Effect Of Sintering Temperature Research Articles

The Effect of Sintering Temperature on the Densification and Magnetic Performance of NiCuZn-Ferrites (CuO: 0–6 wt.%)

This article reported on the effect of Cu-content and sintering temperature on the magnetic permeability and power losses of monolithic iron-deficient NiCuZn-ferrite components with low Cu-contents aimed to be used for power applications at frequencies up to 1 MHz. In particular NiαZnb1−xCuxFe1.9O4 ferrite compositions are investigated with a constant Ni/Zn atomic ratio a/b = 0.9 and 0 < x < 0.017. As found, the addition of Cu enables the achievement of good magnetic performance at lower sintering temperatures and, therefore, lower production cost. At all Cu-contents, the initial permeability as a function of the sintering temperature passes through a maximum above which structural deterioration due to asymmetric grain growth occurs. The temperature at which this maximum permeability occurs depends on the Cu content and coincides with the achievement of the maximum density of 5.1–5.2 g cm−3 (relative density ~97%). At Cu-contents x = 0.006–0.012 and sintering temperatures 1200–1100 °C power losses (tan(δ)/μ at 1 MHz, 25 °C) οf 50 × 10−6 could be achieved and initial permeabilities (10 kHz, 0.1 mT, 25 °C) of around 400 with very good frequency and temperature stability. At CuO content higher than 4 wt.% (i.e., x > 0.012) and sintering temperatures higher than 1150 °C, pronounced microstructural disturbances due to asymmetric grain growth result in low permeabilities and high losses. It is suggested that at low CuO contents and low sintering temperatures, the densification enhancement may not proceed through Cu-rich phase segregation but through the creation of oxygen vacancies.

Effect of Clay as Additive Element in Recycling Waste Porcelain and Sintering Temperature

Porcelain tile production has been consistently growing worldwide at an approximate rate of 300 million m2/year. This implies that there is an increasing demand for porcelain raw materials. The industry's commercial success was due to the constant and continuous increase in both technical and aesthetic performance. Due to the complex nature of its raw materials, vigorous firing process and processing approach, porcelain represent the most intricate ceramic system. This paper studied effect of sintering temperature using recycled porcelain and clay as additive in the production of porcelain on physical and mechanical properties of the new product. Waste porcelain was treated with HCl acid, dried in an oven to remove the moisture content and sieve with 50µm aperture. Clay was added to the treated porcelain powder at 0%, 2%, 4%, 6%, 8% and 10% mixed with a ball mill machine, dry pressed into pallet at 91 MP and sintered at 1100 °C, 1150 °C and 1200 °C for 2 hours soaking time. Physical and mechanical properties such as volume shrinkage, mass loss, bulk density, water absorption and compressive strength as well as microstructural analysis were determined. At a sintering temperature of 1200 °C and clay composition of 2%, the maximum value of compressive strength was 863.15 MPa, indicating the overall maximum. Furthermore, at this composition, the value of the mass loss, shrinkage, bulk density and water absorption of porcelain waste with clay addition was 5.93%, 64%, 2.53% and 6.09%, respectively.

Effect of sintering temperature on microstructure and electrical properties of Na0.5Bi0.47Sr0.02TiO3-δ ceramics

In this investigation, a series of Na0.5Bi0.47Sr0.02TiO3-δ samples, sintered from 1000 to 1100 °C, were synthesized utilizing the solid-state method. The XRD results indicate that all samples exhibit a perovskite phase, with the exception of those sintered at 1100 °C, which display no discernible impurity peaks. The SEM results indicate that the average grain size exhibits an increase proportionate to the sintering temperature, which attributes to the variations in the actual Na/Bi ratio. From the study of grain conductivity we can obtain that the dominant factor affecting grain conductivity is the activation energy. At 1100 °C, the oxygen vacancy concentration emerges as the primary determinant of grain conductivity. It should be noticed that the phase transition temperature of the sample increases (350 °C→400 °C) with the increase of sintering temperature, which is due to the local A-site disorder aggravated by high temperature sintering. Therefore, reducing the sintering temperature is beneficial to improve the grain conductivity. The grain boundary conductivity initially rises, then diminishes with increasing sintering temperature. It is evident that the enhanced macroscopic grain boundary conductivity stems from a marked reduction in space charge potential within the 1000–1025 °C temperature range. Within the 1050 °C−1100 °C temperature range, the space charge potential barely changed, the significant decrease of intrinsic grain boundary conductivity can be attributed to the surge in the coverage ratio of grain boundary impurities and the number of grain boundary impurities increased caused by the rapid reduction of grain boundary area and thermal evaporation. The research on electrical performance of NBT-based oxygen-ion conductors will promote the application of NBT-based oxygen ion conductors in solid oxide fuel cells, oxygen sensors and other fields.

