Effect Of Sintering Temperature Research Articles

An in-Depth Analysis on the Cumulative Effect of Co and Sintering Temperatures on the Formaldehyde Sensing Attributes of NiO

An in-Depth Analysis on the Cumulative Effect of Co and Sintering Temperatures on the Formaldehyde Sensing Attributes of NiO

Effects of sintering temperature on the physical, structural, mechanical and antimicrobial properties of extracted hydroxyapatite ceramics from Anabas testudineus bone and head scull for biomedical applications

In this experimental investigation, Hydroxyapatite (HAp) is extracted from bone and head scull of Anabas testudineus by thermal calcination at 800 °C for 5 h under ambient air conditions. Ceramic samples were prepared through compaction and followed by sintering at 1200 °C, 1250 °C, and 1300 °C temperatures for 2 h from the calcined HAp powder. Both the calcined powder and sintered ceramic samples were characterized using X-ray Diffraction (XRD), Energy dispersive X-ray spectroscopy (EDS) and Scanning Electron Microscopy (SEM) to explore the potentiality of the extracted ceramics for biomedical applications. Moreover, the elemental composition, phase structure, compressive strength, Vicker hardness, and antimicrobial characteristics of the ceramic samples have been investigated. The XRD analysis confirmed the presence of hydroxyapatite in both the calcined powder and ceramic samples. Various types of trace elements were observed in HAp ceramics including a noteworthy 1.57 atomic percent of magnesium (Mg). Additionally, the XRD spectrum indicated the existence of the β-tricalcium phosphate (TCP) phase. Upon sintering at a temperature of 1250 °C, the ceramic sample underwent a phase shift to α-TCP. Our results show that the phase transition has a significant effect on the crystallinity of HAp. The ceramics sample sintered at 1300 °C exhibited the highest compressive strength and Vicker Hardness due to its high relative density, well-packed grains, and larger particle size. The sintered sample did not exhibit notable zone of inhibition against Escherichia coli and Staphylococcus aureus bacteria.

Effect of Sintering Temperature on the Microstructure and Mechanical Properties of Nanocrystalline Cemented Carbide

Effect of Sintering Temperature on the Microstructure and Mechanical Properties of Nanocrystalline Cemented Carbide

Effect of hybrid ratio and sintering temperature on hardness properties of hybrid AMCs

The present research work is aimed toward fabrication of hybrid Aluminium matrix composites (AMCs) of different hybrid ratios of Alumina (Al2O3) and Silicon Carbide (SiC) followed by investigation of their microstructure and hardness properties. Hybrid AMCs were fabricated through powder metallurgy process by adding 5 wt% and 10 wt% mixture of Al2O3 and SiC reinforcements of various hybrid ratios (0:1, 1:3, 1:2, 1:1, 3:1, 2:1 and 1:0) with the pure Aluminium powder. The mixture powder were properly mixed by ball milling arrangements for 6 h. The mixture powder were preheated at 500 °C for 2 h in a high temperature programmable tube furnace followed by immediate compaction under a closed die at 1500 psi pressure through automatic hydraulic press. The compacted specimens were then sintered at 350 °C, 500 °C and 650 °C for 2 h in the same furnace. Hardness test of the fabricated hybrid AMCs were carried out by Vickers Micro-hardness testers and hardness values were measured by the integrated software. The hardness properties of hybrid AMCs also were compared with the hardness properties of pure Aluminium specimens fabricated through the same process route and process parameters. It is interestingly observed that hardness of hybrid AMC is more when pure Aluminium powder is reinforced with only SiC of same wt.% for both the cases (5 wt% and 10 wt% reinforce AMCs) and it decreases with decrease of weight fraction of SiC and simultaneously increase of weight fraction of Al2O3 keeping total weight fraction of mixture as constant.

Effect of cell sintering temperature on the performance of non-noble metal loaded cerium oxide SOEC anodes

Abstract Introducing methane oxidation reaction into the anode of the high-temperature solid oxide electrolysis cell (SOEC) can reduce the power consumption for water electrolysis. Compared to the traditional conditions of methane oxidation, the methane oxidation catalyst sintered at the SOEC anode, which is closely related to the cell sintering process. This study uses non-noble metals as active sites for methane oxidation, zirconia, and samarium oxides doped ceria as catalyst support and oxygen ion conductors. The effects of anode sintering temperature on the electrochemical performance of SOEC assisted by methane oxidation were investigated. The results indicate that the high-temperature sintering process promotes the performance of the SOEC anode with Ni as the active site, while high temperature harms the performance of the Co-loaded anode. The sintering temperature exhibits a poor effect on the Fe-loaded anode. The Ni exhibits good enhancement of methane oxidation on reducing the electrolysis voltage of SOEC, while Co only exhibits methane oxidation assistance at low-temperature sintering. Differently, Fe has almost no obvious methane oxidation assistance for SOEC, which mainly represents good oxygen evolution performance.

Microstructure and properties of tungsten‐40 wt.–% copper composites fabricated by binder jet 3D printing

AbstractIn this work, the tungsten‐copper composites were fabricated by binder jet 3D printing technology. The effects of different printing layer thicknesses (50 μm to 100 μm) on the green density and green strength were investigated. Then, under the optimal layer thickness, the effects of different sintering temperatures (1300 °C to 1600 °C) on the microstructure and densification of tungsten‐40 wt.–% copper composites were studied. The experimental results showed that when the printing layer thickness was set as a lower value (50 μm), the tungsten‐40 wt.–% copper green part had the best strength and its density reached a maximum value of 60.73 %. After sintering for green parts printed with 50 μm layer thickness, the relative density, thermal conductivity and electrical conductivity of sintered parts first increased and then decreased with increasing sintering temperature. In our experiments, the tungsten‐40 wt.–% copper sample fabricated by binder jet 3D printing with a printing layer thickness of 50 μm under a sintering temperature of 1500 °C displayed the best properties, in which the relative density, thermal conductivity and electrical conductivity were 97.04 %, 228 W⋅m−1⋅K−1 and 46.5 % IACS, respectively.

