Effect Of Sintering Method Research Articles

Effects of sintering additives and sintering methods on the mechanical, antimicrobial and optical properties of Si3N4 bioceramics

Si3N4 bioceramics were fabricated using GPS and SPS method with MgO-RE2O3 (RE = La, Nd, Gd, Ho and Lu) sintering additives. The effect of sintering methods and sintering additives on the grain growth, mechanical, antimicrobial properties and color of Si3N4 bioceramics were studied. Samples sintered with GPS are composed of β-Si3N4 and samples sintered with SPS are composed of α-Si3N4 and β-Si3N4. The growth of β-Si3N4 grains in samples sintered with GPS are more adequate. Samples sintered with GPS exhibit a S. aureus inactivation rate up to 98% and a bright color appearance with a hardness of about 13 GPa and a fracture toughness up to 7.5 MPa m1/2, suitable for dental implants. And samples sintered with SPS exhibit a hardness of about 17 GPa and a fracture toughness about 6 MPa m1/2.

Study on the Intrinsic Correlation between Sintering Method, Ion Diffusion, and Dielectric Properties of Ba0.5Sr0.5TiO3‐ZnAl2O4 Composite Ceramics

AbstractBa0.5Sr0.5TiO3‐ZnAl2O4 composite ceramics of different components are prepared by solid‐phase sintering and microwave sintering, respectively. The ion diffusion phenomenon between the two phases under different sintering methods and the effect of sintering method on the microstructure and dielectric properties of composite ceramics are studied. The results show that during solid‐phase sintering, the generation of liquid phase can effectively enhance the ion diffusion between the two phases. Compared with solid‐phase sintering, microwave sintering effectively reduces the sintering temperature of composite ceramics, and the refinement of grains enhances the ion diffusion between the two phases, resulting in an increase in the Ba/Sr ratio, and the Curie temperature moves to high temperature and increases the tunability. Under microwave sintering conditions, when the ZnAl2O4 content is 50 wt%, the tunability of the composite ceramics reaches 40.03%, and it has a good Q‐value.

Effect of sintering methods on properties of Cu-Based composite reinforced by mechanically alloyed Cu–Mo–C powder

Mechanically alloyed (MA-ed) Cu–Mo–C powder was synthesized to prepare MA-ed Cu–Mo–C/Cu composite. Phase transformation investigation of the MA-ed powder showed Mo2C was in-situ formed at 900 ​°C. The composite samples in the ratio of 1%Mo2C were sintered by Spark plasma sintering (SPS) and conventional sintering. In comparison to conventional sintering, the reinforced particles of SPS sample are better bonded with Cu matrix. SPS sample has higher tensile strength (452 ​MPa), higher density (8.84 ​g ​cm−1), higher conductivity (84IACS%) and higher hardness (160 ​MPa).

Effects of Sintering Method and BaTiO3 Dopant on the Microstructure and Electric Properties of Bi (Fe0.9Al0.05Yb0.05) O3-Based Ceramics

The (1 − x) Bi (Fe0.9Al0.05Yb0.05) O3–xBaTiO3 (BFAYO-x BTO) ceramics were synthesized by microwave sintering (MWS) and conventional sintering (CS) methods. The crystal structure, surface morphology, dielectric and ferroelectric properties were investigated. XRD patterns show that BTO tetragonal and BFO rhombohedral phases coexist in both MWS and CS samples, and that the diffraction peaks of MWS samples shift to lower angles due to the larger ionic radius of Ba2+ compared with Bi3+. The lattice constant of BFAYO-x BTO ceramics increases with the increase of BTO content. It was found that the average grain size of the MWS ceramic is much smaller than that of the CS ceramic. Dielectric measurements reveal that the dielectric loss and dielectric constant increase with BTO content increasing. The introduction of BTO into BFAYO-based ceramic contribute to the enhancement of the dielectric relaxation behavior. The P–E hysteresis loops demonstrate that the remnant polarization (Pr) and the coercive field (EC) of the MWS samples are smaller than those of the CS samples. Pr and EC first increase, then decrease and then increase again with the increase of BTO content. The maximum and minimum values of the remnant polarization were obtained at x = 0.25 and 0.3, respectively.