Vat photopolymerization of biomimetic bone scaffolds based on Mg, Sr, Zn-substituted hydroxyapatite: Effect of sintering temperature

In response to the urgent demand for innovative bone regeneration solutions, the focus of this study is to develop and characterize Mg, Sr, Zn-substituted calcium phosphate scaffolds that replicate the trabecular architecture of cancellous bone. Ion substitution represents a promising approach to improve the biological effectiveness of calcium phosphates and composite materials used in bone tissue engineering applications. Porous scaffolds mimicking the natural bone structure were additively manufactured from the photosensitive ceramic suspensions for vat photopolymerization using digital light processing. The impact of the selected trace elements (0, 1 and 5 mol.% substitution) and the sintering temperature (900, 1000, 1100, 1200, and 1300 °C) was investigated in relation to the obtained crystalline phase content, microstructure, elemental distribution, thermal stability, and mechanical properties. After sintering, in addition to hydroxyapatite, β-tricalcium phosphate was detected as a result of the added trace elements in the calcium-deficient hydroxyapatite used as a starting powder. The obtained scaffolds exhibited uniform distribution of the trace elements, and they feature 3D-designed porosity predominantly ranged from 10 to 900 μm in diameter, with an average pore size of 546.25 ± 10.95 μm. The total porosity of scaffolds was 76.24 ± 1.32 vol.% and an average wall thickness of 217.03 ± 8.98 μm, closely resembling the morphology of cancellous bone tissue. The mechanical properties of the scaffolds sintered at 1100°C, 1200°C, and 1300°C were in line with those typically observed in trabecular bone. The study demonstrates the feasibility of using custom made bioactive hydroxyapatite powders together with vat photopolymerization to design the porosity and properties of the bone scaffolds on demand, based on the requirements of individual bone defects.

A novel strategy for low-temperature fabrication of porous CA6 ceramics using reactive CaCl2-KCl medium and its influence mechanism

This paper proposes a novel strategy to fabricate porous calcium hex-aluminate (CA6) ceramics using CaCl2-KCl as reactive medium. Effects of CaCl2-KCl content and sintering temperature on microstructure and properties of porous CA6 ceramics are systematically studied. CaCl2-KCl serves as both a pore former and an additional source of CaO, eliminating the need for additional salt-washing treatment. By optimizing CaCl2-KCl content to 20wt%, porous CA6 ceramics with well cross-interlocking plate-like structures, possessing low thermal conductivity of 0.32W·(m·K)-1 (1000°C), high apparent porosity of 68.28%, and desirable compressive strength of 6.76MPa, are fabricated at 1300°C. This work not only validates the promising applicability of porous CA6 materials for thermal insulation, but also introduces an auspicious fabrication methodology for thermal insulation materials.

Microstructure and properties of high-strength lightweight ceramsites customised with ultra-fine copper tailings

The accumulation of copper tailings not only consumes a significant amount of land resources but also incurs substantial treatment expenses and causes environmental pollution. This article presents an investigation on the feasibility of utilizing ultra-fine copper tailings (CTs), polishing slag (PS), and fly ash (FA) to produce customised high-strength ceramsites for treating and reusing copper tailings.Additionally, the effects of raw material mass ratio and sintering temperature on the physical properties, thermal properties, chemical structure, and expansion mechanism of the high-strength ceramsites were investigated. The experimental results revealed that the well-formed ceramsites exhibited an apparent density of 486–2304 kg/m3, a bulk density of 288–1659 kg/m3, a 1-h water absorption rate of 0.13–3.9 %, and a particle compressive strength of 0.87–22.4 MPa with copper tailings content of 50∼100 % under preheating temperature 950 ℃ for 40 min and sintering temperature 1195–1225 ℃ for 40 min. The XRD analysis of crystal phases indicated that the mineral compositions of ceramsites contained quartz, anorthite, albite, and mullite. Moreover, the FTIR spectra displayed that [AlO4] and [SiO4] were interconnected into a complementary network which enhanced the strength of ceramsites. Additionally, the microstructure analysis revealed that more evenly distributed and smaller pore structures and rougher matrix were associated with higher compressive strength. The temperature difference between the interior and exterior led to the preferential formation of a slag phase which exerted a bonding effect on the composite feldspar phase. These findings suggest that ultra-finecopper tailings could be recycled in artificial aggregate technology in concrete engineering, and provide theoretical support for the large-scale utilization of tailings.

