Microwave Sintering and Electric Properties of ZnO Varistor Ceramics

2013 ◽  
Vol 833 ◽  
pp. 75-79 ◽  
Author(s):  
Xin Xin He ◽  
Guo You Gan ◽  
Ji Kang Yan ◽  
Jing Hong Du ◽  
Jia Ming Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Ball Mill ◽  
Milling Time ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Electric Properties ◽  
Planetary Ball Mill ◽  
Zno Varistor ◽  
C Doping ◽  
Zno Powder

The ZnO varistor ceramics were fabricated through microwave sintering at 800~1150°C using ZnO powder doped and undoped TiO2 prepared by planetary ball mill. And the effects of milling time, sintering temperature and doping on microwave sintering technique have been studied. The result shows that the powder is more homogeneously and with smaller particle size with the increasing of milling time, therefore the electric properties is improved. However the particle size and the electric properties tend towards stability after 20h milling time. The density and electric properties increase with the increasing of sintering temperature, but decrease sharply at 1100°C, so the best sintering temperature is 1100°C. Doping TiO2 improves the electric properties of ZnO, however the electric properties decrease with more than 2.5% doping.

Effect of Milling Time on Particle Size and Surface Morphology of Commercial Zeolite by Planetary Ball Mill

2013 ◽  
Vol 795 ◽  
pp. 711-715 ◽  
Author(s):  
N.Z.F. Mukhtar ◽  
M.Z. Borhan ◽  
Mohamad Rusop ◽  
Saifollah Abdullah
Keyword(s):  
Particle Size ◽  
Ball Milling ◽  
Ball Mill ◽  
Milling Time ◽  
Size Range ◽  
Synthetic Zeolite ◽  
Inorganic Materials ◽  
Planetary Ball Mill ◽  
Dry Grinding ◽  
Particle Sizer

Ball milling is a top down approach and a method to reduce size of particle while Zeolite is a valuable inorganic materials having wide variety of applications. In this paper, ball milling of commercial synthetic Zeolite powder was studied with their time varied. Wet ball milling was selected as a potential means to decrease the particle size of Zeolite over dry grinding. The parameters that included in this study were rotational speed, balls to powder ratio, water to powder ratio and milling time. These nanozeolite were characterized via Zeta-sizer nanoseries of particle sizer, FESEM, and also FTIR. Results showed that commercial synthetic Zeolite powder with particle size larger than 45 μm may be reduced into the size range between 0.2 0.3 μm by planetary ball mill.

Production of Dispersion-Strengthened Cu-TiB2 Alloys by Ball-Milling and Spark-Plasma Sintering

2007 ◽  
Vol 534-536 ◽  
pp. 1489-1492 ◽  
Author(s):  
Dae Hwan Kwon ◽  
Jong Won Kum ◽  
Thuy Dang Nguyen ◽  
Dina V. Dudina ◽  
Pyuck Pa Choi ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Ball Milling ◽  
Spark Plasma Sintering ◽  
Ball Mill ◽  
Milling Time ◽  
Rotation Speed ◽  
Sintering Temperature ◽  
Milled Powder ◽  
Plasma Sintering ◽  
Spark Plasma

Dispersion-strengthened copper with TiB2 was produced by ball-milling and spark plasma sintering (SPS).Ball-milling was performed at a rotation speed of 300rpm for 30 and 60min in Ar atmosphere by using a planetary ball mill (AGO-2). Spark-plasma sintering was carried out at 650°C for 5min under vacuum after mechanical alloying. The hardness of the specimens sintered using powder ball milled for 60min at 300rpm increased from 16.0 to 61.8 HRB than that of specimen using powder mixed with a turbular mixer, while the electrical conductivity varied from 93.40% to 83.34%IACS. In the case of milled powder, hardness increased as milling time increased, while the electrical conductivity decreased. On the other hand, hardness decreased with increasing sintering temperature, but the electrical conductiviey increased slightly

