Comparison of hot-pressing, rate-controlled sintering, and microwave sintering of magnesium aluminate for optical applications

1999 ◽  
Author(s):  
Gary A. Gilde ◽  
Parimal J. Patel ◽  
Mark Patterson
Keyword(s):  
Hot Pressing ◽  
Microwave Sintering ◽  
Magnesium Aluminate ◽  
Pressing Rate ◽  
Rate Controlled ◽  
Optical Applications

Terahertz Dielectric Properties of Polycrystalline MgAl2O4 Spinel Obtained by Microwave Sintering and Hot Pressing

2019 ◽  
Vol 40 (4) ◽  
pp. 447-455
Author(s):  
S. V. Egorov ◽  
A. A. Sorokin ◽  
I. E. Ilyakov ◽  
B. V. Shishkin ◽  
E. A. Serov ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Hot Pressing ◽  
Microwave Sintering ◽  
Mgal2o4 Spinel

Effect of HIP on the Properties and Microstructure of Transparent Polycrystalline Spinel

2007 ◽  
Vol 336-338 ◽  
pp. 1200-1202 ◽  
Author(s):  
Mu Yun Lei ◽  
Cun Xin Huang ◽  
Jia Lin Sun
Keyword(s):  
Grain Size ◽  
Optical Properties ◽  
Hot Pressing ◽  
Hot Isostatic Pressing ◽  
Magnesium Aluminate ◽  
Magnesium Aluminate Spinel ◽  
Sintering Aid ◽  
Average Transmittance ◽  
Before And After ◽  
Spinel Powder

In this paper, transparent polycrystalline magnesium aluminate spinel was fabricated by hot pressing ultra fine high purity spinel powder using LiF as the sintering aid in vacuum, then hot isostatic pressing (HIPing) the sintered body to improve the optical properties of the sample. The transmittance and the strength of the samples before and after HIPing were measured; morphologies of the fracture surface of the samples before and after HIPing were observed. Following hot pressing, the grain size of the sample is small; the transmission values are low and may varied at different sites in the same sample. After HIPing, the strength of the sample decreased, the grain size increased obviously, and the transmittance and the uniformity of transmittance increased significantly. The panel of transparent spinel up to 200 mm in diameter and 8 mm thick was fabricated by this method; the average transmittance of the spinel is above 80% in the range between 2 μm and 5 μm .

scholarly journals Microwave Sintering of Boron Carbide

1988 ◽  
Vol 124 ◽  
Author(s):  
J. D. Katz ◽  
R. D. Blake ◽  
J. J. Petrovic ◽  
H. Sheinberg
Keyword(s):  
Grain Size ◽  
Boron Carbide ◽  
Microwave Radiation ◽  
Hot Pressing ◽  
Microwave Sintering ◽  
Theoretical Density ◽  
Energy Usage ◽  
Average Grain Size

ABSTRACTBoron carbide has been sintered to 95% of theoretical density in less than 12 minutes without the use of sintering aides by heating to 2000°C with 2.45 GHz microwave radiation. An average grain size of about 20 μm resulted. Twins and microcracking were present in the microstructure. Energy usage for microwave sintering was found to be 18% less than for inductive hot-pressing.

Microwave Sintering of ZrO2 Fiber-Reinforced Hydroxyapatite Matrix Composites

2012 ◽  
Vol 14 ◽  
pp. 93-106 ◽  
Author(s):  
N. Ehsani ◽  
A.J. Ruys ◽  
C.C. Sorrell
Keyword(s):  
Microwave Heating ◽  
Hot Pressing ◽  
Microwave Sintering ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Conventional Sintering ◽  
Zirconia Fibre ◽  
Microwave Hybrid Heating ◽  
Suitable Area ◽  
Future Work

PSZ (ZrO2Fiber)-reinforced HAp was sintered using conventional and microwave hybrid heating. Microwave heating cycles were ~50 times faster than conventional sintering cycles and enabled the use of reduced densification temperatures and soak times by as much as ~100°C and 55 min, respectively. However, although there was a significant improvement in densification levels attainable before decomposition, the improvements were insufficient to produce near-fully or fully dense samples. However, the promising gains made suggest that microwave hot pressing would be a suitable area for future work. Keywords: Hydroxyapatite, microwave sintering, fibre-reinforced ceramics, bioceramics, zirconia fibre

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