Microstructural and Electrochemical Properties of Alkaline Earth Metal-Doped Li Garnet-Type Solid Electrolytes Prepared by Solid-State Sintering and Spark Plasma Sintering Methods

Li-stuffed garnet-type solid Li-ion electrolytes have been considered as a promising candidate for all-solid-state Li batteries. In this work, alkaline earth metal-doped Li garnet-type solid Li-ion electrolytes, Li6.5La2.5A0.5TaZrO12 (A = Ca, Sr, Ba) were prepared by conventional solid-state sintering (CSS) and spark plasma sintering (SPS) methods. The effect of sintering methods on the structural and electrochemical properties of the solid electrolytes was investigated by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). Among the investigated compounds, Sr-doped garnet-type Li6.5La2.5Sr0.5TaZrO12 prepared by the SPS method showed the highest Li-ion conductivity of 3.08 × 10–4 S cm–1 at 20 °C and the lowest activation energy of 0.35 eV. Both Sr- and Ba-doped samples exhibited a critical current density of 0.15 mA cm–2, and the Sr-doped Li6.5La2.5Sr0.5TaZrO12 sample showed the lowest Li-ion charge-transfer resistance of 139 Ω cm2 at room...

Study on the growth kinetics of Al2O3 columnar crystal in Al2O3 matrix composite ceramics prepared by microwave sintering

In this paper, the grain growth kinetics of 10Nb2O5-7.5La2O3-82.5Al2O3 (volume fraction) composite ceramics prepared by microwave sintering were researched. The effect of microwave sintering processes on the grain growth kinetics of Al2O3 columnar crystal were investigated, and the effect of sintering methods on the grain growth kinetics of Al2O3 columnar crystal were analyzed by comparison with conventional sintering. The growth mechanisms of Al2O3 columnar crystal in the composite ceramic were proposed. The results show that there are three phases of Al2O3, LaNbO4 and Nb2O5 in the composite ceramic, the grain growth kinetics exponents of Al2O3 columnar crystal in the composite ceramics decrease with the increase of sintering temperature, and the growth activation energies increase with the increase of holding time; the grain growth kinetics exponents in the minor axis direction are larger than those in the major axis direction. The decisive factor for the growth rate of Al2O3 columnar crystal is the wettability of liquid phase LaNbO4 on grain boundaries under high temperature conditions. The grain growth kinetics exponents of the major axis and minor axis of Al2O3 columnar crystal during microwave sintering are lower than those of conventional sintering. Therefore, the microwave sintering technology is superior to conventional sintering technology in promoting the growth of Al2O3 columnar crystal in the composite ceramics.

The effect of inductive sintering to iron based powder metal parts

Sintering is carried out by heating the graphite mold during pressing rather than direct heating of samples by eddy currents in many sintering applications. The effect of the induction on the powder metal samples is not fully visible due to graphite mold. The aim of this study is to observe the direct effect of eddy currents to powder metal parts. For this purpose, sintering was performed in a copper coil after pressing without a mold. Pure iron powder and two different iron based powder mixtures were used. Copper was added to the iron powder for liquid phase formation, and carbon was added for the formation of alloy. Effect of sintering method, sintering duration, pre-sintering and sintering temperature were investigated. In addition, conventional sintering has also been applied for comparison. As the result of the studies it was observed that, direct heating of powder metal samples with induction generates completely different sintering kinetics. It provides better mechanical properties in shorter sintering durations only in some instances and electrical resistivity values play an important role about this. Also resistivity values can give a preliminary idea about the mechanical strength after sintering.

Effect of sintering methods and temperatures on porosity of the ceramics from aluminum oxinitride

The paper presents the results of studies of the effect of temperature regimes and time on porosity in ceramic samples made of aluminum oxynitride. Getting rid of the porous structure allows reducing the scattering of rays and, as a result, achieving the required optical characteristics.

Effect of Sintering Method on the Properties of Quartz Porous Ceramics

The sintering methods of quartz sand porous ceramics were researched with the low grade quartz sand along the Yangtze River via the vacuum sintering method in this paper, which lay technology foundation for researching new heat insulating materials. The quartz porous ceramics is obtained with the high performance cost, the quartz porous ceramics is sintered at 1050°C via the vacuum conditions, the density of ceramics is 1.267g/cm3, the porosity is 51.6%, the compressive strength is 3.184MPa, the porous ceramics show the homogeneous distribution micro-pore and good shape. The density and the compressive strength of prepared ceramics via the vacuum sintering both are higher than that of prepared ceramics via the atmosphere sintering, however, the porosity is shown the opposite results.