Effect of Various Sintering Temperatures on the Friction and Mechanical Properties of PEEK/PTFE Blends

Polytetrafluoroethylene (PTFE) has a very low coefficient of friction and outstanding corrosion resistance, but its limited use is due to high wear and tear and low hardness. Polyetheretherketone (PEEK) offers low wear, high temperature resistance and a slightly higher coefficient of friction. In the research we describe here we examined the mechanical and tribological properties of PEEK/PTFE blends manufactured at various sintering temperatures (350 °C–390 °C). The experimental data demonstrated that the PEEK/PTFE blends exhibited the highest tensile strength, 22.97 Mpa, when sintered at 380 °C, making them the most resistant to breaking or deforming. The elongation at break increased with the increase of sintering temperature, and the highest value of elongation at break for the PEEK/PTFE blends was 429.16% when sintered at 390 °C, and the lowest value was 283.37% when sintered at 350 °C. The PEEK/PTFE blends exhibited the lowest coefficient of friction, measuring 0.174, when sintered at 350 °C. The lowest mass abrasion rate for the PEEK/PTFE blends was 6.04 × 10−7 mm3/N·m when sintered at 360 °C.

Fabrication of High Thermal Conductivity Aluminum Nitride Ceramics via Digital Light Processing 3D Printing.

The sintering of high-performance ceramics with complex shapes at low temperatures has a significant impact on the future application of ceramics. A joint process of digital light processing (DLP) 3D printing technology and a nitrogen-gas pressure-assisted sintering method were proposed to fabricate AlN ceramics in the present work. Printing parameters, including exposure energy and time, were optimized for the shaping of green bodies. The effects of sintering temperature, as well as nitrogen pressure, on the microstructure, density, and thermal conductivity of AlN ceramics were systematically discussed. A high thermal conductivity of 168 W·m-1·K-1 was achieved by sintering and holding at a significantly reduced temperature of 1720 °C with the assistance of a 0.6 MPa nitrogen-gas pressure. Further, a large-sized AlN ceramic plate and a heat sink with an internal mini-channel structure were designed and successfully fabricated by using the optimized printing and sintering parameters proposed in this study. The heat transfer performance of the ceramic heat sink was evaluated by infrared thermal imaging, showing excellent cooling abilities, which provides new opportunities for the development of ceramic heat dissipation modules with complex geometries and superior thermal management properties.

Thermal Conductivity and Sintering Mechanism of Aluminum/Diamond Composites Prepared by DC-Assisted Fast Hot-Pressing Sintering.

A novel DC-assisted fast hot-pressing (FHP) powder sintering technique was utilized to prepare Al/Diamond composites. Three series of orthogonal experiments were designed and conducted to explore the effects of sintering temperature, sintering pressure, and holding time on the thermal conductivity (TC) and sintering mechanism of an Al-50Diamond composite. Improper sintering temperatures dramatically degraded the TC, as relatively low temperatures (≤520 °C) led to the retention of a large number of pores, while higher temperatures (≥600 °C) caused unavoidable debonding cracks. Excessive pressure (≥100 MPa) induced lattice distortion and the accumulation of dislocations, whereas a prolonged holding time (≥20 min) would most likely cause the Al phase to aggregate into clusters due to surface tension. The optimal process parameters for the preparation of Al-50diamond composites by the FHP method were 560 °C-80 MPa-10 min, corresponding to a density and TC of 3.09 g cm-3 and 527.8 W m-1 K-1, respectively. Structural defects such as pores, dislocations, debonding cracks, and agglomerations within the composite strongly enhance the interfacial thermal resistance (ITR), thereby deteriorating TC performance. Considering the ITR of the binary solid-phase composite, the Hasselman-Johnson model can more accurately predict the TC of Al-50diamond composites for FHP technology under an optimal process with a 3.4% error rate (509.6 W m-1 K-1 to 527.8 W m-1 K-1). The theoretical thermal conductivity of the binary composites estimated by data modeling (Hasselman-Johnson Model, etc.) matches well with the actual thermal conductivity of the sintered samples using the FHP method.

