Effect Of Sintering Conditions Research Articles

Effect of sintering conditions on the hardness of porous pure magnesium fabricated by MM-SPS process

Effect of sintering conditions on the hardness of porous pure magnesium fabricated by MM-SPS process

An alternative approach to obtaining low coercivity ZnMn ferrite ceramics with the use of solution combustion method: effect of sintering conditions on structural, morphological and magnetic parameters

An alternative approach to obtaining low coercivity ZnMn ferrite ceramics with the use of solution combustion method: effect of sintering conditions on structural, morphological and magnetic parameters

Effect of sintering conditions on colossal dielectric properties of (Tb1/2Nb1/2)0.01Ti0.99O2 ceramics

In this study, we investigated various sintering temperatures (1200 °C−1450 °C) and durations (2–6 h) conditions for preparing (Tb1/2Nb1/2)0.01Ti0.99O2 (TNTO) ceramics. By employing high sintering temperatures (≥1350 °C) and extended sintering durations (≥4 h), we successfully achieved ultra–high dielectric permittivity values (ε′ ∼ 2.2 − 4.1 × 104) and remarkably low loss tangent values (∼0.025−0.079). Remarkably, the temperature coefficient of the TNTO ceramic, sintered at 1350 °C, exhibited exceptional stability, maintaining a value of approximately 15% even at 200 °C. Additionally, we examined the phase structure and microstructure of the TNTO ceramics to gain insights into their colossal permittivity (CP) behavior. The analysis revealed the presence of rutile TiO2 and TbNbTiO6 phases, and the ceramics exhibited a high–density microstructure under high–temperature sintering conditions. The impedance spectroscopy analysis revealed that the primary contributor to the observed CP behavior was the interfacial polarization mechanism. The observed increase in the ε′ value, correlated with the enlargement of the average grain size, can be attributed to the effect of the internal barrier layer capacitor. However, when the sintering time ≥4 h, the grain size did not significantly affect the ε′ value, possibly due to reaching the maximum capacity of electron production for the interfacial polarization process (i.e., the maximum intensity of polarizability). This study provides valuable insights into optimizing the sintering conditions for TNTO ceramics and related compounds, laying the groundwork for the development of a new CP oxide suitable for practical applications.

Study on Effect of Sintering Conditions on Exploration of Barite Raw Materials

. The object of works has been the barite-bearing technogenic wastes. The wastes include the final tailings of the Karagailinsky mining and processing plant. They are stored in the tailing dumps, and they have been formed during the flotation concentration of the barite-polymetallic ores of the Karagaily deposit [1-2]. These tailing dumps occupy a huge territory. Thus, the dumps are pollution sources of soil, air and water by the heavy metals and barite dust. These wastes have been not recycled yet, i.e. there is no effective technology that would allow the cost-effective production of the quality commercial products. The issue with the barite-bearing waste recycling is its complex mineralogical composition. Thus, it leads to the inefficiency of the traditional recycling methods such as the acid leaching and flotation [3-5]. In order to solve these issues on this raw materialrecycling, some methods should be found to explore the ore mineral aggregateswith the silicon-bearing gangue minerals [6-7]. A promising solution to the issueis to explore the raw materials with the chemical methods, in particular, by a method of ammonium fluorosulfate desiliconization. Studies have been performed to explore the barite raw material by the sintering with ammonium fluorosulfate. As a result, a mathematical model of the exploration has been created and the optimal conditions for this process have been determined. The partial dependences of the raw material exploration on temperature, sintering time and consumption of the exploring reagents have been obtained. Based on the partial dependencies, a mathematical model of the sintering as a generalized multifactor equation has been created. This equation has determined the optimal conditions to explore the barite raw materials. A scheme of ammonium fluorine sulfate exploration of the barite raw materials has been developed

Effects of sintering condition on giant dielectric and nonlinear current-voltage properties of Na1/2Y1/2Cu3Ti3.975Ta0.025O12 ceramics

