Effect Of Heating Temperature Research Articles

Reversible Photobleaching of Silver Clusters in Silica‐Based Glass under Ultraviolet Irradiation

AbstractInorganic glasses doped with luminescent silver clusters are promising materials for photonic applications as white light generation, optical data storage, and spectral conversion. This work reports the photostability study of luminescent silver clusters dispersed in silica‐based glass under continuous ultraviolet irradiation. The photobleaching process model is proposed and the quantum yield of photobleaching is derived from the experimental data. The proposed mechanism of photobleaching is photoionization of silver clusters. Degradation of cluster luminescence is reversible and restores after the heat treatment, indicating the possibility to release trapped electrons and return the initial charge state of clusters. The effect of heat treatment temperature on the luminescence restoration is studied, the amount of restored luminescent clusters depends linearly on the heat treatment temperature.

Sn3Sb2S6 thin films for photovoltaic applications

Tin antimony sulfide semiconductor thin films have been extensively investigated due to their potential application as absorber in thin films solar cells, to convert solar radiation into electricity (A. Gassoumi, 2011; A. Larbi, 2014; Auttasit Tubtimtae, 2021; D. Abdelkader, 2014; N. Ali, 2015; Nisar Ali S. H., 2013a; Nisar Ali S. H., 2013b; Sebin Devasia, 2020); this is due to the excellent optoelectronic properties and due to abundance of the constituent elements on the earth crust and low toxicity. In this research we studied the effect of heat treatment temperature on the formation and optoelectronic properties of Sn3Sb2S6 thin films prepared by the heating of multilayers glass/ SnS/Sb2S3 chemically deposited, the results show the formation of the ternary phase at temperatures above 250 °C, increasing the crystallinity of the phase at 325 °C. Sn3Sb2S6 thin films show an indirect optical transition with band gaps around 1 eV, and absorption coefficient  105 cm-1 in the visible range. Sn3Sb2S6 thin films show conductivities in the range of 10-7 – 10-6 Wcm-1 , showing an increase in conductivity as the temperature increased. The good optoelectronic properties of this material make it suitable for photovoltaic applications.

Preparation of a modified multi-component phosphate adhesive for connection of 316L stainless steel and its reinforcement mechanism

In this paper, a novel phosphate-based adhesive with excellent high-temperature bonding strength was prepared by using phosphate as the matrix and modified B4C, modified TiO2 as well as low-temperature fused Zn–B–Si–Al-R glass materials as fillers. The effects of heat treatment temperature and filler compositions on the high-temperature bonding strength of the adhesive were investigated. The results indicated that the aluminum phosphate in the adhesive was transformed from orthorhombic to cubic crystalline at 210 ± 5 °C, which increased the cell stacking density from 2.19 g/cm3 to 2.74 g/cm3 and made the binder dense. After calcination at 500 °C, a large number of pyrophosphates were generated inside the adhesive, and the chemical bonds such as P–O–Si and P–O–Cu in these pyrophosphates formed reticulated skeletal macromolecules, which improved the network structure of the transition zone between the adhesive and stainless steel. Meanwhile, the difference in potential resulted in the exchange of Fe and Cu2+, H+ at the bonding interface to enhance the high-temperature resistance and bonding strength of the specimen. When the additions of La2O3, Fe2O3, ZrO2, CuO were1.2%, 5%, 10%, and 15%, the maximum tensile strength of the specimen reached 8.73 MPa at 500 °C. The phosphate binder prepared in this work could be widely used in the field of high-temperature material repair such as aerospace and energy.

Effect of heat-treatment temperature on the structure of calcium phosphate synthesized by wet precipitation

In this work, nanometric calcium phosphate (CaP) was synthesized by wet chemical precipitation using Ca(OH)2 and H3(PO4). The subsequent heat treatment was carried out varying from 25 °C to 1000 °C, to study the changes caused in the structure of the final product through XRD, FTIR, Fluorescence, Raman, UV–Vis, DLS, Zeta Potential, SEM and TEM/EDS analyses. Cell viability was measured via MTS assays. XRD showed that the crystallinity of the synthetic calcium phosphate obtained increases with increasing heat-treatment temperature, getting close to the structure of hydroxyapatite. In the FTIR, Raman and UV–vis spectroscopic analyses, carbonate removal from the synthesized CaP structure at high heat-treatment temperatures was observed. Samples T800 and T1000 showed greater fluorescence. DLS measurements revealed the formation of aggregates at heat-treatment temperatures lower than 800 °C. According to the Zeta Potential measurements, T1000 is the most stable colloid (−28.4 ± 1.4 mV). The thermal treatment also affected the morphology of the samples, and nanowhiskers, nanorods and nanocubes were observed. In addition, the viability assay revealed that a decrease in particle sizes in CaP samples led to a decrease in metabolic activity, showing that the correct choice of particle size is the key to producing compounds that favor cell proliferation, making it a promising material for bone tissue engineering.

