egum et al, Material ci Enga, Journal of Material ...
by ball milling with Zirconia (ZrO 2) balls in an ethanol media. 10% solution of PVA binder was produced and was added to the slurry during the ball milling process. The prepared slurry was sieved and dried in an oven at 60°C for 24 hrs. The dried powder was grinded and sieved. Cylindrical discs of 20 mm diameter were prepared by Abstract
Influence of Annealing Atmosphere on Varistor Property of ...
structure and the varistor properties of TiO 2-Nb 2 O 5-SrCO 3 ceramics was studied. 2. Material and Methods Table 1 shows the initial doping contents of each sample. The mixture was grinded in a planetary ball mill to obtain the reactants. The purity of each rea-gent is as follows: TiO 2 (powder, 99.9%), Nb 2 O 5 (powder, 99.9%), SrCO 3 (powd ...
Varistor properties of TiO2–Ta2O5–CaCO3 ceramics doped ...
Varistor properties of TiO2–Ta2O5–CaCO3 ceramics doped with GeO2. This study investigates the influence of GeO2 on the nonlinear coefficient (α) and breakdown voltage (EB) of TiO2–Ta2O5–CaCO3 varistor ceramics doped with GeO2 and prepared according to a conventional ball milling–molding–sintering process.
Reaction Bonding of Zinc Oxide (RBZO) to Produce ZnO-Based ...
A reaction bonding process was applied to produce ZnO-based varistor formulations. Starting materials were metallic powders of Zn, Co, Mn, Cr and Sb mixed with ZnO and Bi2O3 powders. Differential thermal analysis indicates that complete Zn oxidation occurs at temperatures above 419°C that correspond to the melting point of Zn.
(PDF) Effect of Cr 2 O 3 in the varistor behaviour of TiO ...
Varistors a = 9.5 without an oxidizing atmosphere [12]. based on SiC have low non-linearity coefficients In this letter, the processing of a single phase (a = 5), where a is the non-linearity constant Cr203- and Nb2Os-doped TiO2 system as well as the defined by the relation I = K V ~ where I is the electrical behaviour (current densities as ...
Optimization of Bi2O3, TiO2, and Sb2O3 Doped ZnO-Based Low ...
2.1. Sample Preparation. The samples were fabricated using a conventional ceramic process with nominal composition of ZnO (99.99%), Bi 2 O 3 (99.975%), Sb 2 O 3 (99.6%), and TiO 2 (99.9%) as raw powders. The raw chemicals of analytical grade produced by Alfa Aesar were weighed according to the experimental designs (Table 2) based on molar ratio [mol%].The molar ratio was converted into …
Chemical bonding black phosphorus with TiO2 and carbon ...
Phosphorus (P)-based materials are recognized as one type of prospective candidate anodes due to its high theoretical capacities. However, it still suffers the relatively low structural stability and rate performance. In the present work, an amorphous ternary black Phosphorus (BP)- Titanium dioxide (TiO2)- Carbon (C) nanocomposite is fabricated by a facile ball milling process, which can serve ...
Optimizing Bi2O3 and TiO2 to achieve the maximum non ...
Abstract. BACKGROUND: In fabrication of ZnO-based low voltage varistor, Bi2O3 and TiO2 have been used as former and grain growth enhancer factors respectively. Therefore, the molar ratio of the factors is quit important in the fabrication. In this paper, modeling and optimization of Bi2O3 and TiO2 was carried out by response surface methodology ...
US3842018A - Oxide varistor composition consisting of zno ...
1. an oxide varistor comprising a basic composition (totaling 100 mol percent) consisting of 87 to 12 mol percent of zno, 1 to 30 mol percent of antimony oxide selected from the group consisting of sb2o3, sb2o5 and a mixture thereof and 12 to 87 mol percent of at least one metal oxide selected from the group consisting of zro2, tio2 and geo2, and an additive consisting of of 0.5 to 10% by ...