The effects of sintering conditions on the microstructure, giant dielectric response, and electrical properties of Na1/2Y1/2Cu3Ti3.975Ta0.025O12 (NYCTTaO) were studied. A single phase of Na1/2Y1/2Cu3Ti4O12 and a high density (>98.5%) were obtained in the sintered NYCTTaO ceramics. First–principles calculations were used to study the structure of the NYCTTaO. Insulating grain boundaries (i–GBs) and semiconducting grains (semi–Gs) were studied at different temperatures using impedance and admittance spectroscopies. The conduction activation energies of the semi–Gs and i–GBs were Eg ≈ 0.1 and Egb ≈ 0.6 eV, respectively. A large dielectric constant (ε′ ≈ 2.43–3.89 × 104) and low loss tangent (tanδ ≈ 0.046–0.021) were achieved. When the sintering temperature was increased from 1070 to 1090 °C, the mean grain size slightly increased, while ε′ showed the opposite tendency. Furthermore, the breakdown electric field (Eb) increases significantly. As the sintering time increased from 5 to 10 h, the mean grain size did not change, whereas ε′ and Eb increased. Variations in the dielectric response and non–linear electrical properties were primarily described by the intrinsic (Egb) and extrinsic (segregation of Na–, Cu–, Ta–, and O–rich phases) properties of the i–GBs based on the internal barrier layer capacitor effect.

Effect of Sintering Conditions on the Electrical Properties of Lead-Free Piezoelectric Potassium Sodium Niobate-Based Ceramics

Lead-free piezoelectric 0.92(K0.445Na0.5Li0.05)NbO3-0.08BaZrO3 (KNLN-BZ) ceramics were prepared via conventional sintering. Single-step, 2-step and 3-step temperature-controlled conditions were designed. The structure and electrical properties of ceramics obtained using different temperature-controlled procedures were systematically studied. It was found that ceramic prepared using the 3-step method with a holding time of 20 h showed the highest electrical properties. The Curie temperature was approximately 286 °C, and the dielectric constant and dielectric loss at room temperature were 1350 and 4.5% at the frequency of 1 kHz, respectively. The highest remanent polarization, piezoelectric strain and piezoelectric coefficient, d33*, were obtained 60 °C, indicating a phase transition between ferroelectric phases. Although the ceramics did not show excellent piezoelectric properties, the 3-step sintering method can be considered an effective method to optimize the electrical performances of KNN-based ceramics. Combined with an appropriate composition, ceramics with excellent electrical properties could be obtained. This study provides a path to enhance the density and electrical properties for KNN-based ceramics with simple composition and potential for industry application.

Effect of Sintering condition on Magnetization and Microstructure of CuxCo(1-x)Fe2O4 Ferrites

Effect of Sintering condition on Magnetization and Microstructure of CuxCo(1-x)Fe2O4 Ferrites

Filament extrusion-based additive manufacturing of 316L stainless steel: Effects of sintering conditions on the microstructure and mechanical properties

Filament extrusion-based additive manufacturing of metals offers an alternative to the widespread beam-based counterparts. The microstructure obtained from extrusion-based techniques differs greatly from the ones obtained by beam-based additive manufacturing, as a sintering process is used, in contrast to the rapid solidification of a melt pool. In this study, the microstructure of 316L stainless steel fabricated by filament extrusion is investigated as a function of debinding and sintering conditions. High-speed nanoindentation correlated with energy-dispersive X-ray mapping is employed for microstructural characterization. High sintering temperatures of 1350 °C, an atmosphere of pure H2, and a cooling rate of 60 K/m are found to result in the optimal microstructure. High densities are obtained due to accelerated densification, enabled by the introduction of diffusion paths due to δ-ferrite formation. At the same time, hard phases like oxides or σ-precipitates with detrimental effects on the mechanical properties can be avoided. It is shown that the porosity can be quantified by analysis of hardness and modulus data from nanoindentation mapping. The values obtained are in good agreement with optical and Archimedes immersion method measurements. Tensile tests of 3D-printed and sintered specimens show excellent ductility and strength in comparison to literature. We demonstrate that 3D printing of 316L filaments and sintering with the optimized conditions results in material properties comparable to bulk values.

