Varying Sintering Temperature Research Articles

Crystallite size and phase purity in Pb1-xSrxTiO3 ferroelectric perovskites for biomedical applications via controlled sintering

ABSTRACT Lead strontium titanate (Pb1-xSrx)TiO3 (PST) is a ferroelectric perovskite material with tunable properties, including Curie temperature, spontaneous polarization, and high dielectric permittivity, making it promising for advanced biomedical applications, such as biosensors, bioimaging, and light-activated therapeutics. This study investigates the effect of varying sintering temperatures on the crystallite size and phase purity of PST, aiming to optimize its performance for biomedical devices. PbCO3, SrCO3, and TiO2 powders were processed via ball milling for 58 hours, followed by sintering at temperatures ranging from 500°C to 1100°C. Laser diffraction particle size analysis and X-ray diffraction (XRD) were used to assess the particle size and crystal phase transformations. The results demonstrate that higher sintering temperatures improve the PST phase composition, reducing impurities and enhancing crystallite growth. The most significant crystal growth was observed at 900°C, while the optimal phase purity and crystallite size (91.5 nm) were achieved at 1100°C, producing 100% single-phase PST. These findings emphasize the critical role of sintering temperature in tailoring PST’s properties, enhancing its suitability for electronic and microelectronic biomedical devices. Controlled sintering in perovskite materials opens new pathways for their application in medical diagnostics and therapeutic technologies.

Effects of sintering temperature on microstructure and varistor performances of ZnO-SrCO3-Co2O3 ceramics

Sintering temperature is decisive for optimizing the grain boundary environment to obtain the high performance ZnO based varistor ceramic. In this work, the impacts of sintering temperature on microstructure and electrical properties of ternary Zn-Sr-Co varistor were investigated. It was found that the distribution of Sr, the critical factor to form grain boundary, was heavily sensitive to sintering temperature. The considerable Sr ions precipitated at grain boundaries and formed the clusters of SrZnO2 while the sintering temperature increases from 1150 °C to 1190 °C. Besides, the precipitation of Sr led to the large segregation of Co at grain boundaries. The enrichment behavior of Sr and Co contributed to the optimization of grain boundaries, resulting in the enhanced barrier height. As a result, the excellent nonlinear current-voltage performances, i.e., the high nonlinear coefficient of 56.47 and the low leakage current density of 0.73 μA/cm2 were obtained in the ternary ZnO-SrCO3-Co2O3 varistor sintered at 1190 °C. However, the grain boundary environment would be destroyed by the excessive temperature of 1210 °C, resulting in the degradation of grain boundary barrier and especially a surge in the leakage current IL from 0.73 to 92.19 μA/cm2. In addition, varying sintering temperature has the important effects on impedance and dielectric properties of the ZnO-SrCO3-Co2O3 varistors. The findings provide new perspectives for developing the high-performance ternary ZnO-SrCO3-Co2O3 varistor ceramics by optimizing the initial grain boundary environment at different sintering temperatures.

Self-generated B-MAX phase composites: The effect of sintering temperature on surface morphology and phase composition

The use of metal-based MAX phase composites is widespread in the production of high-temperature structural materials, anticorrosive materials and electrode materials. Herein, novel B-Ti3AlC2 and B-Ti4AlN3 composites were prepared using the hot-pressing method at varying sintering temperatures ranging from 950 °C to 1325 °C. This study also explores the effect of sintering temperature on the surface morphology and phase composition of both B-MAX phase composites. The morphological and crystal phase composition of MAX phase composites were investigated through SEM coupled with EDS, FE-SEM, AFM, and XRD test analysis. The results revealed that higher sintering temperatures increase the clear formation of MAX phases and composites as compared to lower temperatures. The findings also expose that the in-situ formation of B-MAX composites significantly changes the structure, contributing to transforming the overall performance and making it suitable for high-stress applications like electronics, aerospace, and cutting tools.

Synthesis, Structure and Luminescence Properties of Mn-doped MgAl2O4 Red-Emitting Phosphors with Varying Sintering Temperature.

