Optimum Sintering Temperature Research Articles

Effect of Sintering Temperature on Ceramic Membrane Fabricated Using Coal Flyash and Natural Clay for Lignin Recovery

This study explores the utilization of coal fly ash combined with natural clay as a precursor for creating ceramic membranes through the uniaxial compaction method, aiming at lignin separation. These membranes were sintered at varying temperatures from 600 to 1000 °C. Thermal Gravimetric Analysis (TGA) revealed the robust thermal stability of the membranes. Fourier Transform Infrared (FTIR) analysis affirmed the presence of silica and alumina within the membranes. X-ray Diffraction (XRD) peaks indicated the crystalline structure and the presence of metal oxides originating from the fly ash and clay components. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) images illustrated the porous nature and rough surface of the ceramic membranes. The average pore radius of the fabricated membrane expanded from 43.12 to 7.91 nm with increasing temperature. Concurrently, membrane flux decreased from 4.13 to 0.96 ×10-6 m3/m2 s with higher temperatures. Lower contact angles indicated the hydrophilic properties of membranes. All membranes exhibited superior corrosion resistance and negative zeta potential, owing to the significant silica content in the fly ash. Lignin separation efficiency increased from 65 % to 81 % with increasing temperatures. The optimal sintering temperature was determined to be 800 °C, achieving a lignin recovery greater than 76 % and a membrane permeability of about 7×10-9 m3/m2 s kPa. Thus, the fly ash-clay-based ultrafiltration membranes synthesized in this study offer the potential for lignin biomass recovery from biorefinery effluent.

Sintering parameter investigation for bimetallic stainless steel 316L/inconel 718 composite printed by dual-nozzle fused deposition modeling

Purpose Fused deposition modeling (FDM) nowadays offers promising future applications for fabricating not only thermoplastic-based polymers but also composite PLA/Metal alloy materials, this capability bridges the need for metallic components in complex manufacturing processes. The research is to explore the manufacturability of multi-metal parts by printing green bodies of PLA/multi-metal objects, carrying these objects to the debinding process and varying the sintering parameters. Design/methodology/approach Three different sample types of SS316L part, Inconel 718 part and bimetallic composite of SS316L/IN718 were effectively printed. After the debinding process, the printed parts (green bodies), were isothermally sintered in non-vacuum chamber to investigate the fusion behavior at four different temperatures in the range of 1270 °C−1530 °C for 12 h and slowly cooled in the furnace. All samples was assessed including geometrical assessment to measure the shrinkage, characterization (XRD) to identify the crystallinity of the compound and microstructural evolution (Optical microscopy and SEM) to explore the porosity and morphology on the surface. The hardness of each sample types was measured and compared. The sintering parameter was optimized according to the microstructural evaluation on the interface of SS316L/IN718 composite. Findings The investigation indicated that the de-binding of all the samples was effectively succeeded through less weight until 16% when the PLA of green bodies was successfully evaporated. The morphology result shows evidence of an effective sintering process to have the grain boundaries in all samples, while multi-metal parts clearly displayed the interface. Furthermore, the result of XRD shows the tendency of lower crystallinity in SS316L parts, whilst IN718 has a high crystallinity. The optimal sintering temperature for SS316L/IN718 parts is 1500 °C. The hardness test concludes that the higher sintering temperature gives a higher hardness result. Originality/value This study highlights the successful sintering of a bimetallic stainless steel 316 L/Inconel 718 composite, fabricated via dual-nozzle fused deposition modeling, in a non-vacuum environment at 1500 °C. The resulting material displayed maximum hardness values of 872 HV for SS316L and 755.5 HV for IN718, with both materials exhibiting excellent fusion without any cracks.

Crystal Structure, Infrared Reflection Spectrum, and Improved Microwave Dielectric Characteristics of Ba4Sm28/3Ti18O54 Ceramics via One-Step Reaction Sintering.