A physically-based model for elevated temperature strength prediction of (TiBw + (Ti, Zr)5Si3)/Ti-6.5Al-2Zr-1Mo-1V composite

In this paper, effects of heat treatment temperature and soaking time on the microstructure and elevated temperature mechanical properties of the (TiBw+(Ti, Zr)5Si3)/Ti-6.5Al-2Zr-1Mo-1V composite were studied. A physically-based model capable of predicting microstructure and yield strength was established. Results show that acicular martensite forms in the transformed β microstructure, the size of (Ti, Zr)5Si3 increases obviously, while the morphology of TiBw remain unchanged. With the increase of heat treatment temperature, the fraction of primary α phase and (Ti, Zr)5Si3 decreases, while the fraction of βT increases. The yield strength and ultimate tensile strength of the composite are improved by 34% and 46% after heat treatment at 975 °C. The yield strength can be accurately predicted by the model. The mean relative error (MRE) of yield strength calculated by the model was 1.20% under the condition of heat treatment at 900 °C and 1050 °C. Using the model, martensitic strengthening accounts for the largest proportion in yield strength. The variation tendency of yield strength with temperature is predominantly decided by the variation tendency of martensitic strengthening. And the heat treatment temperature affects the yield strength through the factors including the fraction of βT and the lamellae thickness of martensite.

Effect of heat treatment temperature and atmosphere on physiochemical properties and oxidation behaviour of a Chinese lignite

Effect of heat treatment temperature and atmosphere on physiochemical properties and oxidation behaviour of a Chinese lignite

Synthesis and investigation of the physicochemical properties of polymorphic 3C–SiC

Silicon carbide (SiC) nanopowders were synthesized under Ar atmosphere via the carbonization reaction method using silicon powders and expanded graphite as initial materials, and ferric nitrate as catalyst precursor. The effects of heat treatment temperature and the C/Si molar ratio on SiC products were studied. The microstructure, phase composition and chemical state of the products were analyzed by XRD, SEM, XPS, TEM and Raman. The photoluminescence (PL) properties of SiC nanopowders were tested. The results showed that the content of the 3C–SiC product is higher after heat treatment at 1400 °C for 3 h with a molar ratio of C/Si of 1:1. 3C–SiC exists in the form of particles and wires. The formation process of 3C–SiC can be explained by a two-step method, nucleation under catalysis and growth under Vapor-Solid (VS) mechanism. Two ultraviolet light emission peaks are observed at about 318 and 380 nm. The main PL spectra of 3C–SiC nanopowders exhibit larger blueshifts. The blueshift is attributed to the stacking fault, oxygen defects, morphology and quantum confinement effect. It has potential application prospects in ultraviolet detectors, optoelectronic devices and light emitters.

Effects of heat treatment on microstructure and properties of Fe-based amorphous composite coatings

It is found that heat treatment can improve the microstructure and properties of the coating. In this paper, the Fe-Cr-Mo-B-C amorphous composite coatings fabricated by laser cladding technology were heat treated at different temperatures. The effects of heat treatment temperature on the crystallisation, porosity, microhardness, and corrosion resistance of coatings were investigated. The experimental results show that the amorphous content and porosity after heat treatment, the comprehensive properties are improved, and the coating defects are solved. Both the amorphous content and the porosity affect the corrosion resistance of the coatings. The smaller the porosity, the higher the amorphous content, and the stronger the corrosion resistance of the coating. When the difference in amorphous content is small, the porosity of the coating becomes the dominant factor affecting the corrosion resistance of the coating. The experimental results shows that the best optimum heat treatment temperature for the coatings is 200°C.