Oxide matrix red-emitting phosphors are deemed as excellent color converters for white light emitting diodes (WLEDs) and laser diodes (LDs). Manganese-doped MgAl2O4 powder was synthesized by a solid-state reaction method at different sintering temperatures. Microstructure shows that grain size is mainly in the range of 0.2-5μm, and grain agglomeration occurs with increased sintering temperature. XPS analysis indicates that the doped Mn ion exhibits a valence state of + 4 within the MgAl2O4 matrix. The diffraction peak of the phosphors is shifted by the sintering temperature, which affects lattice constant. Upon excitation by 300nm ultraviolet light, the samples emit asymmetric broadband red light within the range of 620-720nm, attributed to Mn4+ ion's transition from 2Eg to 4A2g states. With the increasing temperature, the main emission peak shifts from 677nm to 650nm, ascribed to the change in energy level (2Eg) resulting from the reduction of Al2O3 phase. Crystal field theory confirmed that Mn4+ ions are within a strong crystal field environment created by MgAl2O4 matrix. By affecting particle size and crystallinity, the sintering temperature influences the fluorescence lifetime of the Mn4+ ion. Notably, these red-emitting phosphors exhibits remarkable thermal stability as their emission intensity remains approximately at 58% of initial intensity even at elevated temperature (435K). Consequently, Mn4+: MgAl2O4 red-emitting phosphors with high thermal stability render them promising candidates for WLED applications.

Modeling acoustic characteristics of artificial bone alloys for medical and surgical use under thermodynamic conditions

The study examines the impact of porosity on mechanical, acoustic, and behavioral properties of (Ti-6Al-4 V alloy) alloys, which are manufactured to mimic human bones. It investigates how porosity, controlled through factors like pressure, particle size, and temperature during sintering, affects properties such as modulus of elasticity, surface acoustic wave (SAW) velocities, hardness coefficients, and acoustic resistance.The findings suggest that different levels of porosity at varying sintering temperatures significantly alter the dynamic elastic modulus of the alloys. Specifically, increasing porosity values seem to correlate with a decrease in elastic constants, elastic modulus values, and surface acoustic wave types. This phenomenon may be attributed to the transitional crystalline structure phases of Ti6Al4V alloy and the manufacturing process.Remarkably, the study concludes that these (Ti-6Al-4 V alloy) alloys exhibit superior porosity, mechanical, and acoustic qualities compared to various types of human bone, including cortical, trabecular, and cancellous bone.

A Study on Microstructural Evolution and Corrosion Behavior of Ti36-Al16-V16-Fe16-Cr16 High-Entropy Alloy Fabricated via Spark Plasma Sintering Technology

This study focused on the synthesis of Ti36-Al16-V16-Fe16-Cr16 high-entropy alloys (HEAs) through spark plasma sintering to ascertain their corrosion resistance performance. Varied sintering temperatures, ranging from 700 to 1100 °C were employed to discern their impact on the alloy's characteristics. The fabricated HEAs underwent characterization using scanning electron microscopy and X-ray diffraction. A potentiodynamic polarization measurement was employed to compare the electrochemical properties of HEAs sintered at different temperatures in sulfuric and chloride aggressive media. The study outcomes indicate that the HEA sintered at 1000 °C exhibited superior corrosion resistance compared to other HEAs at other temperatures. This study contributes valuable insights into the nuanced relationship between sintering temperature, microstructure, and corrosion resistance of Ti36-Al16-V16-Fe16-Cr16 HEAs.

Crystal structures, lattice vibrational characteristics, and dielectric responses of ZnWO4 microwave dielectric ceramics sintered at different temperatures

The study meticulously examined the impact of varying sintering temperatures on the phase transformations, crystallographic configurations, dielectric response mechanisms, and lattice vibrational characteristics of the ZnWO4 ceramics. Far-infrared reflectance spectra were fitted using a four-parameter semiquantum model to obtain the intrinsic dielectric properties. Moreover, the contribution to the dielectric properties for each vibrational mode was analyzed, indicating that the lower-frequency mode had the most contribution. The relationship linking the structural aspects to the properties of ZnWO4 ceramics was elucidated through an analysis of the Raman spectral modes across a range of sintering temperatures, overcoming the limitation of solely textual description without mathematical quantification. When sintered at 1070 °C, the ZnWO4 ceramic had the best dielectric properties: εr = 14.81, Q×f = 34,239 GHz (f = 9.69 GHz), with the highest relative density of 96.95 %.