High-k Ba4Sm28/3Ti18O54 ceramics with improved microwave dielectric characteristics were successfully fabricated using the one-step reaction sintering (RS) route. The sintering characteristics, microstructure, crystal structure, infrared reflection spectrum, and microwave dielectric characteristics of Ba4Sm28/3Ti18O54 ceramics prepared by the RS route were systematically investigated. Samples prepared by the RS route exhibited single-phase orthorhombic tungsten-bronze structure and dense microstructure at optimum sintering temperature. Compared with the conventional solid-state (CS) process, the Ba4Sm28/3Ti18O54 ceramics fabricated by the RS route presented a smaller temperature coefficient (TCF), a higher quality factor (Q × f), and a higher permittivity (εr). The improved microwave dielectric characteristics were highly dependent on the theoretical permittivity, atomic packing fraction, suppression of Ti3+, and Ti-site bond valence. Excellent combined microwave dielectric characteristics (TCF = -7.9 ppm/°C, Q × f = 9519 GHz, εr = 80.26) were achieved for Ba4Sm28/3Ti18O54 ceramics prepared by RS route sintered at 1400 °C, suggesting the RS route was a straightforward, economical and effective route to prepare high-performance Ba4Sm28/3Ti18O54 ceramics with promising application potential.

Achieving superior compressive strength-ductility synergy in a novel ODS-CrFeNi/AlCrFeNi heterostructured high-entropy composite

A novel high-entropy heterostructured composite (ODS-CrFeNi/AlCrFeNi) was fabricated by powder metallurgy method. The microstructure and mechanical properties of the composites with various sintering temperatures (950 °C to 1100 °C) and various addition amounts (0% to 20%) of FCC-structured reinforcing phase (ODS-CrFeNi) were investigated. The results revealed a reduction in porosity and an increase in relative density, reaching up to 99% with increasing sintering temperature. The optimal sintering temperature is 1100 °C. In the composites with the addition of 5% and 10% ODS-CrFeNi reinforced phases, spinodal decomposition (SD), forming BCC and B2 phases, takes place both in the matrix and in the reinforcing phase. As the reinforcing phase content is increased to 15% and 20%, SD occurs exclusively in the matrix while is suppressed in the reinforcing phase. The reinforcing phase consists of hard BCC structured Cr rich phases and soft FCC-structured FeNi phases, forming a gradient network structure. The composite with 15% reinforcing phase exhibits high hardness of 841 HV and compressive yield strength, ultimate strength and strain of 6960 MPa, 7690 MPa and 15.5%, respectively, which are 2.5, 2.7 and 1.9 times higher than those of the reference alloys (without reinforcing phase). The excellent strength-ductility synergy originates from the unique gradient network structure formed in the reinforcing phase, i.e. complex heterogeneous structure, which results in hetero-deformation induced (HDI) strengthening for higher strength and HDI strain hardening for higher ductility.

Microstructure, mechanical and corrosion property of neutron and γ-ray shielding (Gd2O3+W)/Al composites

In this study, a neutron and γ-ray absorbing (Gd2O3+W)/Al composite was fabricated by vacuum sintering. Firstly, through Monte Carlo Neutron and Photo Transport Code (MCNP) calculations, the content of Gd2O3 and W in the composite was determined to be 10 wt.% and 25 wt.%, respectively. Then, the influence of sintering temperature and sintering time on the microstructure, density, compression properties and electrochemical corrosion behavior of the (Gd2O3+W)/Al composites were investigated. The results indicate that sintering temperatures below 600 °C and sintering times shorter than 2 hours led to insufficient density of the composite. Conversely, sintering temperatures above 600 °C and sintering times longer than 2 hours caused W to agglomerate, resulting in a decrease in the density of the composite and a deterioration of its electrochemical performance. Therefore, the optimal sintering temperature and sintering time for the (Gd2O3+W)/Al composites were determined to be 600 °C and 2 hours, respectively. Finally, the immersion corrosion performance in H3BO3 solution of the composite fabricated by the optimal process parameters was studied in detail. It was found that pitting was the main corrosion form of the (Gd2O3+W)/Al composite, and an oxidation film mainly composed of Al2O3 was formed on the surface.