Sintering Driven Void Formation in PS@WO3 Core-Shell Composites: A Photodegradation Enhancement Strategy

Background: Polystyrene nanospheres are used as a substrate for the hydrothermal coating of tungsten trioxide (WO3) to form a core-shell composite of PS@WO3. The core-shell structure is used for the next sintering step. This produces porous WO3. The focus of this study is on the role of porous WO3 in enhancing photocatalytic performance. Methods: The hydrothermal method was employed for coating, and the surface morphology, as well as the structural properties of WO3-coated PS spheres, were systematically investigated using SEM and XRD analyses. Additionally, the sintering process was introduced to enhance the material by inducing rupture in the PS sphere core, creating voids that significantly increased the material's surface area. objective: The primary objective is to elucidate the correlation between sintering temperatures, crystallographic structures, and the resulting degradation efficiency of WO3-coated PS spheres. Specific attention is given to the role of hexagonal and orthorhombic structures and their impact on photocatalytic performance. Results: The evaluation of the effect of sintering temperature on photodegradation efficiency highlighted the crucial role of sintering temperature. Un-sintered and 300°C sintered WO3, both having a hexagonal crystalline structure, exhibited superior degradation efficiencies compared to samples sintered at higher temperatures (400°C and 500°C). In particular, the 300°C sintered WO3 outperformed its un-sintered counterpart despite identical crystalline structures. The performance of the PS@WO3 composite was assessed to determine the enhanced role of porous WO3. The porous WO3 obtained, in particular by the sintering of the core-shell PS@WO3 composites at 300°C, showed a remarkable improvement in the degradation efficiency. These composite demonstrated over 95% efficiency within 10 minutes and achieved near complete (100%) degradation for a further 10 minutes, surpassing the performance of pure WO3. It is important to clarify that while the final product was predominantly WO3 after the sintering process, the inclusion of PS served a critical purpose in creating voids during sintering. The PS@WO3 composite structure used as a resource for the preparation of porous WO3, even with a potentially reduced PS composition, has been found to play a significant role in influencing the surface area of the material, and consequently the photocatalytic performance. Conclusion: The study has highlighted the importance of crystalline structure and sintering conditions in optimizing the efficiency of photocatalytic materials. The porous WO3 obtained, in particular by the sintering of the core-shell PS@WO3 composites at 300°C, showed promising potential for applications under UV and visible LED light irradiation. These results provide valuable insights for the development of advanced photocatalytic materials with improved performance, highlighting WO3 as the key contributor to the observed improvements.

Synthesis, microstructure, properties of nonstoichiometry high entropy carbide (MoNbTaTiW)C4.5

AbstractA dense, fine‐grained, and toughened nonstoichiometry high entropy carbide (HEC) (MoNbTaTiW)C4.5 was synthesized via a two‐step way of carbothermal reduction‐solid solution using metal oxides and carbon. The effects of carbothermal reduction temperature, sintering temperature, and carbon content on the phase, microstructure, mechanical and thermal properties of (MoNbTaTiW)C4.5 were studied. The results showed dense and single phase (MoNbTaTiW)C4.5 were synthesized through reduction of metal oxides at 1600°C and sintered at and above 1950°C by spark plasma sintering. Reduced carbon content and higher solid solution temperature were beneficial to obtain dense HECs with better mechanical properties. With a carbon content of 90%, a reduction temperature of 1600°C, a holding time of 20 min, and a sintering temperature of 1950°C, the as‐synthesized (MoNbTaTiW)C4.5 showed a higher fracture toughness (5.2 MPa·m1/2). Besides, the (MoNbTaTiW)C4.5 showed a low thermal conductivity (5.9 W/m·K, at room temperature).

Examining the effects of sintering temperature on double perovskite La2NiTiO6: Analysis of structural, optical, electrical properties, and leakage current characteristics

This study explores the influence of varying sintering temperatures on the structural, optical, electrical, and leakage current features of La2NiTiO6 (LNTO), a double perovskite material synthesized through the citrate auto-ignition method. The X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray (EDX) analysis were employed to investigate the structure, microstructure, and compositional distribution of the samples. The samples sintered at various temperatures showed the monoclinic structure with space group P21/n and were confirmed by Rietveld's refinement of the XRD patterns. The average grain size increased with higher sintering temperatures, which is consistent with the particle size estimated from the histogram plot of the FE-SEM data. The UV–visible (UV–Vis) spectroscopy showed that the energy band gap decreased as sintering temperatures increased. Impedance spectroscopy analysis revealed non-Debye type relaxation of charge carriers and confirmed the negative temperature coefficient of resistance (NTCR) behavior. Electrical analysis affirmed that the direct current (DC) conductivity is thermally activated, following the Arrhenius equation with an inverse temperature dependency. As the sintering temperature increases, the leakage current density decreases, and the leakage current conforms to the ohmic conduction mechanism.

