Effects of sintering temperature on the properties of alumina/hydroxyapatite composites

Effects of sintering temperatures on phase formation, microstructure and the dielectric properties of near MPB (1-x)BNT-xBT ceramics (x = 0.06 and 0.08) were investigated. The (1-x)BNT-xBT ceramics were prepared using a combustion technique. The phase purity, crystal structure and microstructure of the samples were examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Pure perovskite, which consists of rhombohedral and tetragonal phases, was found in the samples sintered below 1200°C. The average grain size tended to increase with increased sintering temperature. The density and the dielectric constant at room temperature increased with increasing sintered temperature up to 1200°C, thereafter they decreased. The ceramic composition with x = 0.08 exhibited the highest density (∼ 5.80 g/cm3) and dielectric constant (∼ 2829).

With the rapid development of society, the demand for information storage is increasing. Hence, research involving magnetic storage materials is gaining importance. In this study, Fe3Mn3Co60.66Si33.34 powders were prepared via mechanical alloying and sintering. The effect of the sintering temperature on the crystal structure was analyzed by X-ray diffraction, and the results showed that doped Co2Si powder was successfully prepared. Vibrating sample magnetometry was used to investigate the magnetic properties of Fe3Mn3Co60.66Si33.34, and showed that the coercivity of the samples decreased with increasing sintering temperature. Fe3Mn3Co60.66Si33.34 sintered at 950 °C yielded a magnetic saturation strength of 36.42 emu/g, coercivity of 135.92 Oe, and remanent magnetization of 4.97 emu/g. Electron microscopy analyses showed that the prepared particles were spherical, and the average grain size increased with increasing sintering temperature. The electromagnetic loss was analyzed by simulating electromagnetic parameters, which revealed that the electromagnetic loss tangent decreased with increasing sintering temperature. Hence, it is inferred that Fe3Mn3Co60.66Si33.34 powder materials sintered at high temperatures are expected to have suitable properties for magnetic storage applications.

This paper aims to investigate effect of spark plasma sintering temperature on mechanical property of Ti + ZrO2. The samples were prepared by SPS system with the different sintering temperature containing 900, 1,000, and 1,100 oC under the pressing pressure of 30 MPa in vacuum. The results show that hardness of Ti + 2 wt.% ZrO2 alloy increases with increasing sintering temperature. The highest hardness was 363 HV while suitable temperature for sintering Ti + 2 wt.% ZrO2 alloy was 1,100 oC. Further, the microstructure and crystal structure of all samples were single-α-phase structure with different in elements dispersion, which was related to amount of lattice expansion in the HCP structure.

Polycrystalline Bi 0.85Eu 0.15FeO 3 ceramics were synthesized by solid-state reaction method with rapid liquid phase sintering process at various sintering temperatures. The dependence of structural, microstructural, electrical, and magnetic properties on sintering temperature was systematically investigated. X-ray diffraction measurements reveal that single perovskite phase is developed in Bi 0.85Eu 0.15FeO 3 ceramics sintered at 850 and 870∘ C, while secondary phases can be detected in the samples sintered at 890∘ C due to the volatilization of Bi 3+ ions, and the crystallinity increases with increasing sintering temperature from 850 to 890 °C. The scanning electron microscopy investigation has suggested that the grain size increases with increasing sintering temperature from 855 to 890∘ C; while the pore size decreases with increasing sintering temperature from 850 to 870∘ C and then increases with a further increase of sintering temperature. The electrical and magnetic measurements show that the leakage current, dielectric constant, dielectric loss, and magnetic properties are strongly dependent on the sintering temperature. The Bi 0.85Eu 0.15FeO 3 ceramics sintered at 870∘ C have the lower leakage current, higher dielectric constant, and lower dielectric loss. The room temperature magnetization increases with increasing sintering temperature from 850 to 890 °C. The possible reason for all the above observations was discussed.

0.98{0.996[(0.95(K0.5Na0.5)NbO3–0.05LiSbO3]–0.004BiFeO3}–0.02ZnO (KNN–LS–BF–ZnO) ceramics were prepared by conventional sintering method. The effects of sintering temperature on the structure and properties of KNN–LS–BF–ZnO ceramics were studied. The results reveal that the sintering temperature has significant influence on the crystallizability and properties of KNN–LS–BF–ZnO ceramics. With the increase of sintering temperature from 1000 to 1060 °C, the main phase structure of KNN–LS–BF–ZnO ceramics changes from tetragonal phase to orthorhombic phase, and the grains become smaller and more homogeneous. When the sintering temperature is below 1020 °C, the maximum values of d33 = 278 pC/N, kp = 45 %, er = 1236 can be obtained, meanwhile the Pr and the Ec are higher than 22.5 μC/cm2 and lower than 1.2 kV/mm, respectively. However, the minimum value of tanδ = 2.62 % will be obtained when the sintering temperature is 1040 °C and the Qm value increases with the increase of sintering temperature from 1000 to 1060 °C. On the whole, the KNN–LS–BF–ZnO ceramics sintered at 1010 °C could obtained its best dielectric and piezoelectric properties.

The effect of sintering temperature on crystal structure and grain size of manganese seed originating from West Sumatera has been investigated using X-ray Diffractometer (XRD). This investigation is important in relation to the emergence of new phases of economic value at a certain temperature. The sintering temperature variations used are 600°C, 700°C, 800°C, 900°C, and 1000°C, respectively. The result of manganese ore investigation is known that sintering temperature variation, there is no change of structure from phases found in manganese ore which are equally tetragonal but there is change of grain size from the existing phases. For bixbyite and rhodonite phases, the grain size decreases with increasing sintering temperature. As for rhodonite and hausmannite phases, the grain size tends to increase with increasing sintering temperature.