Pulse current enhanced densification and mechanical property of Inconel 718 superalloy fabricated by spark plasma sintering

The Inconel 718 superalloy was fabricated using spark plasma sintering (SPS) technology with varying sintering temperatures and heating rates. The densification and mechanical property of the sintered superalloys were characterized through tensile and compression tests at room temperature, as well as microscopic analyses. The evidence suggests that the plasma generated between the particles results in evaporative melting on the particle surface and plastic deformation of the particle boundaries, accelerating the densification process is by 3∼4 times. Besides, the grain size refinement coefficient affected by pulse current in the holding stage is 0.7–0.8, leading to a significant grain boundary strengthening during SPS process. The dislocation dominated by ball milling and SPS parameters also helps improve the strength and plasticity of the sintered superalloy. The superalloy sintered at 1050 °C with a heating rate of 100 °C/min demonstrated the highest tensile and compressive fracture strengths, measuring 1410 MPa and 1983 MPa, respectively, with the tensile and compressive yield strength of 712 MPa and 1557 MPa, respectively. Lower sintering temperatures or higher heating rates results in lower levels of densification and decreased strength. In addition, plasticity is reduced at higher sintering temperatures or lower heating rates due to excessive precipitation of brittle phases.

Manufacture and characterization of alumina-silica fiber reinforced alumina-silica ceramic matrix composite and bolt with low thermal conductivity and high strength

As the service temperature of reusable launch vehicles increases, the issue of thermal short circuits in thermal protection system connectors becomes more critical. The current focus is on developing connector materials with low thermal conductivity and high strength. In this study, alumina-silica fiber reinforced alumina-silica ceramic matrix (ASf/AS) composite is fabricated using matrix design and mold-pressing process to achieve the desired properties. By investigating composite materials with bimodal particle size distribution and varying sintering temperatures, the filling efficiency of the matrix within fiber bundles is enhanced and matrix shrinkage during sintering is reduced. The ASf/AS composites achieve a flexural strength of 129.7 ± 5.8 MPa, a tensile strength of 86.1 ± 2.5 MPa, and exhibited low thermal conductivity of 0.415 W/(m·K). Subsequently, ASf/AS bolts are produced following specific design parameters. The strength and failure mechanism of the ASf/AS composites and bolts are examined based on micro-morphology and stress-strain curve analysis. This research offers a promising approach for developing low-thermal conductivity and high-strength connector composite materials for aerospace thermal protection systems.

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.

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.

PENGARUH VARIASI SUHU SINTERING ALUMUNIUM MATRIK YANG DIPERKUAT KARBON NANOTUBE TERHADAP NILAI KEKERASAN

This study examines the effect of sintering temperature variations on density values and Vickers hardness values on Aluminum Carbon Nanotubes. Tests were conducted using five temperature variations, namely sintering 400°C, 500°C, 600°C, 700°C, and unsintered. The results showed that the 400°C sintering temperature variation produced higher hardness values than the 500°C, 600°C, 700°C, and unsintered sintering temperature variations. AlCNT specimens at a sintering temperature of 400°C have an average hardness value of 46.92 VHN, while at a sintering temperature of 500°C have an average hardness value of 30.48 VHN, while at a sintering temperature of 600°C have an average hardness value of 29.04 VHN, while at a sintering temperature of 700°C have an average hardness value of 26.17 VHN, while at a sintering temperature of 0°C have an average hardness value of 39.79 VHN. Therefore, it is found that the best sintering temperature variation for AlCNT specimens is 400°C for the application of sintering to aluminum carbon nanotubes. In addition, this research can be a reference for further researchers in developing manufacturing methods and characterization of aluminum reinforced with carbon nanotubes to obtain optimal results.

Exploration of structural and dielectric properties of orthorhombic Ta2O5 nanoplatelets towards the potential optoelectronic devices

The dielectric characteristics of tantalum pentoxide (Ta2O5) nanostructures, synthesized by hydrothermal process, have been investigated in the temperature range of 80 K to 400 K and frequency range of 20 Hz to 2 MHz. X-ray diffraction (XRD) confirms the formation of highly crystalline and orthorhombic phase of the nanostructures sintered at 950 ºC. The electron microscope images reveal that the synthesized nanostructures change their morphology to nanoplatelets upon increasing the sintering temperature. Further, UV–visible absorbance, FTIR and Raman spectra of the synthesized nanostructures were obtained to investigate their optical properties. The experimentally obtained dielectric results indicate that both the dielectric constant (ε) and dielectric loss (D) values increase with increasing operating temperature. Also, the dielectric constant increases to 20 while the dielectric loss decreases to <0.025 at room temperature on increasing the sintering temperature. At 300 K and 1 kHz, the value of ε becomes almost twice that of as-synthesized nanostructures i.e. from 10 to 20 on increasing the sintering temperature to 950 ºC. The enhancement in dielectric constant can be justified by the thermally activated orientational and interfacial polarization associated with the increase in the grain size of the Ta2O5 nanoplatelets at higher sintering temperatures. Furthermore, the frequency dependence of ε indicates the high effect of the distribution of relaxation time in the Ta2O5 nanoplatelets at lower frequencies. Overall, this study provides a better understanding of the structural and dielectric behaviour of Ta2O5 nanostructures in correlation with varying sintering temperature. The results suggest that the orthorhombic Ta2O5 nanoplatelets have potential applications as alternative dielectric materials in various electronic and optoelectronic devices.

