen adsorption isotherms. The balls–to–powder ratio exerts a tremendous influence on the final particle size distribution of the powders, while its effects on the pore volume and morphology are minimal. These structural features are mostly governed by the changes in calcination temperature. Therefore, understanding the specific roles of each experimental parameter is of paramount importance towards achieving optimum powders with the desired properties. This work sheds light on the importance of using a suitable combination of these two parameters for tuning the morphology and the granulometry of the sol-gel derived bioactive glass powders. [ABSTRACT FROM AUTHOR]

In this paper, the relationship between the heat treatment temperature and the thermomechanical behavior of the Ni-rich NiTi shape memory alloy was experimentally investigated. Thermal analysis was performed through a differential scanning calorimetry experiments, and the NiTi superelastic effect was exhibited through loading/unloading compression cycle. It was found that the transformation temperatures and the compressive mechanical response are strongly affected by the heat treatment temperatures. The stress-induced phase transformation was characterized through the relationship between the heat treatment temperature and transformation stresses, elastic moduli and the deformation level upon loading. Subsequently, the evolution of the mechanical hysteresis loops and the mechanical dissipated energy was discussed. The obtained findings are supported by hardness measurements. To better understand the global tendency of the various phase transformation stages, the critical stress-temperature diagram was provided for different proposed heat treatment temperatures. [ABSTRACT FROM AUTHOR]

TiO films were coated on the surface of diamond particles using a sol-gel method. The effects of heat treatment temperature on the morphology, phase composition and chemical bond of diamond particles coated with TiO films were investigated through SEM, TEM, X-ray diffraction analysis, Raman spectroscopy, FTIR, and XPS. The results showed that when being heat-treated at 600 °C, the amorphous TiO film transfered to the anatase film which bonded well with diamond substrate. Meanwhile, the Ti-O-C bond formed between TiO film and diamond substrate. When being heat-treated at 800 °C, TiO film was still anatase, and partial diamond began to graphitize. The graphitizated carbon could also form the Ti-O-C bond with TiO film, although TiO film would tend to crack in this case. [ABSTRACT FROM AUTHOR]

Organic-inorganic hybrid perovskite materials exhibit excellent photoelectric properties. Their photoelectric performance strongly depends on the film morphology and size, controlled by the deposition technique and subsequent heat treatment. In this article, perovskite film was deposited by the drop casting method in contrast to the widely used techniques such as spin-coating. The perovskite solution precursor was obtained by adding PbI 2 and CH 3 NH 3 I (1:1 molar ratio) into the N,N-dimethylformamide (DMF) solvent until they were dissolved. Fluorescent properties of the perovskite solution precursor were analyzed. Two emission bands were observed at 1.5 eV and 2.5 eV. Drop the solution precursor on the substrate, evaporate the solvent, the grain size distribution present larger on the edge of the substrate than the center. The grain size distribution presented a ring shape distribution, and the mechanism of grain growth was discussed. During the solvent evaporation, formed compensating flow from the solution center to the edge. The concentration of solution edge is higher, so it promotes the grain growth. The effect of heat treatment temperature on the film morphology, structure and composition was studied. It was found that the grains with millimeter-scale were obtained when the heat treatment temperature changed from 70 °C to 115 °C. Furthermore, increasing the heat treatment temperature above a certain threshold lead to the additional formation of PbI 2 . [ABSTRACT FROM AUTHOR]

In this study, hypoeutectic high chromium cast iron (HCCI) is deposited on low alloy steel by using electroslag welding. The yielded mixture is furthered introspected by exposing it to range of temperatures (i.e. 440 °C, 480 °C, 520 °C, 560 °C, 600 °C). The respective microstructures are studied after the heat treatment, subsequently. Additionally, microstructures are also examined in terms of their hardness and wear resistance. The results demonstrate that hardness, wear resistance and coefficient of friction (COF) are correlated and these attributes reaches to their maximum value when the mixture is found to be composed of secondary carbides and martensite. It is evaluated that, when the HCCI hardfacing layer is post weld heat treated (PWHT) at 520 °C then the secondary carbides (M 23 C 6 ) and martensite quantities are quantified as maximum and by comparing it with HCCI hardfacing layer, hardness, COF and wear resistance are found to be increased by 11.88%,25% and 30%, respectively. Wear resistance is also found to be at the maximum value at PWHT 520 °C holding crack at maximum depth of 2 μm. These findings reveal that HCCI hardfacing layer with PWHT temperature 520 °C can achieve the best outcome. [ABSTRACT FROM AUTHOR]

Nanosized biochar (NBC) is an important fraction of biochar (BC) as it can exert nano-scale effects on aquatic organisms, attracting increasing research attention. However, effects of different physicochemical properties of NBC on biological responses at the metabolic and gene expression level are not comprehensively understood. Here, biological effects of NBCs pyrolyzed at different heat treatment temperatures (HTTs, 350–700 °C) were evaluated using freshwater algae Chlorella vulgaris , from the perspectives of growth and fatty acid (FA) profile changes. NBC pyrolyzed at 700 °C (N700) induced the greatest algal growth inhibition and oxidative stress than N350 and N500. In addition, NBC exposure to 50 mg/L increased saturated and monounsaturated FAs, along with a decrease in polyunsaturated FAs (PUFAs). Exposure to NBC also significantly influenced the expression of key FA metabolism genes (3fad, sad, kasi and accd), demonstrating the potential role of reactive oxygen species-mediated PUFA reduction accompanied by increased membrane permeability in algal toxicity upon NBC exposure. The observed differences in response to N700 were attributed to its smaller particle size and higher abundance of –COOH. These findings reveal the underlying mechanisms in the algal response to NBCs and provide valuable guidance for the safe design and application of BC materials. [Display omitted] • Effects of NBCs pyrolyzed under different HTTs on algae were investigated. • N700 exhibited stronger growth inhibition to algae than N500 and N350. • Temperature-dependent toxicity was due to NBC's particle size and abundance of –COOH. • Oxidative stress and FA metabolism homeostasis disruption were induced by NBCs. • NBC exposure influenced the expression of four key FA metabolism genes. [ABSTRACT FROM AUTHOR]