Effect of Ni Substituted MgZrTa2O8 Ceramics on Sintering Characteristics and Microwave Dielectric Properties

Herein, Mg1−xNixZrTa2O8 (x = 0, 0.1, 0.3, 0.5, 0.8, 1) ceramics are synthesized using a solid‐phase reaction method. Ni2+ replacing Mg2+ improves the drawback of high sintering temperature and poor temperature stability. The samples have a relative density above 95% at the optimal sintering temperature. The sintering temperature of Mg1−xNixZrTa2O8 reduces from 1475 to 1400 °C. And single‐phase Mg1−xNixZrTa2O8 ceramics with monoclinic wolframite structures are analyzed. According to the Rietveld refinement results, with the doping of Ni2+, the transformation of unit cell volume leads to the shift of the main peak in the X‐Ray diffraction pattern to a higher angle in 0 ≤ x ≤ 0.3 and a lower angle in 0.5 ≤ x ≤ 1. The εr of Mg1−xNixZrTa2O8 is comparable to MgZrTa2O8. At 1400 °C, the Q × f is increased from 10 598 GHz in the undoped sample to 43 041 GHz in Mg0.9Ni0.1ZrTa2O8 ceramic. The absolute values of τf of ceramic samples decrease with the excessive Ni2+. The desirable dielectric properties (εr = 20.79, Q × f = 43 041 GHz, τf = −33.04 ppm °C−1) are obtained at 1400 °C. Ni substitution is effective for MgZrTa2O8 ceramic to optimize densification temperature and retain the high Q × f value.

Obtained large room-temperature TCR of La0.67Ca0.25Sr0.08MnO3 ceramics by optimizing sintering temperature

Over the past few decades, perovskite manganese oxide Lax(CaSr)1-xMnO3 has presented new opportunities for uncooled infrared bolometers due to its exceptional electrical transport performance. In this study, La0.67Ca0.25Sr0.08MnO3 (LCSMO) ceramics were prepared at different sintering temperatures (Ts, Ts = 1450, 1470, 1490, 1510, 1530 °C) by changing the previous sol-gel preparation process parameters. The research results indicated that the tolerance factor (τ) of the ceramics is τ = 0.935, and all ceramics exhibit a Pnma space group perovskite structure with excellent crystallinity. LCSMO ceramics exhibit good crystal quality and higher room-temperature TCR (14.58 % K−1) at Ts = 1510 °C. As Ts increases, the grain size, Mn–O bond length (dMn-O), Mn–O–Mn bond angle (θMn-O-Mn) and cell volume (V) of ceramics have a slight affected. The decrease of grain boundary scattering, electron-electron scattering, and strong coupling between electrons, so the peak resistivity value of all sintered samples firstly decreases and then increases with the increase in Ts, which effectively yields ceramics with high TCR. The peak TCR value (TCRmax) increased from 8.38 % K−1 (Ts = 1450 °C) at 296.91 K to 14.58 % K−1 (Ts = 1510 °C) at 298.18 K. On the same component, the TCRmax was increased by 42 % from 8.38 % K−1 to 14.58 % K−1 at Ts = 1450 °C–1510 °C. The high room-temperature TCR of LCSMO is expected to be used in advanced uncooled infrared bolometers, providing a basis for studying the influence of Ts on the electrical transport performance of ceramics.

Enhancing the physical properties of Mo-Cu composites through plasma spheroidized spherical molybdenum powder

ABSTRACT This paper investigates the preparation of spherical molybdenum-copper (Mo-Cu) composites through the utilization of plasma spheroidization1 of molybdenum powder, followed by ‘Carbon thermal pre-reduction + Hydrogen deep reduction2’ processes. The properties of these composites are analyzed. By adjusting the mass ratio of molybdenum to copper and employing mechanical activation during high-temperature sintering, Mo and Cu are dispersed more uniformly, resulting in improved fluidity and a reduced tendency to agglomerate in x% Mo-Cu (x = 20, 40, 60, 80) composites. Experimental results demonstrate that compared to original powder Mo-Cu composites, the prepared spherical Mo-Cu composites exhibit uniform elemental distribution, regular arrangement, and reduced porosity. Among these, the 60% Mo (spherical)-Cu composites show the best dispersion and superior performance. At the optimal sintering temperature of 1250°C, the thermal conductivity of the sintered product increased from 137 Wm−1K−1 to 148 Wm−1K−1, the electrical conductivity increased from 18.9 MS/m to 21.8 MS/m, and the Vickers hardness increased from 177 HV to 209 HV.