The effects of sintering temperature on the microstructural evolution and mechanical properties of yttrium hydride monoliths via spark plasma sintering

In recent years, yttrium hydride has garnered significant attention due to its remarkable thermal stability and potential for high hydrogen density. It is regarded as one of the most promising metal hydrides for use as a neutron moderator in microreactors. In this study, yttrium hydride monoliths were synthesized using yttrium hydride powder obtained through direct hydrogenation, facilitated by Spark Plasma Sintering (SPS) at temperatures ranging from 800 to 1200 ℃. The effects of SPS temperatures on the phase composition, microstructure, density, and mechanical properties of yttrium hydride monoliths were studied. The results show that the sintering temperature markedly impacts the hardness, pore evolution, grain size and precipitation of α-Y and Y2O3 phase. Notably, the hardness of the samples escalates significantly with an increase in sintering temperature below 1000 ℃, influenced by a reduction in both the number and size of pores. The occurrence of twin crystals, distribution of grain size and the phase-transformed particles of α-Y within the sintered sample may contribute to an increase in hardness. The procedures described herein affect developing important microstructure-property relationships, as well as correlations in the sintering parameters and mechanical properties.

Effect of sintering temperature and silicone resin content on in-situ formed SiC nanowire reinforced ceramic shells

The silicone resin was used to modify ceramic shells for investment casting. SiC nanowires were in-situ formed by the carbothermal reduction method. The pyrolysis of silicone resin and the formation mechanism of SiC nanowires were investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that the shells had the maximum sintering bending strength of 7.35MPa when the silicone resin content and the sintering temperature were 20wt% and 1300 °C, respectively. The phase of β-cristobalite during the transformation from amorphous SiOC to fused SiO2 after the pyrolysis of silicone resin impacted the bending strength. In addition, the iron oxide in corundum sand was used as the catalyst in the VLS mechanism to form the ball-stick-shaped SiC nanowires at 1000 °C-1100 °C. However, the necklace-like and rod-like SiC nanowires were formed at 1200 °C-1300 °C in the VS mechanism, which replaced the VLS mechanism.

Fabrication of high-permeance SiC filters reinforced with in situ-grown mullite whiskers for gas/solid filtration

The pursuit of cost-efficiency, superior strength, and excellent gas permeance has driven the development of silicon carbide (SiC) membranes or filters for gas/solid filtration. In this study, SiC filters with high gas permeance reinforced with in situ-grown mullite whiskers were successfully prepared through reaction bonding. Low-cost kaolin and bauxite were used as sintering aids and raw materials for mullite whisker formation, and MoO3 was used as an additive to promote mullite whisker growth. The effects of different sintering temperatures and the addition of kaolin, bauxite, and MoO3 on filter performance were systematically investigated. When the sintering aid and MoO3 content additions were 6 and 1.5 wt%, respectively, and the sintering temperature was 1450 °C, the resulting ceramic filter exhibited a porosity of 45.5 %, a bending strength of 17.9 MPa, and an average pore size of 47.7 µm. Moreover, the filter exhibited a high Darcy’s permeability coefficient of 2.42 × 10−11 m2, satisfactory chemical stability, and thermal shock resistance. The addition of MoO3 facilitated the consumption of the molten phases and increased the anisotropic growth rate of the mullite whiskers, which contributed to the fabrication of the high-permeance filters. Finally, the ceramic filters demonstrated good performance for the filtration of dusty gases loaded with fly ash particles with a mean size of 15.3 µm at room temperature and 300 °C, and the removal rate reached > 99.9 %. The pressure drop was a little lower than that of our commercially available SiC filters. The SiC filters showed good prospects in the field of gas/solid filtration.

