Effect of Sintering Process on Microstructures and Dielectric Properties of Nb-Doped BaTiO3-(Bi0.5Na0.5)TiO3 Ceramics for X9R MLCC Applications

2018 ◽  
Vol 281 ◽  
pp. 634-639
Author(s):  
Ling Ling Chen ◽  
Zheng Bo Shen ◽  
Qian Cheng Zhao ◽  
Zi Ming Cai ◽  
Xiao Hui Wang ◽  
...  
Keyword(s):  
Screen Printing ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Tape Casting ◽  
Sintering Process ◽  
Ceramic Capacitor ◽  
Conventional Sintering ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Sintering Method

Multilayer ceramic capacitor (MLCC) chips have been successfully prepared through tape-casting and screen-printing. Conventional sintering method and two-step sintering method with different sintering temperature and holding time are used to obtain the MLCC chips. The scanning electron microscopes show that MLCC chips sintered by two-step sintering at T1=1200°C and T2=1130°C for 3h have a highly dense dielectric layer. The temperature coefficient of capacitance (TCC) of the MLCC chip is less than ±15% from-60°C to 235 °C that satisfactorily meets the requirement of X9R. The average capacitance and the dielectric loss of the MLCC chip are 88nF and 1.8% at the room temperature, respectively.

scholarly journals Processing Analysis of Nanoparticle Filled PTFE: Restrictions and Limitations of High Temperature Production

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2044
Author(s):  
Levente Ferenc Tóth ◽  
Patrick De Baets ◽  
Gábor Szebényi
Keyword(s):  
Thermal Stability ◽  
Mass Loss ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Research Work ◽  
Decomposition Analysis ◽  
High Thermal Stability ◽  
Al2o3 Content ◽  
Sintering Process ◽  
Sintering Method

In this research work, unfilled and monofilled polytetrafluoroethylene (PTFE) were investigated. The applied fillers were graphene, alumina (Al2O3), boehmite alumina (BA80) and hydrotalcite (MG70). Graphene and Al2O3 are already known in the literature as potential fillers of PTFE, while BA80 and MG70 are novel fillers in PTFE. Materials were produced by room temperature pressing—free sintering method with a maximum sintering temperature of 370 °C. The mass loss and decomposition analyses were carried out by thermogravimetric analysis (TGA) in two different ways. The first was a sensitivity analysis to gain a better view into the sintering process at 370 °C maximal temperature. The second was a heating from 50 °C up to 1000 °C for a full-scale decomposition analysis. BA80 is a suitable filler for PTFE, as most of its functional groups still existed after the sintering process. Both PTFE and Al2O3 had high thermal stability. However, when Al2O3 was incorporated in PTFE, a remarkable mass loss was observed during the sintering process, which indicated that the decomposition of PTFE was catalysed by the Al2O3 filler. The observed mass loss of the Al2O3-filled PTFE was increased, as the Al2O3 content or the applied dwelling time at a 370 °C sintering temperature increased.

Preparation and Electrical Properties of Dense Bi4Ti3O12 Ceramics by Spark Plasma Sintering

2007 ◽  
Vol 280-283 ◽  
pp. 141-144
Author(s):  
Jun Jie Hao ◽  
Xiao Hui Wang ◽  
Long Tu Li ◽  
Zhi Lun Gui
Keyword(s):  
Electrical Properties ◽  
Spark Plasma Sintering ◽  
Electronic Materials ◽  
Sintering Temperature ◽  
Sintering Process ◽  
Plasma Sintering ◽  
The Family ◽  
Conventional Sintering ◽  
Spark Plasma ◽  
Sintering Method

The family of bismuth layer-structured ferroelectrics is attractive from the viewpoint of their application as electronic materials such as dielectrics, piezoelectrics and pyroelectrics. However, during conventional sintering method, high sintering temperature and long sintering time were needed and it is difficult to get BIT ceramic with a density more than 95% of its theoretic value. In the present paper, we produce dense BIT pellet using a spark plasma sintering process. The results show that at a sintering temperature as low as 7000C/5min under a pressure of 25MPa, BIT ceramics with a density about 99% of its theoretic can be produced. The densities, grain size and electrical properties of the resulting ceramic were also investigated.

