Effect Of Sintering Time Research Articles

Effect of sintering time on the characteristics of YBCO coated-conductor joints using nano-silver paste

Jointing YBa2Cu3O7-z (YBCO) superconducting coated-conductor (CC) tapes is becoming increasingly significant for magnet applications because of the limited length of single tapes. In this work, YBCO CC tapes stabilized by silver were connected by low-temperature sintering of nano-silver paste. The effect of sintering time and lapped length on the electrical properties of YBCO joints were systematically investigated. And the correlation between microstructure and bonding force of the joints with extending the sintering time was established. It is found that joints sintered within 1∼5 min exhibit relatively lower resistance, while the maximum axial tensile strength at room temperature (RT) was improved with increasing sintering time. Considering the electromechanical properties, ten min is selected as the optimal sintering time for nano-silver paste. The joint by this efficient technology possesses closely connected interface, similar critical current and axial tensile strength (RT) to the single CC tape. The joint resistivity is as low as ∼12.5 nΩ·cm2, which is much less than the traditional soldering joint.

Effect of Sintering Time and Cl Doping Concentrations on Structural, Optical, and Luminescence Properties of ZnO Nanoparticles

Zinc oxide (ZnO) nanoparticles were synthesized hydrothermally using zinc acetate dihydrate and sodium thiosulfate pentahydrate precursors. The synthesized powders were sintered in air at 600 °C for different durations with a Cl-doping concentration of 25 mg/g. The optimal sintering time was found to be 5 h, resulting in the successful formation of the ZnO phase with small particle sizes of around 90 nm, nominal atomic fractions of Zn and O (~50%, ~50%), and increased luminescence intensity. The ideal concentration of Cl was discovered to be 25 mg/g of ZnO, which resulted in the highest luminescence intensity. The ZnO luminescence characteristics were observed in emission bands peaking at approximately 503 nm attributed to the transition from oxygen vacancies. A considerable improvement in the emission intensity was observed with increased Cl doping concentration, up to eight orders of magnitude, compared to pristine ZnO nanoparticles. However, the luminescence intensity decreased in samples with higher concentrations of Cl doping due to concentration quenching. These preliminary outcomes suggest that Cl-doped ZnO nanoparticles could be used for radiation detector development for radon monitoring and other related applications.

Effect of sintering time on microstructure and optical properties of yttria-partially stabilized monolithic zirconia

ObjectivesTo evaluate the impact of speed sintering on the microstructure and optical properties of 3 and 5 mol% yttria-partially stabilized monolithic zirconias. Methods120 plate-shaped zirconia specimens (10x10x 0.4 mm) were prepared from three commercial 5 mol% yttria-partially stabilized zirconia blocks (5Y-PSZs); Katana UTML (Kuraray Noritake), Cercon xtML (Dentsply Sirona), and Zolid FX white (Amann Girrbach), and two commercial 3 mol% yttria-partially stabilized zirconia blocks (3Y-PSZs); Lava Plus (3 M ESPE) and InCoris (Sirona, GmbH). Specimens were either conventional sintered (CS) using a 7-hour program or speed sintered (SS) using a quick 90-minute program. The microstructure was inspected with a scanning electron microscope (SEM), and phase fractions were detected using x-ray diffraction analysis (XRD). Translucency (TP00), and contrast ratio (CR) were obtained using a spectrophotometer (VITA Easyshade V). Color difference (ΔE00) between both sintering processes was calculated with the CIEDE2000 formula. ΔE00 up to 1.8 was set as the acceptability threshold. Data were analyzed using two-way ANOVA, Krusakll-Wallis, and Mann-Whitney U tests. (n = 12, α = .05). ResultsGrain size was significantly decreased after SS for all tested materials (P < .0001). The average grain sizes of 5Y-PSZs were significantly larger than those of 3Y-PSZs. The atomic structure, microstructure, and transparency of CS and SS were all affected by the amount of yttria, the size of the crystals, and tetragonality. SS significantly reduced TP00 (F = 7135.95, P < 0.0001) and increased CR (F = 453.21, P < 0.0001). The CS Katana presented the highest TP00 and lowest CR value. ΔE00 between the CS and SS groups were clinically acceptable except for Lava, which had values above the set threshold (1.89). SignificanceSS altered the grain size and internal structure of the tested materials, which was reflected in translucency.

