Preheat Temperature Research Articles

Crack-free hard facing options for orifice plate used in oil refinery applications

The purpose of this study is to select a suitable tubular wire electrode as an alternative hardfacing material for Stellite 1 in the production of SS304 orifice plates used in oil refineries. It is also intended to develop an efficient deposition procedure for crack-free hardfacing. Compatible cobalt, nickel, and iron-based hardfacing alloys were selected so as to match the hardness and hot hardness properties of stellite 1. Moving heat source analysis was performed to find the heat affected zones and the thermal stress distribution during hardfacing. The significance of weld speed, bead width, and weld concentration on the weld deposition process was analysed using ANSYS, to extract an efficient deposition procedure. The hardfacing alloys were tested for stress and deformation at working temperature (up to 815 οC) to understand the performance. Seven materials were taken into consideration as options along with six parameters. The results revealed a higher longitudinal residual stress of 2000 MPa for Talonite and Tribaloy hardfacing alloys. Colmonoy 6 was found to be having the least stress value of 2186 MPa. Furthermore, the von mises stress values arrived for different conditions showed that the optimal welding condition is 5 mm/s welding speed, 3 mm radius of beam and 455 °C preheat temperature. Microstructural study revealed the dendrite growth in the surface of Colomony 6 hardfacing during solidification, which led to the improvement in mechanical properties.

Study on the Optimization of Investment Casting Process of Exhaust Elbow for High-Power Engine

The high-power engine exhaust elbow has a complex construction, which makes it susceptible to casting flaws that could negatively impact its functionality. Therefore, the investment casting scheme was established and optimized in this study in order to cast structurally complete exhaust elbows for high-horsepower engines. ProCAST software was used to simulate and optimize the casting and solidification processes. The optimal process parameters were determined as follows: pouring temperature of 1650 °C, pouring speed of 1.5 kg/s, and shell preheating temperature of 1050 °C. The optimization of the primary parameters of the casting process, along with the results of dimensional accuracy analysis, shape and positional deviation, and defect detection, were validated through testing. The results indicated that the optimized castings had no casting defects and complied with the design specifications.

Optimal Preheating Boosts Aluminium Weld Strength

Based on the conducted research, it is concluded that preheating has a significant impact on the tensile strength of welded aluminium 5083. Specifically, preheating at 40°C resulted in the highest ultimate tensile strength of 304.535 MPa, representing an 8.748% increase compared to the non-preheated specimen's 301.894 MPa. Conversely, preheating at 80°C led to a notable decline in tensile strength to 253.521 MPa, a decrease of 16.023%. These findings imply that moderate preheating can enhance the weld quality of aluminium 5083, while excessive preheating adversely affects it. This underscores the importance of optimizing preheating temperatures in welding processes to achieve desired mechanical properties. Further research is recommended to explore the underlying mechanisms affecting tensile strength at various preheating temperatures and to investigate the effects of preheating on other aluminium alloys. Highlight: Preheating at 40°C improves tensile strength by 8.748%. Excessive preheating at 80°C decreases tensile strength by 16.023%. Optimal preheating temperature crucial for weld quality in aluminium 5083. Keywoard: Aluminium 5083, Preheating, Tensile Strength, Welding, SMAW

Effect of forging routes on the microstructure and mechanical properties of newly-developed Ti-44Al-5.5Nb-0.5W-0.5Cr-0.3Si-0.1C alloys

In this study, the effects of forging routes on the microstructure and tensile properties of Ti-44Al-5.5 Nb-0.5 W-0.5Cr-0.3Si-0.1 C (at%) alloys was comparatively investigated. Results showed that the bare ingot forged at 1400 ℃ (BH) exhibited refined lamellar colonies with narrow lamellar spacing. In contrast, dynamic recrystallized γ grains and lamellar structure with thick lamellar spacing formed in the canned sample deformed at 1320 ℃ (CA). In addition, the heat-treated BH-HT sample showed fully recrystallized texture, while the lamellar structure in the CA-HT presented a preferred orientation, i.e., lamellar interfaces were parallel to rolling direction (RD). The mechanical properties of the CA-HT sample test results showed superior room-temperature ductility of 1.68 % and tensile strength of 515 MPa at 950 ℃ due to the lamellar orientation alignment to tensile direction. According to the temperature drop calculation results, both BH and CA forging routes exhibited rapid cooling rates. The initial microstructure at the pre-heating temperature was maintained until a hot deformation sequence was initiated. Therefore, the BH route could be performed in the α+β region, while the CA route could be carried out in the α-forging condition with the 1101̅12 γ texture.