Mechanical Milling: a Top Down Approach for the Synthesis ...
In that work we employed a two-step process; 1) ball milling of silicon, and 2) spray pyrolysis of ball milled silicon in hexane at 1000± 1100℃ in an argon atmosphere. Silicon powder (99.99 %, particle size 0.05mm) was ball-milled in an attritor ball-mill at 400 rpm for 30 h in hexane.
Qun Qin | Scientific.Net
The nonlinear current (I)-voltage (V) characteristics of TiO2 are examined when doped with small quantities (0.1-0.9 mol%) of CeO2. It is found that CeO2 affects the electrical properties and the dielectric properties of the TiO2-based varistors.
(PDF) Synthesis of iron-doped TiO2 nanoparticles by ball ...
The milling process at 400 rpm for 4 hours showed significant reduction of the particle size of TiO2 from 1595.4 ± 73.4 nm to be 358.9 ± 41.0 nm, which were comparable to the size of commercial ...
Journal of Asian Ceramic Societies, /, - X-MOL
ABSTRACT Ball milling (BM) is utilized to fabricate a composite photocatalyst composed of g-C3N4 material and ZnPc, which traditionally has been a sensitizer in TiO2 based solar cells yet usually having severe agglomeration problem.
Ge-added TiO2–Ta2O5–CaCO3 varistor ceramics - ScienceDirect
The influence of doping with Ge on the nonlinear coefficient α and the breakdown electric field E B of TiO 2 –Ta 2 O 5 –CaCO 3 varistor ceramics was investigated. In this study, TiO 2 –Ta 2 O 5 –CaCO 3 varistor ceramics added with Ge was successfully prepared using the traditional method of ball milling–molding–sintering. The electrical performance, including the nonlinear ...
Facile fabrication of ZnPc sensitized g-C3N4 through ball ...
ABSTRACT Ball milling (BM) is utilized to fabricate a composite photocatalyst composed of g-C3N4 material and ZnPc, which traditionally has been a sensitizer in TiO2 based solar cells yet usually having severe agglomeration problem. X-ray diffraction and FTIR results demonstrate that ZnPc has been immobilized onto g-C3N4 surfaces and that the inter-molecular bonds were also destroyed to a ...
The mechanical milling of Al/TiO2 composite powders ...
The processing of Al/TiO2 composite powders produced by high-energy mechanical milling leads to production of a range of valuable, titanium-based materials. They include Ti(Al,O)/Al2O3 and TixAly(O)/Al2O3 composite powders, bulk composites and Ti3Al/TiAl alloy powders, and corresponding bulk materials. The strength of the Ti(Al,O)/Al2O3 and TixAly(O)/Al2O3 composites is moderate, but …
High-Energy Ball Milling - 1st Edition
Purchase High-Energy Ball Milling - 1st Edition. Print Book & E-Book. ISBN 9781845695316, 9781845699444
High energy ball milling process for nanomaterial synthesis
In our research, we use the high-energy ball milling technique to synthesize various nanometer powders with an average particle size down to several nm, including nano-sized a-Fe 2 O 3 based solid solutions mixed with varied mole percentages of SnO 2, ZrO 2 and TiO 2 separately for ethanol gas sensing application, stabilized ZrO 2 based and TiO ...
US6620346B1 - Varistors based on nanocrystalline powders ...
The invention concerns novel varistors based on zinc oxide and a method for making same, which consists in using as base products nanocrystalline powders obtained by high-intensity mechanical grinding and in subjecting the mixture resulting from said nanocrystalline powders a consolidating treatment such as sintering, in suitably selected temperature and time conditions so as to retain the ...
Novel TiO2·WO3 varistor system - ResearchGate
Based on the single sinter process, five disk samples of (Sr, Bi, Si, Ta)-doped TiO2-based varistor ceramics, which were sintered separately at the temperature of 1200–1400°C for 2.5h, were ...