Enhanced performance of solid oxide fuel cells using highly conductive Ca2+ and F− co-doped Gd0.2Ce0.8O1.9 buffer layer

Gadolinium-doped ceria (GDC) is the most widely used buffer layer to prevent the reaction between YSZ electrolyte and La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathode for commercial solid oxide fuel cell (SOFC). However, conductivity and sintering activity are vital to cell performance. In this paper, Ca2+ and F− co-doped GDC (Ca0.03Gd0.17Ce0.8F0.06O1.84-δ, CGDCF) is used as a buffer layer to improve the performance and stability of SOFC. The co-doped F− and Ca2+ significantly improve the sintering properties and oxygen ion transport of traditional GDC material. Meanwhile, the optimized sintering temperature is 1300 °C, with the lowest ohmic resistance. The peak power density of a cell with a CGDCF buffer layer reaches 1.809 W cm−2 at 850 °C, which is 37 % higher than that of GDC. In addition, the cell with the CGDCF buffer layer exhibits excellent stability during the 150 h test owing to the lower migration of La and Sr elements. Thus, the Ca2+ and F− co-doped GDC oxide emerges as a promising material for buffer layer applications.

Low‐temperature co‐fired ceramic application of SmTaO4 and YTaO4 with ZnO‐B2O3‐SiO2 additive

AbstractIn this study, ZnO‐B2O3‐SiO2 (ZBS) glass was employed as a sintering facilitator, enabling low‐temperature sintering of SmTaO4 and YTaO4 ceramics. The influence of varying quantities of ZBS glass on sintering behavior and phase composition was investigated to reveal the low‐temperature sintering mechanism. ZBS glass exhibits favorable wetting behavior on the SmTaO4 and YTaO4 ceramic matrices and dramatically decreases the initial shrinkage temperature of ceramics throughout the sintering process. Composited with 20 wt. % ZBS and sintered at their optimal sintering temperature, the composite ceramics of SmTaO4 and YTaO4 possess favorable microwave dielectric properties: εr = 8.46, Q×f = 15,723 GHz, and τf = –6.68 ppm/°C (at 14.339 GHz), and εr = 4.21, Q×f = 18,939 GHz, and τf = –18.92 ppm/°C (at 15.512 GHz), respectively.

Enhancing thermoelectric performance of CrN ceramics by optimizing sintering temperature

Chromium nitride (CrN) ceramics were sintered at various temperatures by plasma activated sintering, and their thermoelectric properties were explored. The formation of Cr2N phase can be suppressed by venting N2 gas into the chamber before sintering and increasing the sintering temperature to accelerate the densification process. Sintering temperature significantly impacted the thermoelectric properties. Higher sintering temperature led to an increase in the N content, reducing the electrical and thermal conductivity, and increasing the Seebeck coefficient. The single-phased CrN ceramic sintered at 1573 K exhibited excellent thermoelectric performance with a maximum power factor of 1002 μW·m−1·K−2, a thermal conductivity of 4.78 W·m−1·K−1, and a zT value of 0.20 at 973 K. Furthermore, this CrN ceramic also exhibited a high relative density of 97% and a hardness of ∼11.9 GPa. Enhanced high-temperature thermoelectric properties and excellent mechanical properties make CrN ceramics suitable for thermoelectric applications in extreme environments.