Effect of sintering methods and cobalt addition on the shape memory properties of porous TiNi-based alloy

The changes of shape memory characteristics and properties of the porous sintered TiNi-based alloy are possible by a choice of the sintering methods or use of cobalt doping additive, as the present investigation has showed. The comparative analysis of the temperature dependences of electric resistance and macrodeformation both alloys, obtained by reaction and diffusion sintering was conducted. Diffusion-sintered alloy have showed high shape memory parameters and a more uniform passing of martensitic transformations. This is connected with a larger fraction of TiNi phase (about 90 vol.%) after diffusion sintering. It was found that the martensitic transformation characteristics and reversibility of martensitic strain in the porous nickelid titanium depend on level of intrinsic stresses in the TiNi phase and stresses caused by Co impurity. The addition to 1.0 at.% Co decreases the internal stresses in the TiNi phase, and more than 1.0 at.% Co increases their due to the effect of precipitation hardening of the alloy.

Comparison of PMN–PT transparent ceramics processed by three different sintering methods

La-doped 0.75Pb(Mg1/3Nb2/3)O3–0.25PbTiO3 (PMN–PT) transparent ceramics were fabricated by uniaxial hot-pressing sintering, oxygen atmosphere sintering and two-stage sintering technology, respectively. PMN–PT ceramics fabricated by two-stage sintering method show the best densification and highest transparency. Its optical transmittance reaches to 70% at 900 nm which is very close to its theoretical transmittance 71%. The temperature dependent dielectric properties and P–E hysteresis loops of these three ceramics show that they all exhibit relaxor characteristics. Effects of sintering methods on the dielectric and ferroelectric properties, diffusivity coefficient, and polarization current density were investigated.

Effect of Sintering Method on the Microstructure and Dielectric Properties of Lead-Free BCZT Ceramics

Lead-free ceramic powders based on Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) were successfully fabricated by the conventional solid-state reaction method. Two kinds of sintering methods: zero-time sintering (ZTS) and conventional sintering (CS) were applied to obtain BCZT ceramics. The microstructure and dielectric properties of BCZT ceramics sintered from the ZTS and the CS method were systematically studied. It was found that the coarse-grained samples with grain sizes ~ 19-21 μm were obtained from the ZTS and the CS method. The CS method with a long time of dwelling was helpful for improving the dielectric properties of lead-free BCZT ceramics. The maximum dielectric constant of 9926 and low dielectric loss of 0.0108 were obtained at CS with 8h.

Preparation and characterization of single-phase NiMn2O4 NTC ceramics by two-step sintering method

In this paper, single-phase NiMn2O4 NTC ceramics were prepared by two-step sintering method. The effect of sintering method on the phase, microstructure and electrical properties of NiMn2O4 ceramics was systematically analyzed. The NiMn2O4 ceramics prepared by traditional single-step sintering method are multiphase while the ceramics prepared by two-step sintering method are single cubic spinel. Moreover, compared with the ceramics prepared by single-step sintering method, the ceramics prepared by two-step sintering method have smaller grains and more uniform microstructure. Ceramics prepared by two-step sintering method exhibit lower resistivity than that of ceramics prepared by single-step sintering method. Two-step sintering method is a feasible and effective way to prepare single phase ceramics and adjust the properties of NTC thermistors.

Vanadium carbide reinforced aluminum matrix composite prepared by conventional, microwave and spark plasma sintering

The effect of sintering method on the structure and mechanical properties of aluminum −10 wt% VC composite was investigated. Aluminum-VC metal matrix composite was prepared successfully by conventional (at 600 °C), microwave (at 600 °C) and spark plasma sintering (at 450 °C). The obtained results indicate that the aluminum −10 wt% VC composite prepared by SPS had the highest relative density (99 ± 0.6 ± %TD), bending strength (295 ± 15 MPa) and microhardness (232 ± 16 Vickers). The XRD investigations showed the decomposition of VC phase and the formation of Al3V intermetallic phase in the microwave-sintered samples. The SEM micrographs and EDS analyses revealed uniform distribution of reinforcement particles in SPS method and the formation of Al3V phase in microwave-sintered sample.