Effect of Sintering Temperature on Properties of YAG Porous Ceramics via Atmospheric Sintering Method

2018 ◽  
Vol 281 ◽  
pp. 224-229 ◽  
Author(s):  
Fang Wang ◽  
Ming Han Xu ◽  
Ai Xia Chen ◽  
Long Tao Liu ◽  
Zhi Hui Li ◽  
...  
Keyword(s):  
Sintering Temperature ◽  
Raw Materials ◽  
Porous Ceramics ◽  
Soluble Starch ◽  
Product Performance ◽  
Effect Of Temperature ◽  
Sintering Process ◽  
Molding Process ◽  
Sintering Aid ◽  
Sintering Method

YAG materials have a number of unique properties, the application is very extensive, the burn is due to the temperature is too high or the residence time at high temperatures is caused. The undercurrent is the sintering temperature is too low or the holding time is not enough, resulting in product performance is too low or too small shrinkage. In this paper, the effect of sintering temperature on properties of YAG porous ceramics was investigated. The results showed that the firing temperature of the ingredients will be different and cause the same sintering process and sintering additives content of different samples burned. The increase in the content of SiO2 in the furnish with the sintering aid tends to occur. the effect of temperature on the mechanical properties of the samples after sintering was significant, so the raw materials include 60wt%YAG, 10wt% CaO, 10wt% SiO2 and 20wt% soluble starch, the molding process in 20MPa pressure 10min, the sintering at 1500°C for 2h, the sample porosity is 42.2%, the compressive strength is 5.8MPa, the outside shape is keep intact and the better pore microstructure is shown.

PHASE STRUCTURE, PIEZOELECTRIC AND MULTIFERRIOC BEHAVIOR OF (K0.48Na0.52)NbO3-Co2O3 PIEZOELECTRIC CERAMICS

2011 ◽  
Vol 04 (03) ◽  
pp. 225-229 ◽  
Author(s):  
WENJUAN WU ◽  
DINGQUAN XIAO ◽  
JIAGANG WU ◽  
JING LI ◽  
JIANGUO ZHU
Keyword(s):  
Room Temperature ◽  
Sintering Temperature ◽  
Magnetic Behavior ◽  
Orthorhombic Phase ◽  
Piezoelectric Ceramics ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Solid State Sintering ◽  
Sintering Method

( K 0.48 Na 0.52) NbO 3-x% Co 2 O 3 (x = 0, 0.03 and 0.05) (KNN-x% Co2O3 ) lead-free piezoelectric ceramics were prepared by the conventional solid-state sintering method. An orthorhombic phase was observed for all KNN-x% Co2O3 ceramics at room temperature, and two phase transitions were confirmed by the high temperature X-ray diffraction and the temperature dependence of the dielectric constant. The Co2O3 greatly improves the density and decreases the sintering temperature of KNN ceramics. The KNN-0.05 mol%Co2O3 ceramic exhibits good properties (d33 = 120 pC/N , k p = 0.41, Q m = 213 and T c = 407°C) and a good age stability. The multiferroic behavior was also observed at room temperature for the KNN-0.05 mol%Co2O3 ceramic, as confirmed by P–E loops and magnetic behavior.

Electromechanical Properties of NKN-5LT Multilayer Actuator

2007 ◽  
Vol 26-28 ◽  
pp. 263-266 ◽  
Author(s):  
Min Soo Kim ◽  
Soon Jong Jeong ◽  
Jae Sung Song
Keyword(s):  
Electromechanical Coupling ◽  
Tape Casting ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Electromechanical Properties ◽  
Wide Range ◽  
Conventional Sintering ◽  
Mechanical Transducer ◽  
Multilayer Actuator ◽  
Sintering Method

Li2O excess 0.95(Na0.5K0.5)NbO3-0.05LiTaO3 (NKN-5LT) ceramics were developed by conventional sintering method. Abnormal grain growth in NKN-5LT ceramics was observed with varying Li2O content during sintering. In the 1 mol% Li2O excess NKN-5LT samples sintered at 1000 oC for 4h in air, electromechanical coupling factor and piezoelectric constant of NKN-5LT ceramics were found to reach the highest values of 0.37 and 250 pC/N, respectively. Lead-free piezoelectric of the composition 1 mol% Li2O excess NKN-5LT were fabricated. 10×10×3 mm3 size multilayer ceramic actuators (MLCA) were fabricated by conventional tape casting method. The displacement of the MLCA was ~ 1 μm at 150 V. These results show that the NKN-5LT ceramics with reasonable good piezoelectric properties have the potential to become the next generation material for a wide range of electro-mechanical transducer applications.