Studies on the effects of preheated β-lactoglobulin on the physicochemical properties of theaflavin-3,3′-digallate and the interaction mechanism

Teaflavin-3,3′-digallate (TFDG) is a sensory and health benefit substance in tea beverage, but is usually eliminated during processing due to the formation of tea cream by binding with proteins. In order to retain the TFDG, β-lactoglobulin (β-LG) was used to bind with TFDG and avoid the formation of tea cream. The results of physicochemical tests and entropy weight-TOPSIS showed that the best β-LG-TFDG dispersion (TFDG concentration: 0.468 g/L) had low particle size (37.29 nm), high electrical potential (−32.43 mv), high transmittance (88.52%), and strong antioxidant activity (84.82%), when the preheated temperature of β-LG was 85 °C and the molar ratio was 1:2. The multispectral experiment results showed that TFDG interacted with β-LG via static quenching, and preheated treatment of β-LG enhanced the interaction between β-LG and TFDG. CD spectroscopy suggested that TFDG induced slight changes in the secondary structure of β-LG. The results of molecular dynamics showed that preheated treatment leading in the changes in tertiary structure of β-LG, opening of key ring region of β-LG and exposing the active cavities of β-LG, which enhances the intermolecular forces between TFDG and β-LG. What's more, molecular docking was proved that preheated treatment of β-LG enhances the hydrophobic interactions and hydrogen bonds, which dominated the interaction between TFDG and β-LG. The results proposed in this research could further reducing tea cream formation and improving the healthy and sensory performances of tea beverage by using preheated β-LG without preserving both the tea pigments and the active nutrients.

A semantic segmentation algorithm for automated rapid melt pool identification from cross-sectional micrographs

Melt pool contours are an important empirical process measurement for metallic additive manufacturing. Melt pool boundaries indicate the maximal extent of the melting temperature contour. Melt pool boundaries characterize the effects of process parameters on melt pool size and variability and provide calibration and validation data for process simulations predicting thermal fields and microstructure. Serial cross sectioning of samples can produce numerous micrographs valuable for building robust melt pool contour datasets. However, the acquisition of contours from micrographs by hand is error prone and prohibitively time consuming for datasets large enough to capture variation within individual scan tracks and across a range of process conditions. In this work, we propose a semantic segmentation algorithm for automating melt pool contour acquisition from micrographs. The proposed algorithm is demonstrated on datasets from two different single scan track experiments conducted on a Powder Bed Fusion-Laser Beam platform using a bare Ti-6Al-4 V plate and an Inconel 718 plate with a 40 μm powder layer at different preheat temperatures. The algorithm was successfully trained and predicted the melt pool boundaries in the 300 image Ti-6Al-4 V dataset with 95% accuracy and an estimated reduction of 91% in processing time compared to data acquisition by hand. For the 1201 image Inconel 718 dataset, the algorithm achieved 89% accuracy and an estimated 99% time savings compared to hand measurements. The results for both datasets are demonstrated with a discussion about observed variability in the melt pool characteristics.

Heat-assisted friction stir incremental sheet forming of thermoplastics

Incremental sheet forming (ISF) has been attracting increasing interests for customised manufacture of thermoplastics, but the application in high-performance and hard-to-form thermoplastics is still a challenge. This paper develops a new heat-assisted friction stir incremental sheet forming (HAFS-ISF) process to form polyether ether ketone (PEEK) and polymethyl methacrylate (PMMA, acrylic). Flexible heating tapes and tool rotational friction heat the thermoplastic sheet on both bottom and top surfaces, which maintain the sheet material at high temperature and reduce the through-thickness temperature gradient. Results are given for the effect of key parameters on forming temperature, force, accuracy and thickness distribution. Spindle speed has the most significant effect on all the studied aspects, followed by the pre-heating temperature, while feed rate and step size have less effect. With lower spindle speed of 100 rpm, the through-thickness temperature gradient is improved. Compared with PEEK parts, more uniform forming temperature and smaller forming force can be observed for PMMA parts. But the material brittleness causes worse formability, and the severer twist and stretching effect affect the forming accuracy of PMMA parts. Forming accuracy, fracture and twist are discussed by developing analytical models. The model for forming accuracy considers the initial bending effect and springback. The fracture is discussed by modelling the stress triaxiality and equivalent strain distribution under contact. While the model for twist considers effect of the applied torque on shear strain energy and continuous accumulation of twist along the tool path. By comparing analytical models and testing observations, the effectiveness of the models is confirmed to understand the underlaying mechanisms and to address a few challenges.