Effect of sintering time on electrical, ferroelectric, and piezoelectric performances of microwave synthesized sodium bismuth titanate ceramics

Herein, we report the synthesis of sodium bismuth titanate (Na0.5Bi0.5TiO3/NBT), a lead-free ceramic prepared via a cost and time-effective microwave synthesis route. This work presents the investigation of microstructural, electrical, and optical characteristics of NBT ceramics. The formation of a single-phase NBT sample sintered for 30 and 40 min (denoted as NBT 30 and NBT 40) is confirmed by Rietveld refinement and Raman measurement. FTIR spectroscopy is used to characterize the single-phase nature and to confirm the presence of desired vibrational spectra in the perovskite structure. Tightly packed micron-sized grains are observed from the field emission scanning electron microscopy. Due to the A-site disorder present in the lattice, two diffuse types of dielectric anomalies are present in the temperature-dependent dielectric plot for both samples. The maximum dielectric constant values of 1475 and 1628 are found for NBT 30 and NBT 40 samples at the transition temperature. From temperature-dependent AC conductivity measurement, NBT 40 samples show a higher value of conductivity in comparison to NBT 30. The PE hysteresis loops confirm the ferroelectric character present in both samples. An improved piezoelectric coefficient is observed with increasing sintering time and is found to be 80 pCN−1 for NBT 40. The optical bandgap of materials is 3.03 and 3.1 eV for NBT 30 and NBT 40, respectively.

Processing and Mechanical Properties of (Hf-Ta-Zr-Nb-Ti)C

The influence of the processing route on the microstructure characteristics and mechanical properties of high-entropy carbides was investigated. The experimental materials were prepared by a combination of ball milling and spark plasma sintering at the temperature of 2100 °C. The effect of sintering time (5 min, 10 min, and 20 min) on the microstructure development and properties of the investigated systems has been studied. The microstructure analysis was performed using scanning electron microscopy + EDAX analysis on the polished surfaces. Nanoindentation was used for the nano-hardness and Young’s modulus measurements. Micro-hardness was measured using Vickers method and indentation method using a Vickers indenter was used to determine the indentation fracture resistance – fracture toughness. The measured grain size values were in the range from 5 µm to 14 µm. The nano-hardness values changed from 36 GPa to 39 GPa and the indentation modulus of elasticity from 558 GPa to 577 GPa, respectively. The measured micro-hardness values were in the range from 18.93 GPa to 21.95 GPa and the indentation fracture resistance changed from 2.70 MPa.m1/2 to 3.50 MPa.m1/2, respectively.

The effect of sintering time on the tribological properties of automotive brake pads

In this study, the effect of sintering temperature on the physical, chemical and tribological effects of sintered automotive friction materials was investigated. Using the powder metallurgy method, 3 different samples were produced with the codes A1, A6 and A11. Mixing, pressing and sintering processes were applied respectively as production steps. Mixing time is 90 minutes, speed is 15 rpm. The pressing pressure is 250 MPa and the duration is 1 min. The sintering temperature was 800 °C and the sintering time was 1, 6 and 11 hours, respectively. The sintering process was carried out in the sintering mold using Argon gas. As the sintering time increased, it was observed that there was an increase in the time-dependent friction coefficients of the samples. Increasing the sintering time also increased the density of the samples. As the sintering time increased, the gap in the sample decreased, as it provided better bonding of the dustsers.

Effect of Sintering Time on the Mechanical and Corrosion Behavior of Zn–Mg Composites with a Core–Shell Structure Prepared by SPS

Effect of Sintering Time on the Mechanical and Corrosion Behavior of Zn–Mg Composites with a Core–Shell Structure Prepared by SPS

Fabrication of porous pure magnesium by MgH&lt;sub&gt;2&lt;/sub&gt; produced by mechanical milling and spark plasma sintering (MM-SPS) process

Pure magnesium (Mg) powders with stearic acid added as process control agent (PCA) were mechanically milled (MMed) using a vibration ball mill. The MMed powders were consolidated into bulk materials by the spark plasma sintering (SPS). Changes in hardness, thickness and solid-state reactions of the SPS materials have been examined by hardness measurements, vernier caliper and an X-ray diffraction (XRD), respectively. The Vickers hardness of the SPS material decreased with increasing sintering temperature. Minimum value of Vickers hardness was 17 HV. The thickness of the SPS material increased with increasing sintering temperature. However, little effect of sintering time on the thickness was observed. In the SPS materials, the formation of MgH2 by solid phase reaction was observed during sintering. During sintering, MgH2 was decomposed to produce hydrogen gas; and it contributed to expand the SPS materials. Porous pure magnesium could be formed using only the MM-SPS process without the addition of a foaming aid.