Densification Behavior of Steatite by Two Stage Sintering

2012 ◽  
Vol 488-489 ◽  
pp. 194-201
Author(s):  
C.K.L. Jeffrey ◽  
S. Ramesh ◽  
C.Y. Tan
Keyword(s):  
Bulk Density ◽  
Room Temperature ◽  
Dense Body ◽  
Cost Effective ◽  
Densification Behavior ◽  
Two Stage ◽  
Performance Requirements ◽  
Engineering Ceramic ◽  
Conventional Sintering ◽  
Sintering Method

Structural materials, such as steatite-based ceramic is considered one of the most useful engineering ceramic in place of alumina as a cost-effective way to meet performance requirements. The objective of the research here is to develop a dense body which exhibits good properties as mentioned by the two stage sintering method. Steatite powders used in this work were undoped steatite, steatite doped 20wt% ZnO and steatite doped 20wt% MnO2. The green samples were cold-isostatically pressed and pressureless sintered at temperatures ranging from 950°C to 1200°C at heating rate of 10°C/min through two stage sintering before cooling down to room temperature. The results revealed an improvement in the densification of all the steatites through two stage sintering compared to the conventional sintering. At 1200°C, the steatite bodies with 20 wt% ZnO compositions achieved maximum bulk density of 2.79 g/cm3 which is 10.3% higher than the same steatite doped bodies which exhibited best result when it was conventionally sintered. As a result of bulk density improvement, two stage sintering exhibited outstanding effects in enhancing Young’s modulus and hardness of the steatite body.

Mechanical Properties of SiC/FexSiy Composites

2011 ◽  
Vol 236-238 ◽  
pp. 1523-1527 ◽  
Author(s):  
Xiao Meng Zhang ◽  
Shu Feng Ye ◽  
Li Hua Xu ◽  
Peng Qian ◽  
Lian Qi Wei ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Flexural Strength ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Raw Material ◽  
Reaction Sintering ◽  
Sintering Process ◽  
Scanning Electron

The SiC/FexSiycomposites were synthesized by reaction sintering process with iron tailings as raw material and carbon as reductant. The room and high temperature flexural strengths and fracture toughness of composites were studied in this paper. Fracture surfaces were observed by means of a scanning electron microscope (SEM). The results showed that the room temperature flexural strength of SiC/FexSiycomposites changed along with the different contents of FexSiyand sintering temperature. The flexural strength of composites reaches the maximum at 900°C. The correlation between flexural strength and temperature is consistent with curveⅠ.The fracture toughness of composites is related to the content of FexSiy. The fracture behavior of composites is mainly transcrystalline in room temperature and intercrystalline in high temperature.

Study of Mechanical Properties of Magnesium Oxide Doped Alumina (Al2O3) and Yttria Stabilized Zirconia (YSZ) Composite for Medical Applications

2012 ◽  
Vol 506 ◽  
pp. 521-524 ◽  
Author(s):  
A. Phothawan ◽  
K. Nganvongpanit ◽  
T. Tunkasiri ◽  
Sukum Eitssayeam
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Magnesium Oxide ◽  
Sintering Temperature ◽  
The Body ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Electron Microscopes ◽  
Pin On Disk ◽  
Scanning Electron Microscopes