Additive manufacturing Ti-22Al-25 Nb alloy with excellent high temperature tensile properties by electron beam powder bed fusion

Additive manufacturing of TiAl alloys remains challenging due to their poor high-temperature tensile properties. In this work, electron beam powder bed fusion (PBF-EB) was applied to fabricate Ti-22Al-25 Nb alloy with a high pre-heating temperature (830℃), achieving a breakthrough in improving the tensile properties of TiAl alloys by additive manufacturing. The microstructure and tensile properties of Ti-22Al-25 Nb fabricated by laser beam powder bed fusion (PBF-LB) and PBF-EB were investigated. Excellent tensile strength (803 MPa) at 650℃ was obtained by PBF-EB, which was attributable to the precipitation and growth of the O phase at a suitable pre-heating temperature. An in-depth microstructure analysis of the deformation and fracture mechanisms of the as-printed samples was performed via Scanning Electron Microscopy (SEM), Electron Backscatter Diffraction (EBSD) and Transmission Electron Microscopy (TEM). The area fraction of the O phase in the PBF-EB sample was approximately 6 times higher than that of the PBF-LB sample. The PBF-EB sample exhibited transgranular fracture at 650 °C, in contrast to the PBF-LB samples. The shape and quantity of the O phase and β phase played an important role in improving the tensile properties of the Ti-22Al-25 Nb alloys at high temperature.

A MICRO-COOLED HIGH-STRENGTH WELD FOR HEAVY TRANSPORT MEANS

This paper focuses on the technical problem of repairing the main operating elements of heavy vehicles (semitrailers, dumps, and drums). If these vehicles are in service, significant changes in work schedules can occur, and costs can be generated immediately. Therefore, using the correct technology for repairs is crucial to minimizing financial and logistic difficulties. The article aims to analyze the mechanical properties of an MMA (Manual Metal Arc) welding (covered electrodes) joint made of Hardox 450 steel. This kind of material has a martensitic microstructure, which is difficult to weld because of changes in the components to the other ones during the joint process. Other inconveniences are related to the different chemical composition of steel and covered electrodes, their mechanical resistance, and thermodynamic conditions (consisting of the pre-heating temperature and the cross-pass temperature). Therefore, the joint quality should be determined using a few methods. In this case, NDT (magnetic and radiographic tests) and DT (microstructural analysis and static as well as fatigue tests) were used. All obtained results have enabled the proposed guides for the MMA welding of the steel grade. This is indicated as follows: (1) the method of bevelling the sheets before welding should be used, (2) pre-heating is necessary at temperature levels of 100 C and 125 C, and (3) the recommended interstitial temperature is between 170 C and 200°C.

Soy protein isolate-catechin complexes conjugated by pre-heating treatment for enhancing emulsifying properties: Molecular structures and binding mechanisms

This study aimed to investigate the impact of different pre-heating temperatures (ranging from 40 °C to 80 °C) on the interactions between soy protein isolate (SPI) and catechin to effectively control catechin encapsulation efficiency and optimize the emulsifying properties of soy protein isolate. Results showed that optimal heat treatment at 70 °C improved catechin encapsulation efficiency up to 93.71 ± 0.14 %, along with the highest solubility, enhanced emulsification activity index and improved thermal stability of the protein. Multiple spectroscopic techniques revealed that increasing pretreatment temperature (from 40 °C to 70 °C) altered the secondary structures of SPI, resulting in a more stable unfolded structure for the composite system with a significant increase in α-helical structures and a decrease in random coil and β-sheet structures. Moreover, optimal heat treatment also leads to an augmentation of free sulfhydryl groups within complex as well as exposure of more internal chromophore amino acids on molecular surface. Size-exclusion high-performance liquid chromatography and SDS-PAGE analysis indicated that the band intensity of newly formed high-molecular-weight soluble macromolecules (>180 kDa) increased as the pre-heating temperature rose. Furthermore, fluorescence spectroscopy and molecular docking analysis suggest that hydrophobic and covalent interactions were involved in complex formation, which intensified with increasing temperature.