Investigation of glass sintering to improve strength and interfacial interactions in glass‐to‐AISI 316L metal joints

AbstractThe relationship between sintering and glass‐to‐metal bonding, which are almost the initial and the last stages of glass‐to‐metal seal production, has been demonstrated in this study. In this context, a type of barium alkali silicate glass was prepared, and thermal properties were determined by differential thermal analysis, dilatometer, hot‐stage microscope, and high‐temperature viscosity analysis. Detailed porosity investigations were examined with an optical microscope and ImageJ quantitative analyses, after binder removal and sintering processes carried out at different temperatures and times. An increase in porosity was observed when the sintering and binder removal temperatures and times were increased. The bending strength of the sintered glass sample was decreased with the increment in porosity. A typical housing material AISI 316L stainless steel was used for preparing glass‐to‐metal joints. The high porosity after sintering caused larger bubbles to form after bonding and reduced the shear strength. The effect of sintering conditions on the interfacial interaction for glass‐to‐metal joints are revealed by cross‐sectional scanning electron microscopy–energy‐dispersive spectrometer analyses. Atomic force microscopy analyses and contact angle measurements were conducted to supplement investigation. This study addressed that the mechanical strength and chemistry of glass‐to‐metal joints showed strong dependency on glass sintering conditions.

The effect of sintering conditions on thermal stability and magnetic properties of Ni0.4Zn0.2Mn0.4Fe2O4 ferrites

The effect of sintering conditions on thermal stability and magnetic properties of Ni0.4Zn0.2Mn0.4Fe2O4 ferrites

Effects of Sintering Conditions on Giant Dielectric and Nonlinear Current-Voltage Properties of TiO2-Excessive Na1/2Y1/2Cu3Ti4.1O12 Ceramics.

The effects of the sintering conditions on the phase compositions, microstructure, electrical properties, and dielectric responses of TiO2-excessive Na1/2Y1/2Cu3Ti4.1O12 ceramics prepared by a solid-state reaction method were investigated. A pure phase of the Na1/2Y1/2Cu3Ti4.1O12 ceramic was achieved in all sintered ceramics. The mean grain size slightly increased with increasing sintering time (from 1 to 15 h after sintering at 1070 °C) and sintering temperature from 1070 to 1090 °C for 5 h. The primary elements were dispersed in the microstructure. Low dielectric loss tangents (tan δ~0.018–0.022) were obtained. Moreover, the dielectric constant increased from ε′~5396 to 25,565 upon changing the sintering conditions. The lowest tan δ of 0.009 at 1 kHz was obtained. The electrical responses of the semiconducting grain and insulating grain boundary were studied using impedance and admittance spectroscopies. The breakdown voltage and nonlinear coefficient decreased significantly as the sintering temperature and time increased. The presence of Cu+, Cu3+, and Ti3+ was examined using X-ray photoelectron spectroscopy, confirming the formation of semiconducting grains. The dielectric and electrical properties were described using Maxwell–Wagner relaxation, based on the internal barrier layer capacitor model.

Sintering characteristics of plate-like bismuth titanate ceramics with preferred c - axis orientation for memory storage devices

Bismuth titanate (Bi4Ti3O12) (BIT) has been an attractive material due to its high Curie temperature, large remnant polarization and relatively low processing temperature, making it suitable for piezoelectric, pyroelectric and non-volatile random access memory storage devices. In this present work, polycrystalline textured bismuth titanate ceramics were synthesised by the cost-effective molten salt synthesis method. The effect of sintering conditions on the structural, morphological and dielectric properties have been carried out in detail. The X-ray diffraction studies reveal the formation of the monophasic structure of BIT ceramics with a preferential orientation along the c-axis. It is also noticed that the orientation along the c-axis increases with an increase in sintering temperature. Interestingly, the parameters like crystallite size and micro-strain calculated from the Williamson - Hall method could be tailored as a function of sintering temperature. The microstructural studies carried out using FESEM technique suggested the presence of plate-like morphology of BIT ceramics and subsequently, the elemental mapping analysis used to confirm the uniform distribution of the elements Bi, Ti and O present in the ceramic sample. The Fourier transform infrared and X-ray photoelectron spectroscopic studies have been done to identify the constituent chemical bonds and oxidation states of BIT ceramics. Interestingly, it is noted that the value of the dielectric constant increases with the increase in sintering temperature of BIT ceramics. Furthermore, the high dielectric constant value of 200 obtained at 100 kHz for 950 °C sintered sample could establish this material for the embedded capacitor in memory storage devices.