Effect of temperature on the internal components including portlandite, weight loss, and compression stress-strain behavior of lime-based roof and screed paste

Conventional lime-based roof and screed pastes (LRP) are multilayer complicated systems composed of various ingredients and binders; their physical properties define the function of LRPs: interact connection, underlayer contact, and external variables. Lime pastes sets as a durable and generally flexible solid mass. It is breathable and permits the transfer and evaporation of moisture. Pastes made of hydrated lime are less brittle and breakable. Hence expansion joints are unnecessary. Various pastes, including cement, lime, mud, stucco, and gypsum, have been used in the building industry. Traditionally, lime pastes often included horse hair for reinforcing and pozzolanic ingredients to decrease application time. As building insulation materials (Bims), a lime-based paste is used against environmental concerns. Microstructure tests, thermal analysis, and compressive strength was used to identify, characterize, and evaluate the LRP. The thermogravimetric analysis (TGA) findings demonstrated that the material exhibited high thermal stability up to 200 °C and 11.4% weight loss at 975 °C, demonstrating the high heat resistance of the LRP. At 28 days of curing, the compressive strength of the LRP with water binder ratio (w/b) of 0.75 and 0.60 was 718.76 and 1190.58 kPa, respectively. Heat treatment at three temperatures of 40, 60, and 80° Celsius for 7 h was applied to the samples immediately after demolding. The compressive strength of all the samples, especially the samples with w/b = 0.60, in 3 days increased significantly when the temperature increased. However, this change was less than 28 days of curing time. The final effect of heat treatment temperatures (40, 60, and 80 °C) on 28-day samples with w/b = 0.60 was 116, 106, and 109%, respectively. The maximum quantity of Portlandite that improved the compressive strength of LRP occurred at 40 °C. The analysis of)SEM(images and observing the percentage of Portlandite development at the fracture surface of the samples also confirmed the order of the above changes.

Effect of heat treatment temperature on preparation and characterization of CuInSe2 thin films

Effect of heat treatment temperature on preparation and characterization of CuInSe2 thin films

Effect of Heat Treatment Temperature on Structural and Electrical Properties of Plasma Sprayed KNMN Coatings

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.

Effects of heat treatment temperature on the morphology, composition, and electrocatalytic properties of electrodeposited NiB thin films towards OER

In this study, we evaluate the textural properties, elemental composition, and electrocatalytic properties of NiB films formed by electrodeposition and thermal treatment at 520 and 650°C. The NiB films were characterized by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), atomic force microscopy (AFM), glow discharge optical emission spectroscopy (GD-OES), X-ray diffraction (XRD) and X-Ray photoelectron spectroscopy (XPS). The morphology and composition of the NiB films were affected by the applied thermal treatment, showing an increase and decrease in oxygen and boron concentrations in the coatings, respectively. This behavior is associated with the decomposition of the NiB intermetallic compounds, as well as the formation of NiO with increasing temperature. In addition, the XPS analysis showed that the percentage of surface defects formed during the electrodeposition of the NiB films decreased after the thermal treatment of the samples. Linear voltammetry, chronoamperometry, and electrochemical impedance spectroscopy (EIS) were used to evaluate the electrocatalytic activity of the NiB films towards the oxygen evolution reaction (OER). NiB films without thermal treatment showed the lowest onset potential for the OER (1.47 V vs. RHE), overpotential to reach 10 mAcm−2 (400 mV), Tafel slope (68 mV dec−1), and charge transfer resistance (2.4 Ω). This finding reveals that the NiB electrocatalyst without thermal treatment presents similar or superior performance to other electrocatalysts reported in the literature, while the OER kinetics of the NiB electrocatalyst decreases after heat treating at 520 or 650°C, due to the NiB decomposition, decrease in the percentage of surface defects and NiO formation.

Preparation and characterization of fiber braided tube reinforced polyethylene hollow fiber membranes via thermally induced phase separation

In wastewater treatment applications, mechanical strength of the membranes often cannot meet practical requirements due to the disturbance of aeration flow or the damage of high-pressure cleaning. In this work, fiber braided tube reinforced polyethylene (BR PE) hollow fiber membranes with desirable filtration performance and high tensile strength were successfully prepared via fiber braided tube reinforcement (BR) and thermally induced phase separation (TIPS) methods. Especially, the effect of heat treatment temperature on structure and properties of the membranes was discussed. The results exhibited that tensile strength and interfacial bonding state between the surface separation layer and the fiber braided tube reinforcement were improved with the increase of heat treatment temperature. While the heat treatment temperature was 130 °C, BR PE hollow fiber membranes exhibited favorable interfacial bonding state, and tensile strength was up to 204.4 MPa, which was significantly higher than that of previously reported PE membranes. Moreover, the increase of heat treatment temperature could decrease the membrane pore size and improve filtration performance. Comprehensive consideration, the optimal heat treatment temperature of BR PE hollow fiber membranes was 110 °C. This work can provide scientific and practical basis for large-scale development of BR hollow fiber membranes with good comprehensive performance.

