Low-Temperature Sintering of ZnO–TiO2 Ceramics

Author(s):  
Zhengwei Nie ◽  
Yuyi Lin ◽  
Feixue Wang

Vanadium pentoxide (V2O5) was chosen as a sintering aid to lower the sintering temperature of the ZnO–TiO2 system. The effect of V2O5 on the sintering behavior and material properties of ZnO–TiO2 ceramics and cermets made of ZnO–TiO2 ceramics and copper (Cu) was investigated as a function of V2O5 percentage and sintering temperature. Densities and hardness of the specimens were improved with an increase of V2O5 up to 2 wt. %. The sintering temperature of the specimens can be reduced to below 1000 °C. The properties of ZnO–TiO2 ceramics and cermets made from ZnO–TiO2 ceramics and Cu with V2O5 are strongly dependent on the sintering temperature. The density of ZnO–TiO2 ceramics and cermets was increased up to 95%, 90% of theoretical density at 900–920 °C, 960–1000 °C, respectively, for 4 hrs.

2010 ◽  
Vol 663-665 ◽  
pp. 1028-1031
Author(s):  
Yue Ming Li ◽  
Hua Zhang ◽  
Zhu Mei Wang ◽  
Yan Hong ◽  
Zong Yang Shen

The sintering behavior and microwave dielectric properties of the (Ca0.9375Sr0.0625)0.25(Li0.5Sm0.5)0.75TiO3 (CSLST) ceramics doped with different amounts of Li2O-B2O3-SiO2-CaO-Al2O3 (LBSCA) glass were investigated. The sintering temperature of the CSLST ceramics can be effectively reduced over 200oC due to the addition of LBSCA glass. For the 5 wt% LBSCA-doped CSLST ceramics, which are sintered at only 1000 oC for 5 h, show optimum microwave dielectric properties as follows: εr=84.74, Qf=2446 GHz and τf=-12.48 ppm/oC.


2009 ◽  
Vol 66 ◽  
pp. 104-107 ◽  
Author(s):  
Ying Dai ◽  
Yao Sun ◽  
Wen Chen

Willemite ceramics (Zn2SiO4) possess excellent millimeter-wave dielectric properties, but it also has a high sintering temperature above 1300°C by traditional solid-state reaction and relatively large negative τf value. Zn2SiO4 nanoparticles synthesized by Sol–Gel method were used to improve the sintering and dielectric properties of the Zn2SiO4 ceramics. Using the nanoparticles, Zn2SiO4 ceramics can be sintered at a low temperature, 1150°C and exhibited improved microwave dielectric properties of εr =6.62, Q × f=24500 GHz, τf =-59ppm/°C. By adding TiO2 with high positive τf value (+450 ppm/°C) and CuO as sintering aid, near zero τf value and low sintering temperature can be achieved. With 11wt% of TiO2 and 5 wt% of CuO, an εr value of 9.3, a Q × f value of 12200GHz and a τf value of -11 ppm/°C were obtained at 1000°C, confirming the promising potential of the CuO-added TiO2-Zn2SiO4 ceramics as candidate materials for low–temperature cofired ceramic (LTCC) devices.


2021 ◽  
Vol 16 (3) ◽  
pp. 517-524
Author(s):  
Poppy Puspitasari ◽  
A. Muhammad ◽  
A. A. Permanasari ◽  
T. Pasang ◽  
S. M. S. N. S. Zahari ◽  
...  

Samarium cobalt is known as super high density magnetic material with large magnetic anisotropy energy. Samarium–cobalt exhibits manipulative magnetic properties as a rare-earth material which has different properties in a low sintering temperature. It is therefore of paramount importance to investigate samarium cobalt (Sm2Co17) magnetic properties in the low temperature sintering condition. Sm2Co17, which is utilized in this research, is synthesized via the sol–gel process at sintering temperatures of 400, 500, and 600 °C. Subsequently, the crystallites indicate the formation of a single-phase Sm2Co17 on all the samples in all temperature variations. Moreover, the peaks in the X-ray diffraction analysis of crystallite sizes calculated using the Scherrer equation are 17.730, 15.197, and 13.296 nm at 400, 500, and 600 °C. Through scanning electron microscopy, the particles are found to be relatively large and agglomerated, with average sizes of 143.65, 168.78, and 237.26 nm. The functional groups are also analyzed via Fourier-transform infrared spectroscopy, which results in the appearance of several bonds in the samples, for example, alkyl halides, alkanes, and esters with aromatic functional groups on the fingerprint area and alkynes, alkyl halides, and alcohol functional groups at a wavelength of above 1500 cm. The test results of the magnetic properties using vibrating-sample magnetometer (VSM) revealed high coercivity and retentivity in the samples sintered at 400 °C. However, the highest saturation occurs in the samples sintered at 600 ℃. At a low sintering temperature (below 1000 °C), samarium cobalt shows as the soft magnetic material. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 


2010 ◽  
Vol 25 (3) ◽  
pp. 471-475 ◽  
Author(s):  
Sea-Hoon Lee ◽  
Byung-Nam Kim ◽  
Hidehiko Tanaka

Al8B4C7 was used as a sintering additive for the densification of nano-SiC powder. The average grain size was approximately 70 nm after sintering SiC-12.5wt% Al8B4C7 at 1550 °C. The densification rate strongly depended on the sintering temperature and the applied pressure. The rearrangement of SiC particles occurred at the initial shrinkage, while viscous flow and liquid phase sintering became important at the middle and final stage of densification.


2012 ◽  
Vol 512-515 ◽  
pp. 1226-1230
Author(s):  
Qun Zeng ◽  
Yong Heng Zhou

The structure, microwave dielectric properties and low-temperature sintering of a new Li2O-Nb2O5-TiO2 system ceramic with the Li2O: Nb2O5: TiO2 mole ratio of 1.52: 0.36: 1.34 have been investigated in this study. The 1.52Li2O-0.36Nb2O5-1.34TiO2 (LNT) ceramic is composed of two phases, the “M-Phase” and Li2TiO3 solid solution (Li2TiO3ss) phase. This new microwave dielectric ceramic has low intrinsic sintering temperature ( ~ 1100 oC ) and good microwave dielectric properties of middle permittivity (εr ~38.6), high Q×f value up to 7712 GHz, and near zero τf value (~ 4.64 ppm/oC). In addition, the sintering temperature of the LNT ceramics could be lowered down effectively from 1100 oC to 900 oC by adding 1 wt.% B2O3. Good microwave dielectric properties of εr = 42.5, Q*f =6819 GHz and τf = 2.7 ppm/oC could be obtained at 900 oC, which indicate the ceramics would be promising candidates for low-temperature co-fired ceramics (LTCC) applications.


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