Effect of sintering time on phase, physical properties, microstructure and thermal conductivity of Y(Ba1-x La x )2Cu3O7-δ ceramics

This work investigates the effects of various sintering conditions on phase, physical properties microstructure and thermal conductivity of Y(Ba1-x La x )2Cu3O7-δ where x = 0, 0.05, 0.10, 0.15, 0.20 and 0.25 mol fraction. The sintering conditions involved the sintering temperature of 920 °C and sintering time of 6, 8, 10 and 12 h. It was found that pure phase could be obtained in the samples sintered for 6 h regardless of composition. However, small amount of BaCuO2 secondary phase was obtained at other sintering time. The relatively low density and significantly reduced grain size was obtained in the samples with high La content (e.g. x = 0.20 and 0.25) regardless of the sintering time. This showed that La addition had apparent effects on sintering ability and grain growth. Phase analysis indicated that the structure changed from orthorhombic to tetragonal when the La concentration reached 0.20 and 0.25 mol fraction. SEM images of all ceramics also indicated irregular shaped grains. The effects of variation in density, microstructure and composition on the thermal conductivity of all ceramics were also discussed in details.

The Investigation on Dimensional Stability in Some Sintered Powder Metallurgy Alloys

The subject of this research was to study the effect of sintering time on the dimensional characteristics of some powder metallurgy (PM) materials. The powders used in this study are prealloyed iron-based powders with Cu, Ni and Mo. The powders were single pressed at 600 MPa and the disc specimens have the dimensions of 8-6 mm. The green compacts were sintering in a laboratory furnace at 1150 ºC for 60, 75 and 90 minutes and air-cooled to room temperature. The density of green and sintered specimens, the porosity and the dimensional changes were evaluated.

The Effect of Sintering Time on The Formation of The BPSCCO-2212 Superconductor Phase at The Levels of Ca = 1.10 Using The Wet Mixing Method

This research was conducted to determine the effect of sintering time on to phase formation of superconducting BPSCCO-2212 with Ca content 1.10 by calculating the level of purity of the phases formed and looking at the microstructure. The variation of sintering time was 10, 20, 30, and 40 hours using the wet mixing method. The sample was calcinated at 800 °C for 10 hours and sintered at 830 °C. The XRD's characterization result showed that the highest volume fraction obtained in BPSCCO-2212/40 hours was 86.72%, while the lowest volume fraction of BPSCCO-2212/30 hours was 53.07%. The relatively high orientation degree of BPSCCO-2212/30 hours was 13.59%, while the lowest orientation degree of BPSCCO-2212/20 hours was 7.67%. The SEM's characterization result shows that all samples have not been oriented, and many voids (space between the plates) are still generated.

Effect of sintering time on the marginal and internal fit of monolithic zirconia crowns containing 3–4 mol% Y2O3

BackgroundShort-term sintering may offer advantages including saving time and energy but there is limited evidence on the effect that altering sintering time has on the accuracy of monolithic zirconia crowns. The purpose of this in vitro study was to investigate the effect of shortened sintering time on the marginal and internal fit of 3Y-TZP and 4Y-TZP monolithic crowns.MethodsSixty monolithic zirconia crowns were fabricated for the maxillary first molar tooth on the prefabricated implant abutment. Groups were created according to the material composition: 3Y-TZP Generation 1, 3Y-TZP Generation 2 and 4Y-TZP. Two different sintering protocols were performed: same final sintering temperature (1500 °C) and various rates of heating (10 °C/min and 40 °C/min), cooling down speed (− 10 °C/min and − 40 °C/min), holding time (45 and 120 minutes), and total sintering time (approximately 2 and 7 hours, respectively). The marginal and internal fit of the crowns were determined using the silicone replica technique. Comparisons between groups were analyzed using two-way ANOVA. Pairwise multiple comparisons were performed using t-test (p < 0.05).ResultsThe mean marginal gap values of 4Y-TZP zirconia revealed statistically significant increase for the short-term sintering protocol (p < 0.0001), while no difference was observed between the sintering protocols for the mean marginal gap values of 3Y-TZP groups. Although all groups showed clinically acceptable gap values, altering the sintering time had an effect on marginal fit of the crowns manufactured from 4Y-TZP zirconia.ConclusionsShortening the sintering time may lead to differences within clinically acceptable limits. The manufacturer’s recommendations according to material composition should be implemented with care.