An experimental investigation of liquid immersion cooling of a four cell lithium-ion battery module

The thermal management of a lithium-ion battery module subjected to direct contact liquid immersion cooling conditions is experimentally investigated in this study. Four 2.5 Ah 26650 LiFePO4 cylindrical cells in a square arrangement and connected electrically in parallel are completely immersed in the dielectric fluid Novec 7000. The thermal and electrical behaviour of the module is assessed at charging and discharging rates of 1C to 4C. Experiments are conducted with initially ambient temperature liquid, resulting in single phase natural convection cooling, as well as preheated liquid temperatures of 33 °C ± 0.5 °C to study the influence of the phase change process under pool boiling conditions. Superior performance is observed when two-phase immersion cooling conditions are established for discharge rates of 2C and above, limiting the average cell temperature rise to 1.9 °C at the end of 4C discharge, corresponding to a maximum temperature of 34.7 °C. For the most onerous charging rate of 4C, considered fast charging, this maximum temperature rise is limited to 1.3 °C, corresponding to a maximum temperature of 35 °C. Vigorous boiling is observed from the cells' electrodes, leading to more effective heat transfer from the locations of high heat flux. Excellent module thermal homogeneity is exhibited, maintaining a maximum temperature difference of 1.2 °C for all cases investigated. The axial temperature gradients of the module's individual cells are also greatly reduced under two-phase conditions. The influence of cell spacing within the module is also investigated for inter-cell spacings of 0.25D and 1D, where D is the cell diameter. Marginally improved heat transfer performance is observed for the more closely spaced cell arrangements, reducing the maximum cell temperatures and thermal inhomogeneity within the module.

Beta irradiation-induced thermoluminescence: Glow curve analysis and kinetic parameters in combustion-synthesized undoped Ca4YO(BO3)3

This study examines the thermoluminescent (TL) properties of undoped Ca4YO(BO3)3 phosphor, focusing on how it behaves under a variety of experimental conditions. The IRSL-TL 565 nm was chosen as the appropriate detection filter among various optical detection filter combinations. During the preheating trials conducted at a rate of 2 °C/s, the TL peak exhibited increased intensity, particularly around 200 °C. The experimental outcomes demonstrated a reliable linear relationship (R2 = 0.996 and b = 1.015) in the dose response of undoped preheated Ca4YO(BO3)3 within the range of 1–200 Gy. The investigation encompasses a range of techniques, including the TM-Tstop method, computerized glow curve deconvolution (CGCD) analysis, and theoretical modelling. The application of the TM-Tstop method to samples irradiated with a 5 Gy dose revealed distinct zones on the TM versus Tstop diagram, signifying the presence of at least two discernible components within the TL glow curve, specifically, a single general order kinetics peak and a continuous distribution. The analysis of activation energy versus preheated temperature exhibited a stepwise curve, indicating five trap levels with depths ranging between 1.13 eV and 1.40 eV. The CGCD method also revealed the superposition of at least five distinct TL glow peaks. It was observed that their activation energies were consistent with the Tm-Tstop experiment. Furthermore, the low Figure of Merit (FOM) value of 1.18% indicates high reliability in the goodness-of-fit measure. These findings affirm the reliability and effectiveness of the employed methods in characterizing the TL properties of the Ca4YO(BO3)3 phosphor under investigation. Theoretical models, including the semi-localized transition model, were introduced to explain anomalous observations in TL glow peak intensities and heating rate patterns. While providing a conceptual framework, these models may require adjustments to accurately capture the specific characteristics uncovered through CGCD analysis. As a potential application, the study suggests that the characterized TL properties of Ca4YO(BO3)3 phosphor could be utilized in dosimetric applications, such as radiation dose measurements, owing to its reliable linear response within a broad dose range.

Evaluation of degree of blending and its effect on performance of recycled hot-mix asphalt under different preheating conditions

This research comprehensively explored the function of preheating temperature and quantified the contribution of degree of blending (DoB) to performance of recycled hot-mix asphalt (HMAs). Five groups were designed, including no blending group, full blending group, and three experimental groups at preheating temperatures of 60, 110, and 160 °C. It can be found that the preheating temperature played a positive impact on DoB and performance of recycled HMAs. As the preheating temperature increased by 50 °C, about 0.13%–0.2% of reclaimed asphalt binder can be additionally activated, and the tensile strength ratio, shear strength, and fracture energy of recycled HMAs can improve by around 6%–8%, 0.07–0.15 MPa, and 304.2–335.4 J·m2, respectively. Moreover, the results showed that the performance of recycled mixes designed at preheating temperature of 60 °C was close to that of no blending group, while the mixes designed at a preheating temperature of 160 °C can reach to those of full blending group.

