Microwave Equipment Considerations for High Temperature Studies in Ceramics

1988 ◽  
Vol 124 ◽  
Author(s):  
Martin Yonnone
Keyword(s):  
High Temperature ◽  
Microwave Heating ◽  
Microwave Field ◽  
Rapid Heating ◽  
Ceramic Materials ◽  
Microwave Energy ◽  
Ceramic Samples ◽  
Scientists And Engineers

The utilization of microwave energy as a source for the heating of ceramic materials is not a recent discovery. Notably, Von Hippel(1) and others including Tinga(2) investigated the microwave heating of ceramic materials in the 50's and 60's. Today, many microwave scientists and engineers are working on the complexities associated with the rapid heating exhibited by ceramic samples in the microwave field.

In—Line Measurement Of High Temperature Dielectric Constant In The Process Of Sintering

1996 ◽  
Vol 430 ◽  
Author(s):  
Zhou Jian ◽  
Cheng Jiping ◽  
Tang Yuling ◽  
Qiu Jinyu
Keyword(s):  
Dielectric Constant ◽  
High Temperature ◽  
Resonant Cavity ◽  
Ceramic Materials ◽  
Dielectric Constants ◽  
Experimental Results ◽  
Cavity Method ◽  
Experimental Basis ◽  
Ceramic Samples ◽  
Line Measurement

AbstractIn this paper, a resonant cavity method is developed and some experimental results for measuring dielectric constants of ceramic samples (e. g. Al2O3) under different sintering temperatures are reported. The experiments show that this method has higher precision and good prospects of in—line monitoring the high temperature dielectric constant in the process of raising the temperature of the samples. These results provide some scientific experimental basis for physical research of ceramic materials.

Wavelet analysis of ceramic surface images as a method for measuring the size of structural elements

2020 ◽  
pp. 50-54
Author(s):  
M. M. Filyak ◽  
A. G. Chetverikova ◽  
O. N. Kanygina ◽  
I. N. Anisina
Keyword(s):  
Wavelet Analysis ◽  
Structural Changes ◽  
Microwave Field ◽  
Ceramic Materials ◽  
Modern Method ◽  
Wavelet Spectrum ◽  
Ceramic Surface ◽  
Structural Elements ◽  
Ceramic Samples ◽  
Simple Geometry

The expediency of applying the wavelet analysis method to visualize and measure structural elements on the surface of ceramic samples is shown. The experimental results of image processing of the surface of samples made of kaolin clay using wavelet analysis are presented. Examples of applying the wavelet transform to the study of model images with simple geometry and precisely known sizes of structural elements of the “checkerboard” type are considered. A relation is proposed that relates the particle size to the scale parameter of the wavelet spectrum. A simple and modern method makes it possible to record and quantify the structural changes occurring in highly dispersed ceramic samples under the influence of a microwave field. It was found that on the surface of ceramic samples processed in a microwave field, the sizes of structural elements (particles) are reduced by an average of 20%; the surface itself becomes more uniform. This effect is extremely promising for the development of technology for producing finely dispersed ceramic materials.

Theory of Sublinear Power Dependence of Microwave Heating in Some Ceramic Materials

1992 ◽  
Vol 269 ◽  
Author(s):  
V. M. Kenkre ◽  
M. Kus ◽  
J. D. Katz
Keyword(s):  
Simple Model ◽  
Grain Boundary ◽  
Microwave Heating ◽  
Microwave Field ◽  
Ceramic Materials ◽  
Absorption Efficiency ◽  
Power Dependence ◽  
Spatial Confinement ◽  
Model Calculations ◽  
Combined Action

ABSTRACTA sublinear dependence of the microwave heating rate on the incident microwave power implying a saturation effect appears to have been observed recently. We present simple model calculations to address this observation on the basis of an idea of spatial confinement of the absorbing charges in grain boundary regions. Two natural lengths exist in this model: the spatial extent of the confining region, and the maximum distance an absorbing charge travels under the combined action of damping and of the oscillating microwave field. We suggest that a mismatch of these lengths results in the observed saturation, more generally, in the observed decrease in absorption efficiency.

