The Effects of Sintering Temperature on the Properties of Mg-Mn-Zn Ferrites

2013 ◽  
Vol 680 ◽  
pp. 31-34 ◽  
Author(s):  
Ji Wei Fan ◽  
Wen Qing Li ◽  
Hui Jun Zhao ◽  
Xiao Li Zhang ◽  
Zhen Guo Zhang

The present work shows the results of investigation on the effects of sintering temperatures of (Mg0.25Mn0.1Zn0.65)Fe2O4 ferrite on its sintered density, initial permeabilty, resistivity and microstructure. To achieve better sintered density and initial permeabilty, the sintering temperature should be ≥1200oC. However, the higher sintering temperature results in larger the grain size, which causes the reduction of the resistivities of Mg-Mn-Zn ferrites. Furthermore, the resistivities of samples are environmental temperature sensitive, and possibly possess the similar function of NTC thermistor over the testing range 25-225oC.

2009 ◽  
Vol 6 ◽  
pp. 115-122 ◽  
Author(s):  
Dachamir Hotza ◽  
Adrian Leo ◽  
Jaka Sunarso ◽  
João C. Diniz da Costa

This work investigates the effect of nanosized Al2O3 addition on the sinterability of YSZ electrolyte. (1−x)YSZ + Al2O3 ceramics with compositions x = 0 to 0.01 were prepared by the conventional mixed oxide route from a commercial powder suspension (particle size <50 nm), and sintered at 1200 to 1500°C for 2 hours in air. Densification, phase evolution, and microstructure were characterized by SEM/EDS and XRD. An improvement in sintered density was observed for the samples with 0.2 to 0.5 mol% Al2O3, though depending on the sintering temperature. Only cubic zirconia was detected as crystalline phase, although XRD features suggested chemical interactions depending upon the amount of Al2O3. The grain size of YSZ was homogeneous and no second phase segregation was detected in the tested range of incorporated nano-Al2O3 and sintering temperatures.


2012 ◽  
Vol 217-219 ◽  
pp. 483-486
Author(s):  
Mei Yuan Ke

Effects of Sintering atmosphere and temperature on properties of warm compacted 410L stainless steel powder were studied. Sintered density, hardness, tensile strength and elongation were measured. Results showed that in order to achieve high comprehensive properties, the optimal sintering temperature was 1230°C for 410L stainless steel powder. At the same sintering temperature, density and hardness sintered in vacuum were much higher than that sintered in cracked ammonia while tensile strength sintered in cracked ammonia were much higher than that in vacuum. When sintered in vacuum at 1230°C, sintered density was 7.45 g•cm-3, hardness was 65 HRB, tensile strength was 410 MPa and elongation was 29.5%. When sintered in cracked ammonia atmosphere at 1230°C, sintered density was 7.26 g•cm-3, hardness was 97 HRB, tensile strength was 515 MPa and elongation was 3.8%.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Xianjie Yuan ◽  
Xuanhui Qu ◽  
Haiqing Yin ◽  
Zaiqiang Feng ◽  
Mingqi Tang ◽  
...  

This present work investigates the effects of sintering temperature on densification, mechanical properties and microstructure of Al-based alloy pressed by high-velocity compaction. The green samples were heated under the flow of high pure (99.99 wt%) N2. The heating rate was 4 °C/min before 315 °C. For reducing the residual stress, the samples were isothermally held for one h. Then, the specimens were respectively heated at the rate of 10 °C/min to the temperature between 540 °C and 700 °C, held for one h, and then furnace-cooled to the room temperature. Results indicate that when the sintered temperature was 640 °C, both the sintered density and mechanical properties was optimum. Differential Scanning Calorimetry, X-ray diffraction of sintered samples, Scanning Electron Microscopy, Energy Dispersive Spectroscopy, and Transmission Electron Microscope were used to analyse the microstructure and phases.


2012 ◽  
Vol 17 (1) ◽  
pp. 269-274 ◽  
Author(s):  
Bogna Stawarczyk ◽  
Mutlu Özcan ◽  
Lubica Hallmann ◽  
Andreas Ender ◽  
Albert Mehl ◽  
...  

2014 ◽  
Vol 616 ◽  
pp. 157-165 ◽  
Author(s):  
Chang Lian Chen ◽  
Hong Quan Wang ◽  
Jia You Ji ◽  
Ma Ya Luo ◽  
Bo Wu ◽  
...  

In this paper, using ZrO2 and Ca (NO3)•4H2O as raw materials, we prepared a series of calica stabilized zirconia (CSZ) ceramics by pressureless sintering method. The results show that the relative densities of all sintered samples are above 90%, and the sintered samples are composed of cubic, tetragonal and monoclinic ZrO2, and the main phase is cubic ZrO2 and tetragonal ZrO2. The content of cubic phase increases with the increase of sintering temperature and adding CaO content. The grain size of the sintered samples is relatively uniform and some pores exist. Increasing the additive amount of CaO, the conductivity first rises and then decreases, and the conductivity value of the sample containing 5wt% CaO is the maximum. When the sintering temperature is up to 1600 oC, the conductivity of the sample containing 5wt% CaO is up to 0.016S•cm-1 at 800 oC. Furthermore, the conductivity of sintered samples is increasing with the increase of test temperature according to the Arrhenius equation.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bambar Davaasuren ◽  
Qianli Ma ◽  
Alexandra von der Heiden ◽  
Frank Tietz