VWHP - Institute of Physics
Ti02 used was spectral grade. Varistors were ob- tained by conventional ceramic processing. Powders were achieved by ZrOz-ball milling process for 12 h, then the powders were pressed at 180 MPa into pellet shapes (15" in diameter by 1.0" in thickness). The samples were sintered in air at 140OOC for 1 h
(PDF) Structural evolutions in Ti and TiO2 powders by ball ...
The variation in crystallite size and lattice strain as a function of milling TiO2 rutile and hcp–TiO phases as a function of milling time. time for (a) the TiO2 rutile phase and (b) the hcp–TiO phase. During ball milling process, the powder particles were subjected to severe mechanical deformation from high-energy collisions.
Electric and dielectric behaviors of (Ca, Ta)-doped TiO2 ...
In the current study, TiO 2-based thick film varistors (TFVs) doped with 2.5 mol% Ta and various concentrations of Ca were prepared by using screen- technique.The effects of the different Ca concentrations (0.5–3.0 mol%) on microstructure enhancement, nonlinear behavior, and dielectric properties of TiO 2-based TFVs were investigated at 2.0 mol% doping concentration.
Synthesis of iron-doped TiO2 nanoparticles by ball-milling ...
In a ball-milling process, powders are plastically deformed due to the high-energy impact between balls and the wall of the vial. The result is the rise of the local temperature and pressure (up to several GPa) at the collisions sites of the powder and the balls [ 19 ], and in some cases the production of fresh surfaces by fracture of material ...
Optimizing Bi2O3 and TiO2 to achieve the maximum non ...
Background. In fabrication of ZnO-based low voltage varistor, Bi 2 O 3 and TiO 2 have been used as former and grain growth enhancer factors respectively. Therefore, the molar ratio of the factors is quit important in the fabrication. In this paper, modeling and optimization of Bi 2 O 3 and TiO 2 was carried out by response surface methodology to achieve maximized electrical properties.
US6743381B2 - Process for forming varistor ink composition ...
US6743381B2 US09/946,294 US94629401A US6743381B2 US 6743381 B2 US6743381 B2 US 6743381B2 US 94629401 A US94629401 A US 94629401A US 6743381 B2 US6743381 B2 US 6743381B2 Authority
Effect of ball milling on reaction between TiO2 and Al ...
Titanium Aluminide based composites with Al2O3 reinforcement can be produced via reaction of Al with TiO2. These composites are considered as low price materials for high temperature applications. In this research, the effect of ball milling on 3TiO2/7Al system was investigated. On the basis of obtained results, ball milling for 0 to 60 h does not lead to reduction of TiO2 by Al. but reduces ...
STUDY OF THE EFFECT OF WO3 AND Bi2O3 ON THE …
The powders were mixed by ball milling where ethanol was used as a solvent. The process was then followed by drying the slurry at 600C for 24 hours and was then followed by sieving. The green powder was then compacted using a hydraulic press machine with 2.76MPa into a disc of 20mm diameter. These green pellets were sintered
Effects of Eu2O3 doping on microstructural and electronic ...
ZnO-Bi2O3-based varistor ceramics doped with Eu2O3 in a range from 0 to 0.4% were obtained by high-energy ball milling and fired at 900–1 000 °C for 2 h. XRD and SEM were applied to determine the phases and microstructure of the varistor ceramics. A DC parameter instrument was applied to investigate the electronic properties and V-I characteristics. The XRD analysis of Eu2O3 …
The Microstructure and Electrical Behavior of TiO2 ...
A comparative study of the microstructures of two kinds of TiO2 based varistor materials processed from the slurry using magnetized water and regular deionized water is conducted. The additives in the form of oxides of Nb, Ce, Ca, and Si were used in the recipe. The electrical behavior reveals that the water magnetized at 0.2 T yielded lower varistor voltage while the water magnetized …