Effect of sintering time on the microstructure and stability of Al2O3–ZrO2 composite powders under microwave-assisted sintering

The function of ceramic coating is closely related to the construction technology and the quality of ceramic powders. Generally, Al2O3–ZrO2 powders are rapidly sprayed on the material surface at high temperatures to obtain better performance. Improving the quality of Al2O3–ZrO2 powders can make them more widely used in ceramic coating. In this paper, microwave sintering was used to enhance the sintering process of the powders, and the effect of sintering time on the microstructure, properties, and stability of Al2O3–ZrO2 powders was investigated. The results proved that microwave heating could improve the crystallinity and stability of the samples. At 900 °C, the tetragonal phase content in samples with different sintering times were 63.05%, 63.25%, 62.39%, and 63.22%, respectively. The average particle sizes obtained by Gaussian fitting are 1.04 μm, 0.83 μm, 0.88 μm, 0.86 μm, respectively. The Gaussian fitting particle size data was consistent with the normal distribution. Compared with the particle size of raw material (1.10 μm), the particles were refined, and the dispersion effect was noticeable. Therefore, the best sintering time for microwave sintering Al2O3 stabilized zirconia was 2 h. This paper aims to provide reasonable data support for improving the preparation of high-quality Al2O3-PSZ ceramic powders and to guide the industrial production of Al2O3-PSZ powders.

Influence of sintering time on diffusion bonding of WC-10Co and AISI4340 by spark plasma sintering

It is challenging to obtain successful bonding between cemented tungsten carbide and steel due to the large differences in their physical and mechanical properties. We used spark plasma sintering (SPS) technique and successfully bonded WC-10Co and AISI4340 high-strength steel at a low temperature. The effects of sintering time (5–20 min with a gap of 5 min) on their diffusion bonding were examined. The microstructure of the bonded composite materials was evaluated, and formed phases were identified. The mechanical properties were investigated, and the importance of processing parameters of SPS was discussed. The results show a crack-free continuous metallurgical bonding achieved at 1000°C, and the bonding strength increased with increasing holding times of 5, 10, 15, and 20 min. The sintered WC-10Co powders obtained nearly full density (99.07%) with an average maximum hardness of 1763 HV5. A special arrangement was used to determine the tensile bonding-strength with maximum average of 152 MPa at 20 min.

The effect of microwave energy on sintering of an austenitic stainless steel reinforced with boron carbide

Microwave heating has emerged as an alternative to traditional sintering methods because it consumes less energy and requires shorter processing times. The use of microwave energy in the processing of austenitic stainless steel AISI 316L reinforced with dispersed boron carbide particles was investigated in this study. Different processing parameters were used to investigate the effect of sintering time and temperature, as well as the weight percentage of the ceramic added to the steel matrix, on the final material properties. The compressibility curve, elastic relaxation, and geometric density of green compacts were used to investigate their physical properties. The Archimedes method was used to determine density, and the statistical treatment of analysis of variance was used to determine porosity. Images obtained using optical microscopy and scanning electron microscopy revealed the formation of a second phase in different volumes. The results showed that 1100 °C and a 15-minute plateau were sufficient to sinter the material. AISI 316L samples containing 3 wt.% boron carbide demonstrated greater volumetric formation of secondary phases, resulting in a significant increase in the hardness of the austenitic composite developed.

The Effect of Sintering Time on Electronic Conductivity of LiFeGdPO4/C as a Lithium-Ion Battery Cathode

Lithium iron phosphate (LiFePO4) is an alternative cathode material choice in lithium-ion batteries because of its non-toxic nature, high voltage (3.45 V), the high theoretical capacity of LiFePO4 (170 mAh/g), low cost, non-reactive and has good structural properties stability. However, LiFePO4 has a low electronic conductivity (10-9-10-10 S/cm) and a low diffusion coefficient of Li+ ions (10-12-10-14 cm2/s), so it affects electrochemical performance. There are several ways to increase the conductivity. These are namely carbon coating, metal ion doping and optimizing the sintering time. Optimal sintering time will increase crystallinity, thereby increasing the value of electronic conductivity. Then using the right sintering time will get a lot of the desired phase content. This study aims to determine the effect of the sintering time variation 6 hours, 8 hours, 10 hours, 20 hours and 30 hours to increase the electronic conductivity of LiFeGdPO4/C. The synthesis method used is the carbothermal reduction method with the precursors used are LiH2PO4, Fe2O3, Gd2O3 and carbon graphite. LCR meter and XRD are used to characterize samples. The results obtained indicate that the effect of sintering time can increase the value of the electronic conductivity of LiFeGdPO4/C, with the highest conductivity value at a sintering time of 30 hours of 1.5296 x 10-7 S/cm.