Effect of sintering temperature on ratcheting-fatigue behavior of nanosilver sintered lap shear joint

Purpose The paper aims to study the effect of sintering temperature on the microstructure, shear strength and ratcheting fatigue life of nanosilver sintered lap shear joint. In addition, the Gerber model is used to predict the ratcheting fatigue lives of nanosilver sintered lap shear joints at different sintering temperatures. Design/methodology/approach In this paper, the nanosilver sintered lap shear joints were prepared at three sintering temperatures of 250 °C, 280 °C and 310 °C. The bonding quality was characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscope and shear tests, and the long-term reliability was studied by conducting ratcheting fatigue tests. In addition, three modified models based on Basquin equation were used to predict the ratcheting fatigue life of nanosilver sintered lap shear joint and their accuracies were evaluated. Findings When the sintering temperature is 250°C, the nanosilver sintered lap shear joint shows the porosity of 22.9 ± 1.6 %, and the shear strength of 22.3 ± 2.4 MPa. Raising the sintering temperature enhances silver crystallite size, strengthens sintering necks, thus improves shear strength and ratcheting fatigue life in joints. In addition, the ratcheting fatigue lives of the joints sintered at different temperatures are effectively predicted by three equivalent force models, and the Gerber model shows the highest life prediction accuracy. Research limitations/implications The sintered silver bondline is suffering a complex stress state. The study only takes the shear stress into consideration. The tensile stress and the combination of shear stress and tensile stress can to be considered in the future study. Practical implications The paper provides the experimental and theoretical support for robust bonding and long-term reliability of sintered silver structure. Social implications The introduced model can predict the ratcheting fatigue lives of the joints sintered at different temperatures, which shows a potential in engineering applications. Originality/value The study revealed the relationship between the sintering temperature and the microstructure, the shear strength and the ratcheting fatigue life of the joint. In addition, the Gerber model can predict the ratcheting fatigue life accurately at different sintering temperatures.

Effects of sintering temperature on the microstructure and mechanical properties of Ni-based alloy

Ni-based alloys were prepared at different sintering temperatures in this study. The effects of sintering temperature on the volume fraction, morphology, and distribution of precipitates in Ni-based alloys, and its impact on mechanical properties were studied. The results show that the microstructure contains γ-Ni, Ni3Si, M7(B, C)3, M23(B, C)6, and a Si-rich multi element phase. The morphology of M7(B, C)3 particles undergoes an evolution of small particles → mainly strip shape → mainly small block shape and nearly spherical shape, accompanying with the dissolution-reprecipitation process of M7(B, C)3 particles caused by the diffusion of Cr element with the increasing of sintering temperature. Meanwhile, the M23(B, C)6 particle is keeping aggregating and growing. The relative density, microhardness, and bending strength of Ni-based alloys also increase. Especially these properties are found to be increase quickly between 1025 °C and 1050 °C. The increase in microhardness and bending strength is attributed to the reduction in the number of residual sintering pores and the increase in the volume fraction and size of precipitates. In addition, the transition of fracture morphology from intergranular fracture mode to a combination of intergranular and partially transgranular fracture mode also contributes to the rise in bending strength.

Effect of sintering temperature on microstructure and properties of Cu/graphite composites hybridized with MoAlB ceramic particles

Using a fast hot press sintering technique, Cu/graphite composites doped with MoAlB ceramic particles were synthesized. The impact of varying sintering temperatures on the composites' mechanical, tribological, and microstructure characteristics were studied. The Al element diffused from the MoAlB particles into the copper matrix and produced the MoB phase when the sintering temperature rose over 850 °C. The formation of MoB phase, which was well bound to the matrix, and the formation of Cu(Al) solid solution could improve the plastic deformation resistance of the composites. This, along with the lubrication supplied by graphite, synergistically improved the mechanical and frictional properties of Cu/graphite composites. The composites exhibited remarkable wear resistance (the wear rate was reduced to 3.36 × 10−5 mm3·N−1·m−1) and high compressive strength (266.25 MPa) when the sintering temperature was set to 900 °C. In order to create high-performance copper-based self-lubricating composites, this effort may offer a new research direction.

Effect of Sintering Temperature on the Residual Stress of SrO-MgO-SiO2 Glass-Ceramic Sealant for Solid Oxide Fuel Cells

Effect of Sintering Temperature on the Residual Stress of SrO-MgO-SiO2 Glass-Ceramic Sealant for Solid Oxide Fuel Cells

The Effect of Sintering Temperature on the Microstructure and Electrical Properties of ZnO–Bi2O3 Varistor Ceramics

The Effect of Sintering Temperature on the Microstructure and Electrical Properties of ZnO–Bi2O3 Varistor Ceramics

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.

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 20 wt%, porous CA6 ceramics with well cross-interlocking plate-like structures, possessing low thermal conductivity of 0.32 W·(m·K)−1 (1000°C), high apparent porosity of 68.28%, and desirable compressive strength of 6.76 MPa, 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.

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.

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.

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-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 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.