Effect of Process on the Dielectric Properties of BaTiO3-Based X9R Ceramics

2014 ◽  
Vol 906 ◽  
pp. 18-24 ◽  
Author(s):  
Bao Lin Zhang ◽  
Bin Bin Zhang ◽  
Ning Ning Wang ◽  
Jing Ming Fei
Keyword(s):  
Particle Size ◽  
Dielectric Properties ◽  
Milling Time ◽  
Sintering Temperature ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Sintered Ceramic ◽  
X Ray ◽  
Particle Size Analyzer

The effect of milling time and sintering process on the dielectric properties of BaTiO3-based X9R ceramics was investigated. The characterization of the raw powders and the sintered ceramic was carried out by X-ray diffraction and scanning electron microscopy. The particle size distribution of the mixed powders was examined by Laser Particle Size Analyzer. The results shown that with the milling time extended, the Cruie Peak was depressed, or even disappeared. Moreover, with the rise of sintering temperature, the dielectric constant of the ceramics increased and the dielectric loss decreased gradually. Eventually, by milling for 11h and sintering at 1090°Cfor 2h, good dielectric properties were obtained, which were ε25°C≥ 2526, εr/εr25°C≤± 12% (–55~200°C), tanδ≤1.12% (25°C).

Evaluation of particle size reduction and agglomeration in dry grinding of natural quartz in a planetary ball mill

2020 ◽  
Vol 368 ◽  
pp. 149-159 ◽  
Author(s):  
Pedro L. Guzzo ◽  
Filipe B. Marinho de Barros ◽  
Bruno R. Soares ◽  
Juliano B. Santos
Keyword(s):  
Particle Size ◽  
Ball Mill ◽  
Size Reduction ◽  
Planetary Ball Mill ◽  
Natural Quartz ◽  
Particle Size Reduction ◽  
Dry Grinding

scholarly journals Synthesis of Nanocrystalline WC Single-Phase Refractory via Mechanical Milling

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Mansour Razavi ◽  
Mohammad Reza Rahimipour ◽  
Rahim Yazdani-Rad
Keyword(s):  
Mechanical Milling ◽  
Ball Mill ◽  
Single Phase ◽  
Milling Time ◽  
Raw Materials ◽  
Planetary Ball Mill ◽  
Crystalline Size ◽  
Nanometer Scale

In this paper the possibility of production of nanocrystalline WC single-phase by mechanical milling has been investigated. The raw materials containing tungsten and carbon with WC as nucleation were milled in a planetary ball mill and sampled in different times. Studies showed that after 75 hours of milling the WC with W2C was produced and remained constant in higher milling time. Adding WC to raw materials at the beginning process leads to the fact that after 50 hours of milling only WC was synthesized without undesirable W2C phase. This material remained stable until higher times of milling too. From broadening of XRD peaks, the crystalline size in synthesized WC was estimated in nanometer scale which lower than the system containing primary WC, and it means that the strain in this system was lower than first system.

scholarly journals Influence of liberation of sulphide minerals on flotation of sedimentary copper ore

2017 ◽  
Vol 18 ◽  
pp. 01025
Author(s):  
Alicja Bakalarz ◽  
Magdalena Duchnowska ◽  
Andrzej Luszczkiewicz
Keyword(s):  
Particle Size ◽  
Ball Mill ◽  
Milling Time ◽  
Mineral Processing ◽  
Copper Ore ◽  
Sulphide Minerals ◽  
Mineral Liberation ◽  
Mineral Production

Ore liberation is one of the most important parameter in mineral processing, especially in flotation. To separate the valuable components from gangue minerals, it is necessary to liberate one from others. It is achieve primarily through crushing and grinding. These stages are one of the most expensive of mineral production. It is important to determine the adequate mineral liberation which would result in huge savings in the overall cost of flotation plant. The aim of the paper was the analysis of the influence of milling time on the laboratory flotation of the copper ore from stratiform Polish deposit. Three different milling time of copper ore in laboratory ball mill was applied. The flotation results were presented as the recovery-recovery and grade-recovery upgrading curves. The liberation of sulphides and the particle size of sulphides in flotation product were analysed and compared.

