Continuous Processing of Sheet-Like Materials by Microwave Energy

1996 ◽  
Vol 430 ◽  
Author(s):  
David A. Lewis ◽  
Stanley J. Whitehair ◽  
Alfred Viehbeck ◽  
Jane M. Shaw
Keyword(s):  
Microwave Processing ◽  
Microwave Energy ◽  
Circuit Board ◽  
Process Window ◽  
Glass Cloth ◽  
Continuous Processing ◽  
Microwave Applicator ◽  
Initial Results

AbstractInitial results for the continuous microwave processing of wide webs using a new microwave applicator are presented. The results show that acceptable uniformity can be obtained using this system and that with the appropriate controls, a very tight process window can be maintained to produce preimpregnated glass cloth (prepreg) for use in circuit board manufacture.

Microwave Processing at the University of Florida

1994 ◽  
Vol 347 ◽  
Author(s):  
D. E. Clark ◽  
D. C. Folz ◽  
R. L. Schulz ◽  
Z. Fathi ◽  
A. D. Cozzi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Microwave Processing ◽  
Microwave Energy ◽  
Development Work ◽  
University Of Florida ◽  
Waste Remediation ◽  
Manufacturing Operations ◽  
Processing Techniques ◽  
The University

ABSTRACTMicrowave energy for processing materials is emerging as a vital manufacturing technology for the nineties and beyond. Research to date has shown significant advantages in several areas, including drying and sintering, joining, surface modification and waste remediation. Increased processing rates, improved physical and mechanical properties and, in some cases, reduced hazardous emissions have sparked the interest of many manufacturers in the ability to integrate microwave processing techniques into existing and future manufacturing operations. This presentation will provide an overview of the microwave processing research and development work in progress at the University of Florida.

scholarly journals Artifacts from Rapid Microwave Processing of Trematode Tissues (Ascocotyle pachycystisandleighi)

2004 ◽  
Vol 12 (5) ◽  
pp. 32-35
Author(s):  
Mark H. Armitage
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Biological Tissues ◽  
Microwave Processing ◽  
Microwave Energy ◽  
Significant Interest ◽  
Positive Results ◽  
Tissue Ultrastructure

The use of microwave energy to assist in the processing of biological tissues for microscopy has generated significant interest in recent years. Microwave (MW) processing has been used to prepare tissues for light microscopy (Carranzaet al.1990 [using parasite tissues]; van Dorpet al.1995; Daviset al.1997; Izumiet al2000; and Rohret al.2001), as well as for electron microscopy (Kasaet al.1982; Hopwoodet al.1984; Leonget al.1985; Kanget al,1991 [using parasite tissues]; Heumann 1992; Wagenaaret al.1993; Login and Dvorak 1993; Giberson and Demaree 1995; Madden and Miriam 1997; Gibersonet al.1997; Morinet al.1997; Petrali and Mills 1999; Massa and Arana-Chavez 2000; Hernandez and Guillen 2000 [using parasite tissues]; Demaree 2001; Giberson 2001).Most reports, particularly those published by manufacturers of microwave ovens, have shown positive results regarding tissue ultrastructure, however discussion continues on possible mechanisms of preservation by the use of MW technology.

Microwave Processing of Ceramics - An Overview

1992 ◽  
Vol 269 ◽  
Author(s):  
Willard H. Sutton
Keyword(s):  
State Of The Art ◽  
Microwave Processing ◽  
Microwave Energy ◽  
Early Developmental Stage ◽  
Future Directions ◽  
New Developments ◽  
The Past ◽  
Current State ◽  
Potential Benefits ◽  
Early Developmental

ABSTRACTDuring the past decade, many exploratory studies and experiments have been performed on the microwave heating and processing of ceramics and composite materials. Much of this effort was stimulated by the unique and potential benefits that microwave energy can provide over conventional processing methods. While microwave processing of ceramics is still in an early developmental stage, there are many areas yet to be explored, challenges to be met, and economic and commercial payoffs to be substantiated.Since the first MRS International Symposium on Microwave Processing in 1988, interest in this field has grown and many new developments have occurred. The purpose of this paper is to highlight some of the recent advances, to discuss the current state-of-the-art, and to suggest some future directions.

Joining Ceramics Using Microwave Energy

1993 ◽  
Vol 314 ◽  
Author(s):  
Iftikhar Ahmad ◽  
Richard Silberglitf
Keyword(s):  
Silicon Carbide ◽  
Silicon Nitride ◽  
Processing Time ◽  
Single Mode ◽  
Microwave Energy ◽  
Internal Heating ◽  
The Past ◽  
Complex Shapes ◽  
Microwave Applicator ◽  
Sintered Silicon

AbstractIn the past several years there has been an explosive growth in the use of microwave energy for the processing of a host of materials. Microwave energy provides rapid internal heating which results in an overall reduction in the processing time. The important features of microwave processing are described, as well as several applications.Microwave energy has been used by a few groups for the joining of alumina, mullite, silicon nitride and silicon carbide. The work performed by these groups will be reviewed. Typically, a single mode microwave applicator has been used to join ceramics at temperatures ranging between 1250°C - 1800°C. Microwave joining of ceramics was achieved in a matter of minutes, in contrast to hours reported by conventional methods. The strength of the joints was equal to or greater than the as-received materials. Joining of specimens of sintered silicon carbide (Hexoloy ™ ) using interlayers, and direct joining of reaction bonded silicon carbide (RBSC) to itself and Hexoloy™ has been accomplished recently. Both single mode and multimode microwave applicators were used and larger specimens of RBSC having complex shapes were joined using hybrid heating. The paper describes microwave joining apparatus, techniques and results.