Effect of reinforcement and sintering on dry sliding wear and hardness of titanium – (AlSi)0.5CoFeNi based composite

Owing to its weight-to-strength ratio, titanium is a widely used material, especially in gas turbine engines. It possesses a high melting point and corrosion resistance, however, exhibits poor wear resistance. An improvement in its tribological properties can be accomplished by the addition of a suitable reinforcement in metal matrix composite (MMC). In this research, titanium MMCs were fabricated through mechanical alloying (MA) followed by vacuum arc melting of 95% titanium reinforced with 5% of (AlSi)0.5CoFeNi high entropy alloy (HEA). Compaction was later done at 1000 MPa, while specimens were heat-treated at sintering temperatures of 900 °C and 1000 °C, with varying sintering times of 1 h and 2 h at 10–4 millibar vacuum. Microhardness and sliding wear rate of reinforced HEA specimens exuded improvement when compared to the Ti 900 °C 2 h specimen. Owing to the reinforcement, a reduction in wear rate and more than 5% improvement in microhardness had been observed, at higher sintering temperatures. The improvement was attributed to the synergistic effect of sintering time and temperature during the density and wettability analysis which was supported by the morphological analysis.

Effect of sintering time on the structural and magnetocaloric properties of Mn-Fe-P-Si-Ge-B alloys prepared by spark plasma sintering

Spark plasma sintering (SPS) has some advantages for preparing multifunctional materials, such as fast heating rate, short sintering time, and high compactness of products. In this work, we reported the effect of sintering time on the structural and magnetocaloric properties of Mn1.15Fe0.85P0.65Si0.13Ge0.2B0.02 prepared by SPS. The crystalline structure, microstructure and composition were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS). The results indicated that all the alloys crystallized in the hexagonal structure with a space group of P6 − 2m. A secondary phase of (Mn,Fe)3(Si,Ge) was not found in SEM but in TEM measurement. Transition temperature and isothermal entropy change were determined from thermal magnetization data measured in different constant magnetic fields. The results showed that the alloys undergo first-order phase transitions at transition temperatures between 248.8 K and 281.9 K. The maximum isothermal entropy change was found in the alloy sintered for 15 min, being 15.6 J ⋅ kg−1 ⋅ K−1 for a magnetic field change of 3 T. It indicated that no less than 15 min sintering time was required to prepare the alloy with good homogeneousness and large magnetocaloric effect. Consequently, SPS is an effective method for synthesizing the Fe2P-type alloys and the resultant alloys are promising magnetocaloric materials for magnetic refrigeration near room temperature.

Improved oxidation resistance properties of Si 3 N 4 /O′–SiAlON composite ceramics by a repeated sintering method

Si3N4/O′–SiAlON composite ceramics with superior oxidation resistance properties were fabricated by a repeated sintering method. The effects of sintering time on the phase evolution, microstructure, and oxidation resistance properties of the Si3N4/O′–SiAlON composite ceramics were investigated. The results indicated that the content of the O′–SiAlON phase and the densification of Si3N4/O′–SiAlON composite ceramics increased after two-time sintering. Furthermore, the thickness of the oxide layer of the Si3N4/O′–SiAlON composite ceramics after oxidation at 1100–1500°C for 30 h was not significant. Compared to the oxidation weight gain after the one-time sintering process, the oxidation weight gain of Si3N4/O′–SiAlON composite ceramics was 0.432 mg/cm2 after two-time sintering when oxidized at 1500 C for 30 h, which was reduced by 43.3%. The mechanism of the improved oxidation resistance properties was ascribed to the formation of more O′–SiAlON and the enhancement of the densification.

Preparing Copper Nanoparticles and Flexible Copper Conductive Sheets.

Nanotechnology is used in a wide range of fields, including medicine, cosmetics, and new material development, and is one of the most popular technologies in the field of flexible electronic products. For the present work, the chemical reduction method with environmentally friendly reducing agents was used to synthesize copper nanoparticles (CuNPs) with good dispersibility. The CuNPs were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and ultraviolet–visible spectrophotometry (UV–vis). After the CuNPs were formed, the solvent, polymers, and additives were added to form copper ink. Finally, the prepared copper inks were applied to flexible polyethylene terephthalate (PET) substrate under low sintering temperature and the effects of sintering time and different concentrations of sintering agent on resistivity were investigated. The results show that the copper nanoparticles synthesized by secondary reduction were smaller, more uniform, and better dispersed than those formed by primary reduction. Ethylene glycol has reducing effects under high temperatures; therefore, the CuNPs formed using the mixed solvent were small and well dispersed. The copper ink was applied on the PET substrate, treated with a formic acid aqueous solution, and sintered at 130 °C for 60 min, and its resistivity was about 1.67 × 10−3 Ω cm. The proposed synthesizing method is expected to have potential applications in the flexible electronic products field.