Development and characterization of Al2O3/SrAl12O19 reinforced zirconia with high fracture toughness and low-temperature degradation-resistant for dental applications

The low fracture toughness and sensitivity to low-temperature degradation (LTD) are the primary reasons for the suboptimal long-term performance of dental zirconia. Composite ceramics of zirconia have gained popularity due to their ability to combine the benefits of various reinforcements. In this study, Al2O3–SrAl12O19–3Y/4Y/5Y–ZrO2 composite ceramics were fabricated using the Pechini method, and the optimal sintering temperature and time were investigated. The relative density, microstructure, grain size, mechanical properties, and LTD resistance of the samples were characterized. The results indicated that the composite achieved optimal performance when sintered at 1500 °C for 3 h. Al2O3 and SrAl12O19 primarily influence the properties of the zirconia composite ceramics by modulating their density and grain size. With an increase in the content of Al2O3 and SrAl12O19, the relative density first increases and then decreases, while the grain size exhibits an inverse trend, resulting in an initial increase followed by a decrease in fracture toughness. Additionally, the rate of increase in the m-phase fraction of the zirconia composite slowed down, but it reached a similar level after 64 h of LTD. The incorporation of 8 vol% Al2O3 and 8 vol% SrAl12O19 into 3Y–ZrO2 resulted in a ceramic composite with the highest fracture toughness values and acceptable LTD sensitivity, measured at 5.23 ± 0.25 MPa m1/2 and 48.35 ± 5.70% m-phase (LTD 64 h), respectively. This composite also exhibited high bending strength (990.09 MPa) and hardness (16.52 GPa), making it a promising alternative to conventional 3Y-TZP ceramics commonly used in dentistry.

Research on Sol-Gel Synthesis of Low-Temperature Na2O-B2O3-SiO2 Vitrified Bonds and Preparation of High-Strength Stacked Abrasives Using the Molding and Crushing Method.

Currently, the sol-gel technique is employed in the synthesis of high-performance vitrified bonds; however, its application in the fabrication of stacked abrasives has been minimally explored. Furthermore, the methods utilized in the production of abrasive particles for stacked abrasives are technically challenging and incur high costs, which hinders their actual industrial application. Consequently, this study utilizes the sol-gel approach to synthesize a Na2O-B2O3-SiO2 ternary system vitrified bond powder and employs a molding and crushing method, which offers a lower technological barrier and reduced preparation costs, for the production of abrasive particles subsequently fabricating corundum stacked abrasives. Upon setting the binder composition to a molar ratio of n(SiO2):n(B2O3):n(Na2O) = 65:23:12, it was observed that the crystallization within the glass matrix was minimized and the optimal sintering temperature for the synthesized laminate abrasive to be sustained at 820 °C. At the aforementioned temperature, the binder melt is capable of flowing uniformly amongst the abrasive granules, thereby ensuring a robust encapsulation of the particles. The average single particle compressive strength of the prepared corundum stacked abrasive with a grain size of forty mesh can reach the highest of all composition points at 28.56 N and the average single particle compressive strength of the prepared diamond stacked abrasive is 28.14 N.

Research on the extraction of rare earth elements from ash-slag waste

The research investigates the patterns of rare earth elements (REE) extraction from ash-slag waste of thermal power plants using sintering processes. The aim of the study was to determine the optimal parameters for the process: the composition of the flux, the ratio of the sintering flux to the waste, and the sintering temperature. It has been shown that the change in the type of sintering reagent, its ratio to the waste, and the process temperature significantly affect the degree of REE extraction from the insoluble form in ash-slag to the soluble form in sinter. The optimal sintering temperatures (300–4500C) for the extraction of REE from ash-slag waste have been determined. The influence of various sintering reagents on the process of REE extraction from ash-slag waste has been investigated. It has been shown that the use of sodium hydroxide as a sintering reagent allows increasing the degree of REE extraction from waste up to 100%. Based on the analysis of the obtained experimental data, the main technological parameters of REE extraction in sinter have been determined.