Correlating the Microstructure with the Mechanical Behaviour of Titanium Structures Produced by Robotic Assisted Deposition

Titanium is a high-performance material with relatively high specific mechanical strength, high fracture toughness, low elastic modulus, and high corrosion resistance with important applications in aerospace, medical, and chemical industries. Nowadays, developing and fabrication of titanium-based structures by means of additive manufacturing technologies, especially robotic assisted deposition, is exceptionally attractive and challenging. The study was aimed to evaluate the effects of sintering conditions on microstructure and mechanical behaviour of complex robotic deposited porous titanium structures. The results demonstrated that the mechanical behaviour of such structures can be determined not only by their macrodesign, but also microstructural features, such microporosity and grain size controlled by sintering conditions, have an effect on it. The stiffest titanium structure with the densest filaments and with elastic modulus in a range of that of human trabecular bone was obtained by sintering at 1400 °C for 10 h.

Application of the Sinter-HIP Method to Manufacture Cr-Mo-W-V-Co High-Speed Steel via Powder Metallurgy.

1.2C–4Cr–4Mo–10W–3.5V–10Co–Fe high-speed steel (JIS SKH57; ISO HS10-4-3-10) is often manufactured via casting and forging. By applying powder metallurgy, the properties of the abovementioned material can be improved. In this study, the effects of sintering conditions on the formation of precipitates and pores are evaluated. Additionally, strength with and without hydrostatic pressure during sintering is evaluated via static bending and impact tests. Sintering via hot isostatic pressing (HIP) at 1463 K can effectively eliminate pores and prevent the coarsening of precipitates. Toughness and strength improved by 50% by applying HIP.

The effect of sintering conditions on the superconducting properties of melanin doped MgB2

In this work, the melanin-doped MgB2 samples were prepared under the same condition at different sintering temperatures. The XRD quantitative analysis indicates an increase in crystallite size with increasing sintering temperature. The pinning mechanism tends to be a collective of surface and point pinning in an indication of the role of the impurities and secondary phases in the forming of flux pinning centers. The electrical and magnetic measurements show significant enhancement on critical current density obtained from the doped samples compared to the pure ones. Enhancing critical current density and critical fields depend on the sintering conditions. Sintering at low-temperature results in a high critical current density and critical field values. The resistivity and the related superconducting parameters measurements were also completed.

Effect of sintering conditions on the radiation shielding characteristics of YBCO superconducting ceramics

The search for protective materials against harmful ionizing Radiation has been increasing dramatically in recent years. High-temperature superconductors could be a pioneer in this field. In this paper, high-temperature superconducting ceramics were fabricated by the solid-state process. The effect of synthesis factors such as sintering temperatures and preparation medium on the structure, morphology, and radiation shielding properties were studied. The X-ray diffraction results showed that YBCO ceramics had been successfully prepared. The scanning electron microscope results showed that the sintering temperatures affected the morphology aspect of the ceramics. The increase of the sintering temperature from 930 °C to 950 °C increased the mean grain size and the physical properties of the ceramics. The ceramics prepared under an oxygen flux atmosphere exhibited the highest grain size (8.53 μm) with the ultra-lowest porosity (1.10%) and improved electrical transport property. Accordingly, the synthesis factors greatly influenced the radiation shielding performance of the prepared ceramics. The analysis was performed using Monte Carlo simulation. The linear attenuation coefficient (μ) was simulated in the energy interval between 0.244 and 2.506 MeV. The results demonstrated that the μ values reduced exponentially from 1.149 to 0.228 cm−1 (for Y93), from 1.255 to 0.249 cm−1 (for Y95A), and from 1.332 to 0.263 cm−1 (for Y95O). Moreover, the fabricated ceramics' attenuation capacity affected the ceramics' sintering temperature. The Y93 sample with a sintering temperature of 930 °C has linear attenuation coefficient values between 1.149 and 0.228 cm−1, which is considered the lowest μ values in the current study. We investigated the relationship between the porosity and the linear attenuation coefficient of the fabricated ceramics, which indicates that the linear attenuation coefficient values decrease linearly with raising the porosity ratio.