Mechanochromic properties of acridine heterocyclic derivatives with a donor-acceptor configuration

The mechanochromic properties of two acridine heterocyclic derivatives with a donor-acceptor configuration, 10-phenyl-10-(4-(7,7,13,13-tetramethyl-7,13-dihydro-5H-indeno[1,2-b]acridin-5-yl)phenyl)anthracene-9(10H)-one (DpAn-InAc) and 10-(4-(5,5-dimethylbenzofuro[3,2-c]acridin-13(5H)-yl)phenyl)-10-phenylanthracen-9(10H)-one (DpAn-BzAc), were investigated. The effect of different grinding time (10 and 20 min) and pre-heating temperature (−10, 100, and 120 °C) on the mechanochromic performance of DpAn-InAc and DpAn-BzAc were analyzed. The average red shift of the emission peak was 18 nm for DpAn-InAc powder under grinding stimuli, with the long grinding time (20 min) bringing the greatest shift, while both the highest (120 °C) and the lowest (−10 °C) pretreat temperature brought a greater impact on the luminescent peak. On the contrary, the ground DpAn-BzAc preheated at 100 °C showed the maximum wavelength shift, which was ascribed to the lower glass transition temperature of DpAn-BzAc. Meanwhile, the discolored sample could be recovered by ethanol fumigation, proving that the discoloration was reversible. X-ray diffractograms revealed that under the anisotropic force, the microcrystalline structure of DpAn-InAc and DpAn-BzAc were destroyed, resulting in the shift of the fluorescence peak. The fluorescence shift of DpAn-BzAc was more obvious than that of DpAn-InAc, while its recovery was inferior compared to DpAn-InAc, which was due to its looser molecular structure. Finally, DpAn-InAc and DpAn-BzAc were applied in delivering rewritable encrypted information and both of the two molecules have shown capabilities in transmitting coded information. This work sheds light on using the molecule with donor-acceptor molecular structure in the stimuli-responsive field, and shows their potential application in transmitting encrypted information.

The preparation and formation mechanism of ferrochrome slag-based high-strength ceramic aggregate and its impact on the performance of concrete

Solid waste, such as ferrochrome slag (FCS), has been extensively studied for its potential use as a construction material. This research focuses on utilizing FCS as the primary raw material to produce a high-strength ceramic aggregate, referred to as FCS-HSCA. The impact of calcination parameters on the performance of FCS-HSCA was investigated, while the underlying transformation mechanism was comprehensively explored. Subsequently, concrete with FCS-HSCA was prepared, and its influence on the performance of concrete was evaluated. The results reveal that the optimal performance of FCS-HSCA is achieved with a compressive strength of 310.3 MPa, a water absorption of 0.27%, and an apparent density of 2930 kg/m3. These characteristics are associated with specific parameters during the calcination stages, namely a preheating temperature of 1100 ℃, preheating time of 60 min, calcination temperature of 1500 ℃, and calcination time of 180 min. Moreover, the increased crystalline phases promote the solid dissolution of chromium into Mg(Al1.5Cr0.5)O4, and the occurrence state of chromium is stable during the preparation of FCS-HSCA. This results in a decreased leaching value from 0.439 mg/L to 0.188 mg/L, reducing the impact on the environment and human health. Additionally, replacing FCS with FCS-HSCA in concrete enhances its compressive strength from 59.9 MPa to 66.1 MPa. This improvement is attributed to a notable reduction in the diameter of pores on the surface of FCS-HSCA, leading to a denser structure and improved bondability with cementitious composites. Finally, this novel approach maximizes the utilization of material characteristics while enhancing the stability of waste FCS.

Vibrational anharmonicity of A-band related optical center and its temperature dependence studied by femtosecond laser excitation in bulk natural diamond

Unusual A-band spectra with well-resolved quasi-periodical phonon progressions of multiple peaks (N\(\sim \)9) were excited in a natural diamond by 515-nm, 300-fs laser pulses at variable pre-heating temperatures of 24-200oC. The non-radiative multi-phonon part of the relaxation path was comparable with the total relaxation energy (zero-phonon line energy), pointing out some extended defects (e.g., dislocations) as the recombination center of the A-band emission. The derived temperature dependences of the peak intensities, separations and half-widths of the separate spectral peaks in the A-band phonon progressions indicate the different trends for vibration-free zero-phonon transition and vibration-related lower-energy transitions to high vibrational levels of the bottom state – lower thermal damping and more softened phonon for the zero-phonon transition, also implying the extended defect origin of the A-band photoluminescence.