The aim of this research is to study the mechanical properties such as hardness ,wear resistance etc , of the magnesium oxide (MgO) doped alumina (Al2O3) and yttria stabilized zirconia (YSZ) composite, We first prepared MgO-doped Al2O3(denoted as Al4) by mixing Al2O3powder and 0.4 wt% of MgO powder. After that Al4powder was mixed YSZ powder, with the formula [(x)Al4- (100-x)YS when x was varied from 0 - 100 by wt%. The samples were sintered at 1450, 1500, 1550, 1600 and 1650 °C. In addition, microstructure of the surface was studied employing both optical and scanning electron microscopes. The hardness of the surface was investigated by Vickers indentation technique and pin on disk apparatus was employed for wear rate measurement. The results showed that the density and volume shrinkage decreased with the increase of Al4content. The grain size and porosity of the specimens tend to decrease when the sintering temperature increases. The hardness and wear resistance of the samples increased with the increase of Al4up to 90 %. It was also found that the material is not toxic to the body.

Preparation of Rare-Earth Permanent Magnetic Strontium Ferrite by Microwave Sintering Process

2010 ◽  
Vol 177 ◽  
pp. 264-268 ◽  
Author(s):  
Han Han Jiang ◽  
Ming Lin Jin ◽  
Zhan Yong Wang ◽  
Qi Zhong Chen ◽  
Hui Chun Qian
Keyword(s):  
Rare Earth ◽  
Microwave Sintering ◽  
Magnetic Domain ◽  
Strontium Ferrite ◽  
Green Body ◽  
Sintering Process ◽  
Wet Milling ◽  
Conventional Sintering ◽  
Degree Of Orientation ◽  
Sintering Method

In this paper, the green body was prepared by pre-roasted material of strontium ferrite, adding 0.2 to 9% the rare earth additive, by wet milling and forming into pellets Φ30×10 mm under magnetic field. Then, the green body was sintered separately by microwave sintering (MS) method and conventional sintering (CS) technique. The results showed that: the strontium ferrite samples with the same magnetic properties Br and (BH) max were 420 ± 10mT and 33.0 ± 2 kJ/m 3) were synthesized by microwave sintering (MS) method against conventional sintering method, the sintering temperature and time were reduced 150~300°C and 5~6h. Therefore, microwave sintering method will significantly decrease energy consumption. Further analysis revealed that the major improvements in microwave sintering were the material microstructure, the grain size was significantly reduced, the magnetic domain short-range order was increased so that the degree of orientation was increased, and although the fusion was existed between grains, the grain boundaries did not disappear.

scholarly journals FABRICATION AND CHARACTERISATION OF MG-ZN ALLOYS REINFORCED WITH CNF: A STUDY ON THE SINTERING PROCESS

2020 ◽  
Vol 83 (1) ◽  
pp. 1-6
Author(s):  
Herman Tuminoh ◽  
Muhammad Sallehuddin Mohd Azman ◽  
Muhammad Al Kahfi Edrus ◽  
Ahmad Kafrawi Nasution ◽  
Muhammad Hanif Ramlee
Keyword(s):  
Ball Mill ◽  
Gas Flow ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Biodegradable Implants ◽  
Sintering Process ◽  
Mechanically Alloyed ◽  
Carbon Nanofibres ◽  
Potential Use ◽  
Zn Alloys

Nowadays, magnesium (Mg) based alloys have gained much interest due to its potential use as biodegradable implants for the application of fixation, screws and plates in orthopaedics field. The main problems of biodegradable implants made from pure Mg are its low strength and easily corrodible. Therefore, the purpose of this study was to analyse the sintering temperature of magnesium-zinc (Mg-Zn) alloys reinforced with carbon nanofibres (CNF) through mechanical and morphological structures. Pure Mg, Zn, and CNF was prepared via powder metallurgy (PM) method. The samples were mechanically alloyed using planetary ball mill to create finer powder. Next, the samples were compacted using the Instron machine for 10 minutes at room temperature to produce a 10 mm diameter cylindrical platelet. Then, the specimens were heated with an argon gas flow for 4 hours at different sintering temperatures. The results showed that the optimum sintering temperature for Mg-Zn alloys reinforced with CNF was at 250℃ with elastic modulus and yield strength of 2729.886 MPa and 140.628 MPa, respectively. The findings of this study concluded that Mg-Zn alloys reinforced with CNF composites have great potential to be used as new biodegradable implants for medical applications in the future.

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