Piezoelectric properties of PMN-PNN-PZT ceramics for the application ultrasonic device of ultrasonic tooth cleaner

In this study, PMN-PNN-PZT ceramics were fabricated with the variation of sintering temperature from 900 °C to 960 °C for the application ultrasonic device of ultrasonic tooth cleaner. Their piezoelectric and dielectric properties were investigated according to changes in sintering temperature. The temperature with the best piezoelectric properties was 920 °C. The excellent values of dielectric constant = 1552, density= 7.77 g/cm3, kp = 0.61, d31 = 117[pC/N], Qm =802 were obtained, respectively. These values were suitable for the application of ultrasonic device.

Effect of sintering temperatures on the physical, structural properties and microstructure of mullite-based ceramics

&lt;abstract&gt; &lt;p&gt;This study explored the impact of sintering temperature variations on the synthesis and characteristics of mullite ceramics derived from a composite blend of kaolinite clay, silica (silicon dioxide), and feldspar. Sintering temperatures ranging from 1100 to 1200 ℃ were systematically examined to analyze alterations in shrinkage, density, microstructure, elemental composition, and phase formation. The study revealed that an increase in sintering temperature led to decreased shrinkage due to improved particle packing and reduced porosity. Ceramic density showed a direct relation with sintering temperature, reaching the optimal density at 1175 ℃ and indicating efficient particle packing and compaction. Analysis through field emission scanning electron microscopy (FESEM) provided insights into microstructural changes, including alterations in grain morphology, porosity, and connectivity. Energy dispersive X-ray spectroscopy (EDS) clarified element distribution within the microstructure, offering valuable information on compositional variations. X-ray diffraction (XRD) examinations unveiled temperature-dependent phase transformations, which confirmed the successful formation of mullite during the sintering process. A sintering temperature of 1175 ℃ yielded the optimal ceramic quality and cost-effectiveness for high-temperature heating processes.&lt;/p&gt; &lt;/abstract&gt;

Pengamatan morfologi β-tcp yang disintesis dari cangkang kerang hijau

β-Tricalcium Phosphate (β-TCP) is a biomaterial commonly used in dentistry as a bone substitute. β-TCP is a calcium phosphate compound where β-TCP requires a calcium source to be synthesized. The source of calcium could be obtained from green mussel shells because they have high calcium carbonate (CaCO3). The purpose of this study was to determine the effect of sintering temperature on the morphology of β-TCP synthesized from green mussel shells. The method of this research is an exploratory research conducted by knowing the effect of sintering temperature on the morphology of β-TCP synthesized from green mussel shells. The results of the synthesis were tested for characterized with a Scanning Electron Microscope (SEM). In the SEM characterization results, the higher the sintering temperature used in the sample, the more fused and resulting larger particle size. β-TCP with sintering temperature variations of 950℃, 1.000℃, 1.050℃ and 1.100℃ has a morphology consisting of small particles of irregular shape and bonding to each other to form micropores. The conclusion in this study is that the higher the sintering temperature applied, the more the particles coalesce and form larger particles.

VARIATION OF SINTERING TEMPERATURE IN THE SYNTHESIS OF FLUORAPATITE FROM SNAIL SHELLS (Achatina fulica) USING THE SOL-GEL METHOD

Dental caries can cause porous cavities and even broken teeth, necessitating natural teeth extraction and replacement with implants. Fluorapatite, a dental implant material, can be synthesized from snail shells containing 98% calcium carbonate. This study aims to identify the characteristics of fluorapatite and determine the effect of variations in sintering temperature on the synthesis of fluorapatite made from snail shells using the sol-gel method. Variations of sintering temperature used are 700, 900, and 1100 °C. The results showed that fluorapatite synthesized with the sintering temperature of 900 °C demonstrates the highest crystallinity, according to the diffractogram results, there is an 83% presence of the apatite phase at an angle of 31.8126°, with a crystal size of 79 nm and a particle size of 0.5 µm. Fourier-transform infrared spectroscopy analysis on the sample showed the presence of OH, OH−F, and PO43− functional groups. The sample showed a spongy surface morphology with hexagonal-shaped flowers—a Ca/P molarity ratio 1.67