Filament Extrusion-Based Additive Manufacturing of 316l Stainless Steel: Effects of Sintering Conditions on the Microstructure and Mechanical Properties

Filament Extrusion-Based Additive Manufacturing of 316l Stainless Steel: Effects of Sintering Conditions on the Microstructure and Mechanical Properties

Effect of sintering conditions on optical and mechanical properties of MgAl2O4/Al2O3 laminated transparent composite fabricated by spark-plasma-sintering (SPS) processing

To realize a high hardness in transparent MgAl2O4, the MgAl2O4/Al2O3 laminated composite was fabricated by a one-step spark-plasma-sintering (SPS) method. By sintering at a temperature of 1225 °C for 10 min and at a heating rate of ≤ 10 °C/min under a pressure of 300 MPa, the MgAl2O4/Al2O3 laminated composites can attain a high hardness with maintaining the wide band transparency. The in-line and IR transmission were ∼50 % at the visible wavelength of 500 nm and >77 % at the wavelength of 4 μm, respectively. The Vickers hardness measured on the surface of the Al2O3 layer perpendicular to the MgAl2O4/Al2O3 stacking exhibited 29 GPa, which is higher than those of the monolithic Al2O3 (26.6 GPa) and MgAl2O4 (17.2 GPa). The wide band transparency and mechanical properties can be realized by simultaneously attaining smaller grain sizes and higher densities of both the MgAl2O4 and Al2O3 phases in the laminated composite by optimizing the SPS conditions.

Effect of Sintering Condition on Tensile Strength of Fe-based Non-equiatomic High Entropy Alloy

Effect of Sintering Condition on Tensile Strength of Fe-based Non-equiatomic High Entropy Alloy

Dielectric, mechanical and thermal properties of ZrO2–TiO2 materials obtained by microwave sintering at low temperature

The sinterability of 3Y-TZP/TiO2 materials using micrometre-sized ZrO2 and nanometre-sized TiO2 (16 wt%) by one-step fast microwave sintering at low temperature (1200–1300 °C) was investigated. Firstly, in situ detailed analysis of the dielectric properties of the material with temperature was carried out in order to measure the capacity of the material to transform microwave energy into heat. Another related parameter associated to microwave sintering is the penetration depth of the microwave radiation into the material, which showed great homogeneity from 400 °C. Secondly, the effect of sintering conditions on microstructure, density, hardness and coefficient of thermal expansion was evaluated. The X-ray diffraction study and microstructural characterization demonstrate that it is possible to obtain fully dense pieces (>99%) by microwave sintering, a condition yielding to a coarse-grained (~1–2 μm), quite hard (~13.7 GPa) 3Y-TZP/TiO2 material. However, the most important feature is the significant reduction of the thermal expansion coefficient (8·10−6 K−1) as compared to that of 3Y-TZP. In addition, the results from conventional sintering at 1400–1500 °C with 2 and 6 h of dwell time are examined and compared. The materials obtained at 1500 °C showed high density with grain size and hardness similar to those obtained by microwave but with a dramatic difference in the power consumption of the sintering cycle, since the materials obtained by microwave used a maximum absorbed power of 120 W and a heating cycle of only 40 min.