Heat input optimization for the ignition of self-sustained smoldering remediation of contaminated soils using concentrated solar power

In this paper, we explore the industrial-scale feasibility of using concentrated solar power (CSP) as the heat source in the smoldering remediation of petroleum-contaminated soil. Approximately 5 L soil samples were loaded in a narrow-channel reaction chamber and heated from the bottom with CSP to identify the required heat input to achieve ignition. Both petroleum and granular activated carbon (GAC) were used as combustible media. GAC was selected as a cleaner-burning alternative to petroleum and could emulate petroleum-contaminated soil at a mixture of 40 g GAC per kg pool sand on a 1.5 cm bed of GAC. This mixture of GAC showed robust ignition with a minimum power input of 240 W, which was slightly higher than the power input required to ignite industrially generated petroleum-contaminated soil. Preheat temperatures in excess of 300°C were achieved in most experiments, allowing for robust ignition of the smoldering remediation process. CSP was collected using parabolic reflectors 600 mm in diameter and was delivered to the reaction chamber with fiber optic bundles. Each solar concentrator delivered between 50 and 80 W to the reaction chamber, and four concentrators were required to reliably achieve the required power input.

Excited state lifetime of electron trapping centres in alkali feldspars

The development of the infrared photoluminescence (IRPL) signal enables the direct non-destructive probing of the trapped electron population in feldspars. Whilst IRPL offers new perspectives for luminescence dating, it also enables detailed, site-selective measurements of the dosimetric defects emitting IRPL at 880 nm (IRPL880) and 955 nm (IRPL955), allowing improved understanding of luminescence phenomena in feldspars.We perform time-resolved IRPL measurements to investigate the excited state lifetimes of IRPL880 and IRPL955 electron trapping centres in chemically and structurally different feldspars. We analyse the time-resolved off-time data with three exponentially decaying components. The contribution of the fast component (τ1) fitted to the IRPL880 data is minor and its lifetime is consistent with the switch off time of the 830 nm excitation laser. The two longer lifetimes (τ2 and τ3) dominate the IRPL880 and IRPL955 signals. The τ2 values range from 2 μs to 6 μs for IRPL880 and from 2 μs to 7 μs for IRPL955, whereas τ3 ranges from 7 μs to 25 μs for IRPL880 and from 8 μs to 22 μs for IRPL955, with an average cluster value of ∼20 μs. We observe a weak decreasing trend in τ3 lifetime with decreasing K-feldspar content. Systematic thermal depletion of the trapped electron population results in decreasing τ2 lifetimes with increasing preheat temperature, but a negligible change in τ3. We suggest that time-resolved-IRPL lifetimes not only reflect the exited state lifetime of the electron trapping centre, affected by excited-to-ground state transition as well as tunnelling, but also a direct recombination from the band-tail states. The long excited-state lifetime of the order of 20 ∼ μs (the average cluster value) allows for tunnelling induced recombination from the excited state, which is supported by the fact that reported lifetimes for time-resolved-IRSL (infra-red stimulated luminescence) are shorter than those of time-resolved-IRPL.

Numerical Analysis and Experimental Study on Side Dam Temperature and Stress Field of Two‐Roll Casting

The side sealing technology is crucial for ensuring the quality and process stability in twin‐roll casting (TRC). Investigating the temperature and stress distribution in side dams under operational conditions is vital, especially in understanding the causes of side dam fractures. Optimal performance of side dam materials is achieved when the boron nitride (BN) matrix is fine and homogeneous, with zirconium dioxide (ZrO2) and silicon carbide (SiC) particles evenly dispersed throughout. The fracture of the side dam after casting is mainly caused by BN interlamellar tear. The coexistence of BN lamellar tearing and BN layer fracture leads to the fracture of the side dam during the casting process. Through finite element simulation, the effects of variables such as pouring temperature, preheating temperature, and side dam thickness on temperature and stress distribution were analyzed. The findings indicate that a preheating temperature range of 1200–1300 °C minimizes thermal stress in the side dam. Building on these findings, a composite structure for the side dam is developed. Both internal and external composite structures have shown significant effectiveness in reducing thermal stress. These results are pivotal in extending the service life of side dams and enhancing the stability of the TRC process.

Effects of fuel preheat temperature on soot formation in methyl linolenate co-flow diffusion flames

Effects of fuel preheat temperature on soot formation in methyl linolenate co-flow diffusion flames