scholarly journals The effect of conductivity on hotspots

1992 ◽  
Vol 33 (4) ◽  
pp. 403-413 ◽  
Author(s):  
N. F. Smyth
Keyword(s):  
High Temperature ◽  
Microwave Heating ◽  
Energy Absorption ◽  
Industrial Application ◽  
Hot Spots ◽  
Industrial Applications ◽  
Microwave Energy ◽  
Nonlinear Dependence ◽  
Theoretical Understanding

AbstractIn industrial applications of microwave heating, it has been observed that rather than the heating taking place uniformly, regions of high temperature, called hot-spots, tend to form. Depending on the industrial application, these can be either desirable or undesirable, and hence a theoretical understanding of the properties of the material that lead to hotspot formation is necessary. It has been shown in previous studies that hotspot formation is a product of the nonlinear dependence of microwave energy absorption by the material on temperature. It is shown in the present work that the conductivity of the material can have a significant effect on hotspot formation and can, if large enough, stop a hotspot from forming.

Applications of microwave energy in gas production and tar removal during biomass gasification

2020 ◽  
Vol 4 (12) ◽  
pp. 5927-5946
Author(s):  
Feiqiang Guo ◽  
Yichen Dong ◽  
Beile Tian ◽  
Shilin Du ◽  
Shuang Liang ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Rapid Heating ◽  
Biomass Gasification ◽  
Microwave Energy ◽  
Gas Production ◽  
Biomass Pyrolysis ◽  
Selective Heating ◽  
Tar Removal

Microwave heating has the potential to promote gas production and tar removal during biomass pyrolysis or gasification based on its advantageous characteristics such as rapid heating and selective heating.

Preparation of WC-TiC-Ni3Al-CaF2 functionally graded self-lubricating tool material by microwave sintering and its cutting performance

2020 ◽  
Vol 39 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Siwen Tang ◽  
Rui Wang ◽  
Pengfei Liu ◽  
Qiulin Niu ◽  
Guoqing Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Microwave Heating ◽  
Cutting Performance ◽  
Conventional Heating ◽  
Hard Alloys ◽  
Dry Cutting ◽  
Temperature Oxidation ◽  
Lubricating Material ◽  
Heating Technology

AbstractWith the concern of the environment, green dry cutting technology is getting more and more attention and self-lubricating tool technology plays an important role in dry cutting. Due to the demand for high temperature performance of tools during dry cutting process, cemented carbide with Ni3Al as the binder phase has received extensive attention due to its excellent high temperature strength and high temperature oxidation resistance. In this paper, WC-TiC-Ni3Al-CaF2 graded self-lubricating material and tools were prepared by microwave heating method, and its microstructure, mechanical properties and cutting performance were studied. Results show that gradient self-lubricating material can be quickly prepared by microwave heating technology, and the strength is equivalent to that of conventional heating technology. CaF2 not only plays a role in self-lubrication, but also refines the grain of the material. A reasonable gradient design can improve the mechanical properties of the material. When the gradient distribution exponent is n1 = 2, the material has high mechanical properties. Cutting experiments show that the WC-TiC-Ni3Al-CaF2 functional gradient self-lubricating tool has better cutting performance than the homogeneous WC-TiC-Ni3Al hard alloys.

Effects of microwave heating in nanostructured ceramic materials

2010 ◽  
Vol 49 (1-2) ◽  
pp. 31-41 ◽  
Author(s):  
Yu. V. Bykov ◽  
S. V. Egorov ◽  
A. G. Eremeev ◽  
V. V. Kholoptsev ◽  
I. V. Plotnikov ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Ceramic Materials ◽  
Nanostructured Ceramic

The use of microwave heating for the pyrolysis of coal via inorganic receptors of microwave energy

Fuel ◽  
1992 ◽  
Vol 71 (6) ◽  
pp. 716-717 ◽  
Author(s):  
Parisa Monsef-Mirzai ◽  
Mythili Ravindran ◽  
William R. McWhinnie ◽  
Paul Burchil
Keyword(s):  
Microwave Heating ◽  
Microwave Energy
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