Fabrication, microstructure, and mechanical properties of novel three‐layer structured bionic ceramic cutting tools

AbstractCeramic cutting tools have low fracture toughness owing to brittleness. To improve the fracture toughness and flexural strength of ceramic cutting tools, the growth model of SiCw during the sintering process was established by the laminated structure and anisotropy of growth of bionic shells. Furthermore, a theoretical model of sintering parameters and total fracture toughness was achieved. Then, the dispersion process of SiCw was improved to enhance the homogeneity of the mixed powders further. Finally, a novel three‐layer structured bionic ceramic cutting tool was fabricated by hot‐pressing. The effects of sintering temperature, holding time, and sintering pressure on the mechanical properties and microstructure of bionic ceramic cutting tools were investigated. The results showed that the flexural strength (three point bending), fracture toughness (indentation method), and Vickers hardness of the three‐layer structured bionic ceramic cutting tool with excellent dispersed were 735 ± 34 MPa, 5.68 ± 0.06 MPa·m1/2, and 19.66 ± 0.12 GPa, respectively. The microstructure of the fracture revealed that the fracture mechanism of the bionic ceramic cutting tool was a mixture of intergranular fracture, transgranular fracture, whisker pull‐out, whisker fracture, forked crack, crack deflection, crack bridging, zig‐zag crack, and crack termination. The accuracy of the total fracture toughness model was reliable.

Low temperature fabrication of highly dense α‐Si3N4 ceramics

AbstractHighly dense α‐silicon nitride (Si3N4) ceramics were densified at a lower temperature of 1450°C under a moderate mechanical pressure of 50 MPa from commercial α‐Si3N4 powder and with conventional Al2O3–Y2O3 sintering additives. The fabricated α‐Si3N4 ceramics exhibited a hardness of 19 GPa, which is higher than that of the β‐Si3N4 ceramics usually obtained. The effect of sintering temperature and sintering pressure in the liquid phase sintering of the α‐Si3N4 ceramics is studied. The role of the dissolution–reprecipitation process and the particle rearrangement during densification of the α‐Si3N4 ceramics is discussed.

Effects of sintering temperature on the microstructure evolution and mechanical properties of TiB2-20 wt% CoNi cermets

Microstructure evolution and mechanical properties of TiB2-CoNi cermets at different sintering temperatures were investigated. A small amount of liquid phase appeared between 1362 ºC and 1398 ºC. Solid phase sintering mainly occurred below this temperature range, while liquid phase sintering mainly occurred above this temperature range. At around 1460 ºC, dissolution and re-precipitation occurred around TiB2 particles due to liquid phase migration. Only TiB2 and CoNi phases were detected on XRD patterns at different sintering temperatures. As the sintering temperature increased, the relative density, fracture toughness, transverse fracture strength, and hardness of cermets increased, while their porosity decreased. The main influencing factors on the properties of cermets sintered at 1460 ºC and above were the interface bonding strength and the grain size, while the porosity was the main influencing factor for cermets sintered below 1460 ºC.

Preparation of high performance porous SiC ceramic membrane support using zeolite and alumina as sintering additives

In-situ reaction bonded porous SiC ceramic membrane supports were successfully synthesized by economical way at 1300 °C in air using waste zeolite residue and alumina as sintering additive. The effects of additives content and sintering temperature on material, mechanical and permeabity properties were carefully investigated. The ceramics prepared at 1300 °C with a 20 % mixture of zeolite residue and alumina obtained with a very high mechanical strength of 114.85 MPa at a porosity of 28.90 vol% and exhibited pure water permeability of 1258 L.h-1.m-2.bar−1. Additionally, the support prepared in this study exhibited good chemical resistance in acid and alkali medium for long periods.The utilization of zeolite residue reduced the sintering temperature for fabrication of membrane support and provided a flexible strategy to control the mechanical performance and water permeability. The filtration and permeation results indicated that SiC membrane support prepared in this study is suitable for various applications, particularly in water treatment.

Effects of sintering parameters on the preparation and properties of foamed ceramics from cyanide tailings

ABSTRACT In this study, foamed ceramics were successfully prepared using cyanide tailings (CTs) with a high sulfur content as the main raw material. The effects of sintering temperature, holding time, and heating rate on the bulk density, water absorption, porosity, pore structure, and compressive strength of foamed ceramics were systematically investigated. The results showed that the elevated sintering temperature promoted the generation of liquid phases, resulting in an obvious enlargement of the pore size and a decrease in bulk density. In addition, a similar evolution trend could be found in the pore size and bulk density with the extension of the holding time, which was attributed to the degrees of silicon carbide reaction. Foamed ceramics with small pore sizes could be prepared at a heating rate that did not exceed 4°C/min. Then, the higher heating rates could bring abnormally large pores and be detrimental to the mechanical properties of the foamed ceramics, which were proven to be related to the decomposition of FeS2 introduced by CTs during the heating process. In conclusion, the foamed ceramics prepared with CTs in this study provide effective solid waste utilization and have good application prospects in wall composite one-piece insulation panels.