Sintering energy conservation in extrusion-based 3D printing of porcelain ceramics blended with copper and allied alloys: A sustainable approach

This study investigates the use of copper particles in porcelain ceramics for reduced sintering temperature effort as a part of a sustainable environment. Porcelain powder is mixed with 10 wt% copper powder, 25.3 wt% water, and 12.6 wt% ethanol, and the rheological characterization is made. The rheological characterization of the initial slurry and the phases that evolved during sintering at various temperatures were studied. With suitable rheology of slurry, prototype parts are manufactured by 3D printing. The length-to-diameter ratio of the nozzle, stand-off distance, and type of underlying substrates are also observed to influence the printability. The sintering is performed in the temperature range of 500 °C–1200 °C. The sintered parts were characterized for various phases in the selected temperature range. In addition, a study was conducted to find sintering temperature variation with the percentage of copper addition made by mixing brass and bronze with multiple compositions of zinc and tin, respectively. Once the standards are established with copper in a research-based printer, porcelain with other elements is printed on a bulk printer, ensuring repeatability. The retention of natural binder kaolinite at various temperatures is also verified. This study also opens a new dimension for sustainable multi-material ceramic 3D printing with increased solid loading at ease with required customization. The results showed that adding copper particles to the porcelain powder reduced the sintering temperature by up to 200 °C. The study concluded that adding copper particles to porcelain is a promising method for sustainable 3D printing of ceramics.

An atomistic investigation on the sintering behaviour of AlSi10Mg nanoparticles during the laser powder bed fusion process

The laser powder bed fusion process represents an innovative manufacturing technique within the context of Industry 4.0. This method involves creating components in a layered manner by melting or compacting together individual powder particles. The process of compacting multiple-component metal powders significantly affects the mechanical and physical characteristics of the final product. In this particular investigation, an atomistic model is constructed to gain a deeper understanding of how AlSi10Mg metal powders with multiple components fuse together. This model is employed to examine how the compacting behavior changes for AlSi10Mg particles that are 4 nm in size at varying sintering temperatures: specifically, 800 K, 950 K, and 1100 K. The growth of interparticle connections (referred to as “necks”) and the ratio of shrinkage are quantified over time as the compacting process takes place. The results of the simulations reveal that increasing the sintering temperature leads to a wider neck, expanding from 51.81 Ã… to 53.63 Ã…. Correspondingly, the shrinkage ratio also increases as the sintering temperature rises. These findings offer insights into enhancing the manufacturing conditions and material formulations for multi-component nano powders.

MECHANOSYNTHESIS OF MMC Cu-C DOPED WITH Ti FOR APPLICATION OF PANTOGRAPH CONTACT STRIP (PCS)

This research was conducted to determine the effect of the addition of Titanium (Ti) and the sintering temperature variation on MMC CuC alloys as reinforcing elements. The process of this research uses powder metallurgical method with an alloying technique in Mechanical Alloying using a Planetary Ball Mill (PBM) machine with a speed of 600 rpm for 2 hours, the ratio of powder to the ball mill is 10:1. The compacting process is carried out using dies 11 mm in diameter and compacting pressure of 90 Kg/cm2. The sintering process is carried out three times, with variations in sintering of 800oC, 900oC, and 1000oC with sintering time for 1 hour in the tube furnace in the argon gas vacuum environment. The number of samples used in this study amounted to 9 samples with variations in alloy and temperature sintering, consist of MMC CuC alloy with addition of Ti 0%, 0.5%, 1.5% (T=800 oC), MMC CuC with addition of Ti 0%, 0.5%, 1.5% (T=900 oC), and MMC CuC with addition of Ti 0%, 0.5%, 1.5% (T=1000 oC). The tests included Vickers hardness testing, metallography testing, XRD testing, and SEM-EDS testing. The addition of Ti elements and varying sintering temperature had an effect on the hardness value of MMC CuC material with the highest hardness value in samples with 1.5% Ti alloy (800oC) which is 87.25 HV, and the lowest porosity value is 2.491% in the sample of 1.5% Ti (1000oC).