Formation of composites with an aluminum matrix reinforced with tungsten carbide nanoparticles

Relevance. The fact that composites with a metal matrix and structural products based on them are in great demand in various industries, including the automotive industry, aerospace industry, and shipbuilding. Aluminum matrix composites are the most popular since they combine the excellent ductility, low density, good corrosion resistance of aluminum and the high strength, hardness and wear resistance of a ceramic reinforcing component. Aim. To obtain bulk Al-WC metal matrix composites with different contents of the reinforcing phase and with increased physical and mechanical characteristics using spark plasma sintering. Objects. Sintered bulk products made of pure aluminum and obtained at 400, 450, 500, 550, 600°C and bulk metal matrix composites Al-1%WC, Al-5%WC, Al-10%WC, Al-15%WC obtained at 600°C. Methods. Spark plasma sintering; X-ray diffractometry (XRD phase analysis); scanning electron microscopy; indentation (microhardness measurement). Results. The authors have obtained bulk composite metal matrix products with an aluminum matrix and tungsten carbide as a reinforcing component. Compacting mixtures of nanosized initial powders of aluminum and tungsten carbide using spark plasma sintering made it possible to obtain products with a WC content of 1 to 15 wt %. Taking into account the results of a preliminary series of experiments, when pure aluminum samples were sintered to determine the optimal sintering temperature, bulk composite materials were obtained. A distinctive feature of the obtained samples is their high degree of compaction, which is due to the simultaneous application of a heating current and external pressure, coupled with the relative preservation of the fine-grained structure of the material due to the short process time. The analysis of various sintering modes revealed the need to carry out sintering of composites at 600°C. The research has shown that, although adding a reinforcing phase to a metal matrix significantly reduces the degree of compaction of the material from 97.45% in the absence of an additive to 62.32% with the addition of 15%WC, an increase in the microhardness of products is observed when the concentration of the reinforcing component increases from 3.95 to 5.75 HV. This proves the possibility of reinforcing a metal material using ceramic WC particles. The results can be used in a variety of structural applications, including automotive and aerospace.

Influence of sintering temperature on structural and optical properties of pure and Cl-doped ZnO nanoparticles

In this study, we conducted a detailed analysis of the sintering process of both pristine and 25 mg/g Cl-doped ZnO nanoparticles at varying temperatures to determine the optimum sintering temperature. Our findings revealed an optimal sintering temperature of 600 °C, resulting in higher phase purity (only hexagonal ZnO phase), smaller particle sizes of about 88–92 nm, and higher emission intensity for both pristine and Cl-doped ZnO nanoparticles. The band gap reduces from 3.63 eV to 3.20 for pristine and 3.63 eV to 3.10 for Cl-doped ZnO nanoparticles by increasing the sintering temperature from 200 °C to 1000 °C. The introduction of Cl in the ZnO lattice introduced a new defect level, having a broadband excitation band peaking at 374 nm. The luminescence of ZnO peaked at approximately 503 nm, which can be attributed to the transition from oxygen vacancies in the ZnO lattice. Notably, the emission intensity of the Cl-doped samples sintered at 600 °C was found to be 6.5 times higher than that of the pristine ones. Moreover, we found that the luminosity of ZnO:Cl nanoparticles was around 68% that of ZnS:Ag nanoparticles, which are typically used for radon detection and have similar efficiency to standard Lucas cells. Our preliminary findings suggest that Cl-doped ZnO nanoparticles sintered at 600 °C for 5 h could effectively develop radiation detectors, particularly for radon monitoring and related applications.

Preparation and performance of aluminosilicate fibrous porous ceramics-supported catalyst for NOx removal

In this study, we report a new aluminosilicate fibrous porous ceramics-supported catalyst for the removal of [Formula: see text]. The influence of raw materials and sintering process on the structure and properties of aluminosilicate fibrous porous ceramics was studied. The composition and the structure of the catalysts were characterized by XRF, XRD, SEM-EDS, and XPS analysis, and the experiments of denitrification were performed to determine the influence of the porous structure and the calcination process on the denitrification efficiency. The results indicated that the glass fibers facilitate the formation of a uniform porous network structure within aluminosilicate fibrous porous ceramics, and that the optimal sintering temperature is 1000∘C. Under the condition, the loaded catalysts were highly dispersed on the surface of aluminosilicate fibrous porous ceramics, which possessed high porosity and large average pore sizes. The aluminosilicate fibrous porous ceramics-supported catalyst exhibited excellent denitrification efficiency and catalytic stability, which is expected to be used for the treatment of [Formula: see text] in flue gas.