scholarly journals The effect of milling time on the alumina phase transformation in the AMCs powder metallurgy reinforced by silica-sand-tailings

2022 ◽  
pp. 103-117
Author(s):  
Sukanto ◽  
Wahyono Suprapto ◽  
Rudy Soenoko ◽  
Yudy Surya Irawan
Keyword(s):  
Particle Size ◽  
Phase Transformation ◽  
Powder Metallurgy ◽  
Mechanical Alloying ◽  
Milling Time ◽  
Sintering Temperature ◽  
Silica Sand ◽  
Second Phase ◽  
The Matrix ◽  
The Impact

This study aims to determine the effect of milling time and sintering temperature parameters on the alumina transformation phase in the manufacture of Aluminium Matrix Composites (AMCs) reinforced by 20 % silica sand tailings using powder metallurgy technology. The matrix and fillers use waste to make the composites more efficient, clean the environment, and increase waste utilization. The milling time applied to the Mechanical Alloying (MA) process was 0.5, 6, 24, 48, and 96 hours, with a ball parameter ratio of 15:1 and a rotation of 93 rpm. Furthermore, hot compaction was carried out using a 100 MPa two-way hydraulic compression machine at a temperature of 300 °C for 20 minutes. The temperature variables of the sintering parameter process were 550, 600 to 650 °C, with a holding time of 10 minutes. Characterization of materials carried out included testing particle size, porosity, X-Ray Diffraction (XRD), SEM-Image, and SEM-EDX. The particle measurement of mechanical alloying processed, using Particle Size Analyzer (PSA) instrument and based on XRD data using the Scherrer equation, showed a relatively similar trend, decreasing particle size occurs when milling time was increased 0.5 to 24 hours. However, when the milling time increases to 48 and 96 hours, the particle size tends to increase slightly, due to cold-weld and agglomeration when the Mechanical Alloying is processed. The impact is the occurrence of the matrix and filler particle pairs in the cold-weld state. So, the results of XRD and SEM-EDX characterization showed a second phase transformation to form alumina compounds at a relatively low sintering temperature of 600 °C after the mechanical alloying process was carried out with a milling time on least 24 hours

The Effect of Milling Time on Physical Properties, Magnetic Properties and Microstructure of Bonded Magnet BaFe12O19

2020 ◽  
Vol 855 ◽  
pp. 34-39
Author(s):  
Suprapedi ◽  
Muljadi ◽  
Priyo Sardjono ◽  
Ramlan Ramlan
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Particle Size Distribution ◽  
Physical Properties ◽  
Bulk Density ◽  
Ball Mill ◽  
Milling Time ◽  
Mixed Powder ◽  
Bonded Magnet

A bonded permanent magnet of Barium hexa Ferrite has been made using powder BaFe12O19 (commercial ferrite) and a polymer of bakelite powder as binder. The composition of bakelite was varried 5% wt. The preparation of sample was begun with mass weighing for each material, then mixed together using ball mill for 1, 6 and 12 hours and using aquades as milling media. The mixed powder is dried in an oven at 110 °C for 4 hours, then the particle size distribution was measured. After that, the dried sample powder was pressed to form a pellet at pressure 40 MPa and temperature about 160 °C for 20 minutes. The characterization of sample pellet was done such as measurement of bulk density, hardness , magnetic properties using VSM and anylisis of microstructure using SEM. The results of the characterization show that the density and magnetic properties tend to increase with increasing of milling time, where the highest density, hardness and highest magnetic properties are achieved at sample with milling time for 12 hours. The value of magnetic properties at this condition are flux magnetic of 530 Gauss, remenance of 3100 Gauss, coercivity of 1,10 kOe.

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