Abstract Li1.5Al0.5Ti1.5(PO4)3 (LATP) powders were prepared from different NO x -free precursors using an aqueous-based solution-assisted solid-state reaction (SA-SSR). The sintering behavior, phase formation, microstructure and ionic conductivity of the powders were explored as a function of sintering temperature. The powders showed a relatively narrow temperature windows in which shrinkage occurred. Relative densities of 95% were reached upon heating between 900 and 960 °C. Depending on the morphological features of the primary particles, either homogeneous and intact microstructures with fine grains of about <2 µm in size or a broad grain size distribution, micro-cracks and grain cleavages were obtained, indicating the instability of the microstructure. Consequently, the ceramics with a homogeneous microstructure possessed a maximum total ionic conductivity of 0.67 mS cm−1, whereas other ceramics reached only 0.58 mS cm−1 and 0.21 mS cm−1.


2014 ◽  
Vol 895 ◽  
pp. 319-322
Author(s):  
Lim Kean Pah ◽  
Abdul Halim Shaari ◽  
Chen Soo Kien ◽  
Chin Hui Wei ◽  
Albert Gan ◽  
...  

In this work, we report the effect of sintering temperature (900°C, 1000°C, 1100°C and 1200°C) on the electrical and magnetotransport properties of polycrystalline La0.67Sr0.33MnO3 (LSMO). Single phase of LSMO hexagonal structure (R-3c) accompanied with minor phases was successfully synthesized by co-precipitation method. With increasing sintering temperature, grain growth was promoted and grain connectivity was improved. It was found that an enhancement of resistivity on smaller grain size was due to larger grain surface over volume (grain boundaries effect). The shifting of the metal-insulator transition (TMI) to higher temperature was also responsible for observed changes in physical properties. TMI of 900°C, 1000°C and 1100°C were 232 K, 278 K and 298 K respectively however 1200°C was out of measurement range (higher than 300 K). In summary, CP900 with smaller grain size distribution (~200 nm) displayed the highest resistivity and MR% of -19.2% (at 80 K, 10 kG).


2007 ◽  
Vol 22 (5) ◽  
pp. 1200-1206 ◽  
Author(s):  
R. Malewar ◽  
K.S. Kumar ◽  
B.S. Murty ◽  
B. Sarma ◽  
S.K. Pabi

The present investigation reports for the first time a dramatic decrease in the sintering temperature of elemental W from the conventional temperature of ≥2500 °C to the modest temperature range of 1700–1790 °C by making the W powder nanostructured through high-energy mechanical milling (MM) prior to sintering. The crystallite size of the initial W powder charge with a particle size of 3–4 μm could be brought down to 8 nm by MM for 5 h in WC grinding media. Further milling resulted in a high level of WC contamination, which apparently was due to work hardening and the grain refinement of W. A sintered density as high as 97.4% was achieved by sintering cold, isostatically pressed nanocrystalline (8 nm) W powder at 1790 °C for 900 min. The microstructure of the sintered rods showed the presence of deformation bands, but no cracks, within a large number of W grains. The mechanical properties, when compared with the hardness and elastic modulus, of the sintered nano-W specimen were somewhat superior to those reported for the conventional sintered W.


2007 ◽  
Vol 26-28 ◽  
pp. 243-246
Author(s):  
Xing Hua Yang ◽  
Jin Liang Huang ◽  
Xiao Wang ◽  
Chun Wei Cui

BaBi4-xLaxTi4O15 (BBLT) ceramics were prepared by conventional solid phase sintering ceramics processing technology. The crystal structure and the microstructure were detected by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD analyses show that La3+ ions doping did not change the crystal structure of BBT ceramics. The sintering temperature increased from 1120°C to 1150°C with increasing Lanthanum content from 0 to 0.5, but it widened the sintering temperature range from 20°C to 50°C and refined the grain size of the BBT ceramic. Additionally, polarization treatment was performed and finally piezoelectric property was measured. As a result, the piezoelectric constant d33 of the 0.1at.% doped BBLT ceramics reached its highest value about 22pc/N at polarizing electric field of 8kV/mm and polarizing temperature of 120°C for 30min.


2011 ◽  
Vol 25 (19) ◽  
pp. 2583-2591 ◽  
Author(s):  
A. TAWFIK ◽  
M. Z. SAID ◽  
O. M. HEMEDA

The systems MgCuZn Fe 2 O 4 doped (0–0.6 wt% Ta) are prepared by the general ceramic method using the sintering temperature at 1200°C. The variations of the sintered density, lattice parameter, jump length of electrons, and initial permeability were studied. A maximum density was obtained at 1200°C during the preparation process. The electrical resistivity decreases with increasing tantalum ( Ta ) content upto 0.1 wt% and then increases for higher concentrations. The initial permeability and the change carries mobility increase upto 0.1 Ta and then decreases. The jump length decreases with enhancing Ta ions because the substitution of Ta ion with small size instead of Fe 3+ at the A sites increase the concentration of iron ions at the B sites. The increase of the iron content causes the decrease of the jump length of electrons between Fe 3+ and Fe 2+. These improvements of the magnetic properties give some light about the importance of these compositions to be used in technology.


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