Effect of sintering method on the microstructure of pure Cr<sub>2</sub>AlC MAX phase ceramics

Effect of sintering method on the microstructure of pure Cr<sub>2</sub>AlC MAX phase ceramics

Effects of Sintering Method and Sintering Temperature on the Microstructure and Properties of Porous Y2SiO5

Porous Y2SiO5 ceramic is a promising high-temperature thermal insulator in harsh environment. However, all the published relevant works faced serious problems, such as severe linear shrinkage, low porosity and low strength. In this study, porous Y2SiO5 ceramic with low sintering shrinkage and high porosity was successfully prepared by foam-gelcasting method using gelatin as the gelling agent. The effects of sintering methods, including in situ reaction sintering and direct sintering, and sintering temperatures on the phase composition, microstructure, shrinkage, porosity, and compressive strength of porous Y2SiO5 were investigated. Compared with samples fabricated by direct sintering, porous Y2SiO5 ceramic prepared via in situ reaction sintering method has the merits of the low linear shrinkage of 1.0%–4.7%, low bulk density of 0.79–0.88 g/cm3, high porosity of 82.1%–80.1%, and high strength of 3.54–8.03 MPa, when the sintering temperatures increase from 1350 to 1550 °C. Porous Y2SiO5 has unique multiple pore structures, especially containing the interconnected small pores in skeleton. The thermal conductivity of porous Y2SiO5 is very low, which is 0.228 W/(m⋅K) for the sample with a porosity of 79.6%. This work reports an optimal processing method of highly porous Y2SiO5 with the potential application as high-temperature thermal insulation material.

A Review: Effect of Sintering Method on the Decomposition of Hydroxyapatite and Density of Hydroxyapatite Zirconia Composites

Hydroxyapatite (HA) is a biomaterial with excellent biocompatibility. However, the brittleness and low fracture toughness of HA have limited its biomedical applications. As such, HA has been incorporated with zirconia (ZrO2) to enhance its mechanical strength. However, ZrO2 addition decreases the phase stability of HA. HA decomposition is not favored because it decreases the mechanical strength of HA/ZrO2. In this paper, the effect of sintering on HA decomposition is reviewed. Experimental results show that hot isostatic pressing of HA/ZrO2 is one of the most effective methods to suppress HA decomposition, yielding the highest relative density compared with other sintering methods.

Sintering and Electrochemical Properties of Hydrogen Storage Alloys in the System Mg-Ni

We synthesized ceramic-type Mg2Ni alloys (hydrogen storage alloy) by sintering at high temperature in Ar atmosphere and applied the sintered materials to the anode of the metal hydride batteries. As a result, it was found that the samples were obtained as sintered alloys, mainly composed of hexagonal phase with a little MgO. The discharge capacity of the sintered sample was more than 150 mAhg-1on the 1st cycle. It decreased to lower than 50 mAhg-1after a few cycles, but the capacity was maintained over 20 cycles. The cycling capacity retention is due to the packed fusion of the alloy particles by sintering, which denotes a good effect of sintering method to prepare alloy materials.

Densification of TiCN Matrix Cermets by Microwave Sintering

TiCN matrix cermets were prepared by using traditional sintering and microwave sintering. The effect of sintering methods, sintering temperature and protective atmosphere to the densification process of as prepared material were discussed. The results show that microwave sintering can short the sintering time than the traditional sintering, but it need higher temperature to obtain approximate density. At 1500°C,holding 5min, vacuum microwave sintering can gain relative density of 99.5%. The relative density of TiCN matrix cermets under argon shield is lower than vacuum microwave sintering, and the microscopic particles is more small, but the uniformity of pore is reduced. Microwave sintering can greatly reduce energy consumption.

Surface Morphology and Conductivity Study of Inkjet Printed Traces from Ag Nanoparticle Inks

Non-contact printing of conductive traces for electronic device fabrication is attractive due to its low cost, high resolution and high throughput characteristics. Inkjet printing of Ag nanoparticle inks followed by thermal or photonic sintering has the greatest potential for commercialization. In this process, the chemical and physical properties of the ink formulation and post print processing have significant impacts on the performance of the printed traces. In this paper, the effects of sintering methods and process conditions on the surface morphology and conductivity of the fabricated Ag traces are discussed.