Improved Grindability of Iron Ores using Microwave Energy

1988 ◽  
Vol 124 ◽  
Author(s):  
J. W. Walkiewicz ◽  
S. L. McGill ◽  
L. A. Moyer
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Microwave Heating ◽  
Temperature Control ◽  
Microwave Energy ◽  
Iron Ores ◽  
Work Index ◽  
Continuous Feed ◽  
Microwave Applicator ◽  
Scanning Electron

ABSTRACTThe Bureau of Mines, U.S. Department of the Interior, has conducted studies to utilize rapid microwave heating to stress fracture ore samples. Iron ores containing hematite, magnetite, and goethite were subjected to microwave energy in batch operations at 3 kW and heated to average temperatures between 840° and 940° C. Scanning electron microscope (SEM) photomicrographs verified fracturing along grain boundaries and throughout the gangue matrix. Standard Bond grindability tests showed that microwave heating reduced the work index of iron ores by 9.9 to 23.7 pct. Preliminary studies using a continuous feed belt in a microwave applicator indicated that samples heat more uniformly and with better temperature control than in batch operations.

scholarly journals Formation mechanism analysis and experimental investigation of single-step printing customized circuits by liquid-metal direct writing

2021 ◽  
Vol 12 (1) ◽  
pp. 143-154
Author(s):  
Yan Pu Chao ◽  
Hao Yi ◽  
Hui Cen ◽  
Yao Hui Li
Keyword(s):  
Liquid Metal ◽  
Printed Circuit Board ◽  
High Surface ◽  
Single Step ◽  
Green Technology ◽  
Circuit Board ◽  
Process Window ◽  
Mechanism Analysis ◽  
Direct Writing ◽  
Liquid Metal Ink

Abstract. Liquid-metal direct writing is a cost-effective and green technology, which is very promising for the customized fabrication of flexible circuits and functional devices. However, owing to the high surface tension of metal ink, the printed circuits are prone to intermittent outflow, large forming size error, and unstable forming. The smooth flowing and conveying of liquid-metal ink are still huge challenges that need significant attention. Herein, the force mechanism of liquid-metal ink transported by ball rotation and translation of the printing head was analysed, and the wetting characteristics of liquid metal on the surface of different substrates and its influence on forming morphology were investigated. The stable output printing of gallium indium alloy (GaIn24.5) liquid metal was realized. The changing characteristics of the shape and size of the liquid-metal circuits formed under different printing speeds and writing pressures were experimentally studied. The effective process window for obtaining the best circuit quality was established. Based on this, a flexible printed circuit board and functional electronic pattern were successfully printed under the writing pressure W=1 N and printing speed F800 mm min−1. The printed lines of GaIn24.5 exhibited a smooth surface, uniform width, small size error, and ability to connect electronic components and conduct electricity. This research proposes a new technical approach for customized printing of personalized electronic circuits and has important application prospects in the future.

Size-effect in microwave processing of engineering materials - A review

2020 ◽  
Vol 14 (2) ◽  
pp. 6770-6788 ◽  
Author(s):  
Dhirendra N. Gamit ◽  
Mahesh K. Chudasama
Keyword(s):  
Size Effect ◽  
Food Processing ◽  
Review Paper ◽  
Microwave Processing ◽  
Microwave Energy ◽  
Particle Sizes ◽  
Effective Surface ◽  
Chemical Manufacturing ◽  
Microwave Materials ◽  
Engineering Materials

The size of material units is especially critical in manufacturing processes where thermal energy interacts with the material. The microwave energy is widely used to process the materials in industries such as food processing, chemical, manufacturing etc. due to its unique heating characteristics. In microwave processing, energy is generated and absorbed inside the material during irradiation. The energy absorbed per unit volume of the material depends upon its size. The smaller size candidate materials have more effective surface area to absorb microwave energy than the bulk ones and usually yield lesser defects. This review paper summarizes the fundamentals of size-effect, microwave–materials interaction and input/output parameters in microwave material processing. Further, size-effect in microwave processing of different type of engineering materials (metal based, ceramic based and polymer based) have been discussed in terms of energy absorption and improvement in product attributes. The challenges in microwave processing of metal based materials have been identified and opportunities have been outlined in order to improve the properties vis-à-vis particle sizes during microwave processing.

On microstructural and mechanical properties of 21-4-N nitronic steel joint developed using microwave energy

2021 ◽  
pp. 251659842110334
Author(s):  
Shivani Bhandari ◽  
Shivani Gupta ◽  
Radha Raman Mishra ◽  
Apurbba Kumar Sharma ◽  
Navneet Arora
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Base Metal ◽  
Nickel Powder ◽  
Weld Zone ◽  
Microwave Energy ◽  
Complete Fusion ◽  
Carbide Phases ◽  
Microwave Applicator ◽  
Heating Mode

In the current experimental work, an effort has been made to explore the feasibility of fusion joints of 21-4-N nitronic steel employing microwave heating. These fusion joints were developed inside a domestic microwave applicator operating at 900 W. Microwave energy was used to fabricate the joints in hybrid heating mode by converting electromagnetic energy into heat at 2.45 GHz. Charcoal and SiC plates were used as susceptor and separator, respectively, and nickel powder was used as the interface material. The developed joints were characterized for their microstructural and mechanical properties. The microstructures indicate a complete fusion of nickel interfacing powder with the faying surfaces. XRD results show the formation of metallic nitrides and carbide phases (Cr2N, Fe3N, and Fe2C) and the FeNi phase at the weld zone. Furthermore, the observed average tensile strength of the fusion joints was approximately 61% of base metal. The reduction in the stress and elongation compared to the base metal were 38.67% and 12.68%, respectively. The average microhardness of the microwave joints was monitored as 407 ± 69.27 HV. The results indicate the feasibility of fusion joints of nitronic steel using microwave energy.

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