Effect of heat treatment temperature on the microstructure and microhardness of TiC/Ti6Al4V composite manufactured with laser metal deposition

This study presented the investigation of the influence of post heat treatment temperature on the microstructure and hardness of TiC/Ti6Al4V composite manufactured with laser metal deposition. Heat treatment was performed to improve the microstructural homogeneity. It was found that the addition of TiC into Ti6Al4V results in the formation of a Widmanstätten microstructure with different grain sizes on the matrix. Heat treatment of the TiC/Ti6Al4V promoted phase transformations from acicular in the as built to lamella (α + β) and equiaxial phases in the heat-treated samples. The 900°C heat treated sample showed a uniform distribution of α and β phases, and 1100°C showed an increase in β phases, which resulted in an equiaxial microstructure. Moreover, Heat treatment at 1100°C resulted in the highest microhardness of 665±13HV.

Weibull Reliability and Mechanical Properties of Chemical Strengthening Lightweight Glass Containers Using Spray Coating

In this study, the effects of heat-treatment temperature and hot-end coating (HEC) by spray coating on the mechanical properties and reliability of lightweight glass bottles were investigated. When the chemical strengthening occurred at Tg, the hardness and impact strength increased by 163% and 198%, respectively. All specimens exhibited improved mechanical properties with chemical strengthening, regardless of the HEC. The strengthening effect was relatively large in the absence of HEC. However, the distribution of the impact strength was smaller when HEC was applied. Compared to non-HEC bottles, HEC glass bottles had higher Weibull modulus values after chemical strengthening, which increased their reliability. Therefore, it is possible to chemically strengthen a lightweight glass bottle by spray-coating. Chemically strengthened lightweight glass bottles with excellent mechanical properties and high reliability can be produced when both HEC and chemical strengthening are applied.

Fabrication, characterization and application of single-phase hollow BiFeO3 nanofibers as an efficient visible-light photocatalyst for degradation of Rhodamine B in wastewater

In this paper, we conducted a study on the structural modulation and photocatalytic performance of single-phase hollow BiFeO3 nanofibers (SPH–BFO NFs) photocatalysts, investigated the effect of heat treatment temperature on the structure of BFO NFs and the formation mechanism of a hollow structure. The SPH-BFO NFs consist of BiFeO3 nanocrystals without other heterogeneous phases, with diameters of 400–600 ​nm and extraordinary flexibility, allowing easy separation of the catalyst from the solution. As a result, the SPH-BFO NFs possess outstanding photocatalytic performance and higher photocatalytic efficiency compared with other forms of BiFeO3. In addition, the effects of different environments and water quality on RhB degradation were investigated. It was found that the vacancies (h+) and superoxide radicals (·O2−) as active substances were less environment-dependent, making the SPH-BFO NFs more resistant to environmental interference. The RhB degradation efficiency of BFO NFs was about 99% in 10 ​mg/L of RhB dye solution at pH ​= ​6. This work provides valuable insights into the application of SPH-BFO NFs in photocatalysis and the design of nanofiber photocatalysts.

Effect of post-weld heat treatment on the microstructure and mechanical properties of laser-welded joints of SLM-316 L/rolled-316 L

Abstract Connecting small pieces of parts manufactured by Selective Laser Melting (SLM) and traditional formed parts into large structural component by using welding technology provides a high-efficiency and low-cost way for expanding additive manufacturing technology. SLMed parts usually exhibit similar or superior tensile strength but lower ductility compared to that of cast or rolled ones due to the rapid cooling and cyclic heating deposition characteristics. What about the weldability of the dissimilar joints of SLMed parts and rolled ones? Whether the properties of the welded joints can be improved by heat treatment under the premise of ensuring the reliability of the joint is unclear. The weldability and the effect of heat treatment temperature on the microstructure and properties of laser-welded joints of SLM-316 L/rolled-316 L are studied in this article. The results show that the joints exhibit good weldability without obvious defects. The low temperature annealing treatment had no significant effect on the multilayered structure and columnar austenite grains, but only changed the morphology and content of ferrite within the grains leading to the slight increase of elongation but decrease of material strength. The corrosion performance was almost unaffected. After solution annealing above 1,000°C, the ferrite was nearly dissolved in the austenite matrix. The austenite recrystallized and the multilayered structure was destroyed, which resulted in decrease of material strength, a slightly improvement in corrosion resistance, and the elongation was greatly enhanced. After the detailed study, it was concluded that the post-weld heat treatment provided an effective way for improving the overall performance of the SLM-316 L/rolled-316 L dissimilar joint.