Effect of pressure on sintering behavior of polycrystalline diamond

Polycrystalline diamond composites (PDC) have been used as a cutting material in a multitude of fields, from mechanical processing to oil and gas drilling. In this study, PDC samples were prepared under high pressure and high temperature (HPHT) conditions within a pressure interval of 5.5 to 10.5 GPa by sintering diamond powder (average grain size ~3 μm) with WC-10 wt% Co substrate. Samples obtained with varying sintering pressures and temperatures were characterized using Vickers hardness tester, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results revealed that: (1) within a specified material system, each distinct sintering pressure condition corresponds to a unique optimal sintering temperature that yields the pinnacle of consolidation efficiency in samples. This optimal temperature exhibits a linearly increasing trend with rising sintering pressure; (2) at the intersection where the sintering pressure attains its optimal match with temperature, an increase in pressure fosters more intimate contact and stronger inter-grain bonding among diamond particles, thus amplifying the DD bond formation effect, which consequently leads to a linear enhancement in the Vickers hardness values of PDC with increasing sintering pressure; (3) simultaneously, under conditions of optimal temperature matching, elevating the sintering pressure notably decreases the cobalt content within the polycrystalline diamond layer of PDC samples. These findings furnish crucial experimental evidence for optimizing PDC material properties, significantly contributing to the advancement of both theoretical exploration and technological innovation within the field, carrying profound academic value and practical guidance implications.

Synthesis, properties, and applications of all-solid-state reference electrode based on AgTi2(PO4)3

High-density AgTi2(PO4)3 as a solid electrolyte was synthesised by a high-temperature solid-state process. The optimal sintering temperature was determined to obtain the best structural and electrical performance. Based on the as-prepared AgTi2(PO4)3 fast-ion conductor, a new type of all-solid-state reference electrode was prepared, and its electrochemical properties, such as cyclic voltammetry curves and potentials at varying pH, were investigated. A pH sensor was designed by combining an AgTi2(PO4)3 reference electrode with an Ir/IrO2 pH electrode. This pH sensor exhibited a good linear response to pH values in aqueous solutions and simulated seawater samples. In addition, a metal ion sensor, comprising the as-fabricated solid-state reference electrode, a Pt counter electrode, and a glassy carbon working electrode, was employed to quantify Cu2+, Hg2+, and Pb2+ concentrations using differential-pulse anodic stripping voltammetry. The resulting peak currents correlated with the metal ion concentrations and exhibited a low detection limit, good linearity, and wide detection range, which is suitable for performing chemical analysis in harsh marine environments.

Design, optimization, and verification of self‐lubricating ceramic tool microstructure by MC method

AbstractThe computer‐aided analysis of microstructure evolution during the sintering process of self‐lubricating ceramic tools can unveil the underlying sintering mechanism and optimize experimental parameters. In this study, a novel self‐lubricating ceramic tool material, Al2O3/SiC/h‐BN@Al2O3, was fabricated with Al2O3 as the matrix, SiC as the reinforcement phase, and h‐BN@Al2O3 as the solid lubricant. The Monte Carlo (MC) method was employed to construct a model of self‐lubricating ceramic tool material, consisting of Al2O3/SiC/h‐BN@Al2O3. Subsequently, the sintering process was analyzed to investigate the influence of particle size and content of reinforced SiC, as well as the content of coated solid lubricant h‐BN@Al2O3, sintering pressure, and temperature on the microstructure of the tool. Optimal composition and sintering parameters were determined: 3 vol% for SiC additive amount with a particle size of 0.05 μm; 5 vol% for h‐BN@Al2O3 additive amount; and an optimal sintering temperature at 1650°C. The development of self‐lubricating ceramic tool materials, Al2O3/SiC/h‐BN@Al2O3, was realized through the employment of the aforementioned parameters. Their mechanical properties and microstructure were comprehensively characterized. The bending strength, fracture toughness, and Vickers hardness of the experimentally‐prepared Al2O3/3 vol%SiC/5 vol%h‐BN@Al2O3 self‐lubricating ceramic tool material were determined to be 722.42 MPa, 6.5 MPa·m1/2, and 20.65 GPa, respectively.