Porous barium-strontium titanate ceramics were fabricated by adding corn- or potato-starch (are referred to as starch). The effect of sintering temperature on the microstructure and electrical properties of the porous ceramics was investigated. The room-temperature electrical resistivity of the barium-strontium titanate ceramics decreased with sintering temperature. The porosity and pore size were decreased and the grain size was increased with increasing the sintering temperature. The porosity and grain size of the barium-strontium titanate ceramics with corn-starch sintered at 1300 and 1450°C were 28.5, 22.6% and 3.2, 6.2 ㎛, respectively. The average pore sizes of the barium-strontium titanate ceramics with corn-starch sintered at 1300, 1400 and 1450°C were 0.5, 0.3 and 0.2 ㎛, respectively. The decrease in the room-temperature resistivity with increasing sintering temperature is attributed mainly due to the increase of grain size and the decrease of the electrical barrier height of grain boundaries as well as the partial decrease of porosity.

TiB2-BN composite ceramics combine excellent electrical conductivity, thermal shock resistance, high-temperature resistance, corrosion resistance, and easy processing of TiB2 and BN. However, in practical applications, their high-temperature oxidation resistance is poor and the resistivity distribution is uneven and changes substantially with temperature. A TiB2-BN-SiC composite ceramic with stable and controllable resistivity was prepared by introducing SiC into the TiB2-BN composite ceramics. In this work, spark plasma sintering (SPS) technology was used to prepare TiB2-BN-SiC composite ceramics with various TiB2-SiC ratios and sintering temperatures. The samples were tested by XRD, SEM, and thermal and mechanical analysis. The results show that as the volume ratio of TiB2-SiC was increased from 3:1 to 12:1, the resistivity of the sample decreased from 8053.3 to 4923.3 μΩ·cm, the thermal conductivity increased from 24.89 to 34.15 W/(m k), and the thermal expansion rate increased from 7.49 (10−6/K) to 10.81 (10−6/K). As the sintering temperature was increased from 1650 to 1950 °C, the density of the sample increased, the mechanical properties were slightly improved, and the resistivity, thermal expansion rate, and thermal conductivity changed substantially. The volume ratio and sintering temperature are the key factors that control the resistivity and thermal characteristics of TiB2-SiC-BN composite ceramics, and the in situ from liquid phases of FeB and FeO also promotes the sintering of the TiB2-BN-SiC ceramics.

The present study investigates the effect of compaction pressure and sintering temperature on densification response and mechanical properties of the Al–3.8Cu–1Mg–0.8Si–0.3Sn (2712) alloy. The compacts were pressed at 200 and 400 MPa and sintered at temperatures ranging from 570–630°C in vacuum (10−6 Torr). The objective of the present work is to obtain an optimum sintering conditions for achieving higher sintered densities and mechanical properties. The effect of sintering temperature is evaluated by measuring the sintered density, densification parameter, microstructure, phase changes and mechanical properties. While a higher sintering temperature results in densification enhancement, it also leads to microstructural coarsening. Significant improvement in mechanical properties is obtained through age-hardening of sintered alloy under various ageing conditions (T4, T6 and T8).

This paper describes thermoelectric properties of La-doped SrTiO 3 prepared by using a combination of combustion synthesis (CS) with post spark plasma sintering (SPS), on which effects of sintering temperature were mainly examined. In experimental, combustion-synthesized (CSed) samples (Sr 1-x La x TiO 3 , x = 0.08) were spark-plasma-sintered (SPSed) at temperatures from 1513 to 1663 K and the thermoelectric properties of sintered Sr 0.92 La 0.08 TiO 3 were measured from room temperature to 1073 K. In experimental sintering temperature range, sintering temperature didn't heavily affect the average grain size of sintered SLTO in the case that sintering temperature ranges from 1543 to 1603 K. However, when sintering temperature rose over 1603 K, the average grain size of sintered SLTO was dramatically affected and it increased with sintering temperature. With increasing sintering temperature, the effects of phonon scattering at grain boundaries decreased therefore, thermal conductivity of all sintered samples increased with sintering temperature. With increasing sintering temperature, electric conductivity of sintered SLTO increased and absolute value of Seebeck coefficient of sintered SLTO decreased because sintering at higher temperature caused the more oxygen defects which generate the larger carrier density. In conclusion, the product sintered at 1573 K showed the maximum of the dimensionless figure of merit of 0.16 at 1005 K.

Effect of sintering temperature on structure and properties of Nd2O3 and CeO2 co-doped zeolite waste

Effect of sintering temperature on structural, magnetic, magnetocaloric and critical behaviors of Ni-Cd-Zn ferrites prepared using sol-gel method

The effect of sintering temperature on varistor properties of (Pr, Co, Cr, Y, Al)-doped ZnO ceramics

W-10Ti alloy was prepared by hot press sintering using W-TiH2 powders milled for 24 h under argon atmosphere. The effect of sintering temperature on the phase constituents and the microstructure of the alloys was characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The microhardness of W-rich phase, electrical resistivity and impurity (C, O) contents of W-10Ti alloy were determined. The results show that the amount of W-Ti solid solution, the microhardness of the W-rich solid solution and the resistance of W-10Ti alloy increase with an increase of sintering temperature. At 1300 °C, W-10Ti alloy has the maximum microhardness value of 333 HV0.05, the O content of 360 ppm and C content of 200 ppm.

Gadolinium substitution and sintering temperature dependent electronic properties of Li–Ni ferrite