Effect of heat treatment on structure and mechanical properties of basalt fibers and its application for fabrication Cu based composite

This paper firstly presents an experimental investigation of the effects of heat treatment temperatures and atmosphere on the tensile strength and structure of basalt fibers. The results show that the basalt fibers after heat treatment in air (200–600 °C) have the characteristics of amorphous state due to the oxidation of Fe2+ into Fe3+. On the contrary, the vacuum heat treatment induces the crystallization of basalt fibers. The reason is that the Fe2+ cations can act as network modifiers and the Fe3+ can participate in and enhance glass network. Furthermore, the single fiber strength of basalt fiber decreases with the increase of heat treatment temperature. However, the single fiber strength of basalt fibers after vacuum heat treatment is about 3 times that of basalt fibers after air heat treatment. On this foundation, basalt fibers were used for fabrication of copper matrix composites by spark plasma sintering (SPS) and hot press sintering (HPS) for the first time. The results exhibit that the strength of basalt fibers reinforced copper matrix composites prepared by SPS is 276 MPa, which are higher than that by HPS (192 MPa) due to fast heating rate and short holding time.

The effects of heat treatment temperatures on photocatalytic activity of cobalt ferrite nanoparticles synthesised by microwave‐assisted combustion method

AbstractIn this study, the effects on the photocatalytic activities of particles after heat treatment has been applied to cobalt ferrite nanoparticles produced by microwave‐assisted combustion method were observed. The heat treatment applied to the samples was produced with only the microwave effect, at temperatures ranging from 300 to 1000°C. Thermogravimetric analysis was performed on the precursor sample in air atmosphere. During this analysis, the gases released up to 1200°C were identified with a Fourier‐transform infrared (FTIR) spectrometer integrated into a thermogravimetric analysis system. Then, the cobalt ferrite nanoparticles produced with heat treatments applied at various temperatures were used as a photocatalyst to remove the dyestuff content in synthetic wastewaters prepared by using Astrazon Red GTL textile dye by photocatalytic oxidation, and their photocatalytic activities were compared. In these experiments, the operational parameters for photocatalysis processes were applied as 400 rpm for stirring speed, 50 mg/L for initial contaminant concentration, 0.5 g/L for catalyst dosage, 25°C for temperature, and 4400 μW/cm2 for light intensity. As a result of the experiments, it was observed that the crystal structure of the cobalt ferrite nanoparticles produced with the increase of the applied heat treatment temperature improved significantly. The obtained data show a strong relationship between the structural properties of materials and their photocatalytic activities. In addition, it was determined that the dyestuff in the solution was completely degraded in the experiments, and it was determined that all processes were compatible with the pseudo‐first‐order kinetic model.

Highly efficient RuTe2/C electrocatalyst for oxygen reduction reaction in proton exchange membrane fuel cells

It is desirable but challenging for ruthenium (Ru)-based chalcogenides to achieve high activity and good durability toward oxygen reduction reaction (ORR) in fuel cell applications. In this work, a facile microwave route followed by heat treatment was utilized to synthesize carbon supported ruthenium tellurium (RuTe2/C) catalysts, and the effects of heat treatment temperature on crystal structure, microstructure, chemical state, electrocatalytic activity, and fuel cell performance were studied. The mixed phase of predominant orthorhombic RuTe2 and minor hexagonal Ru was identified as dual active sites for RuTe2/C catalysts. Density functional theory calculations demonstrated that orthorhombic RuTe2 exhibits enhanced intrinsic activity relative to pure Ru due to the weakened absorption energies of oxygen intermediates. Because of the smallest nanoparticle size and complete formation of an orthorhombic RuTe2 structure, the best ORR performance was achieved with the RuTe2/C catalyst heat treated at 400 °C, showing a maximum half-wave potential of 0.70 V and only a 70 mV drop (10.0% loss) after 6000 potential cycles. In a H2/O2 fuel cell test, the best-performed RuTe2/C catalyst delivered a maximum power density of 672 mW⋅cm−2 using a low cathode Ru loading of 0.18 mg·cm−2, which is the best performance ever achieved for the Ru-based catalysts. After 6000 cycles of rigorous accelerated degradation test, the cell performance decayed by 55.4% because of the migrations of Te and Ru from the cathode side to the anode side and the growth of the RuTe2/C nanoparticles.