Asian industry is leading the development and switch to high-temperature microwave sintering, replacing inefficient gas and electric furnaces with this newer "green" technology. "Switching to microwave furnaces cuts energy use up to 80% and reduces processing time by 90% while creating higher-quality end products with finer grain and increased density, strength and corrosion resistance," says Joseph Hines, chairman of Phoenix-based Spheric Technologies, Inc. Sintering involves pressing metal or ceramic powders into shapes and subjecting them to controlled high heat to produce a finished solid object. Together, processing of powder metals and ceramics is a growing $13 billion industry in the U.S. alone, according to industry sources.
"Widespread adoption of microwave processing throughout the materials industries in the U.S. is inevitable," says Professor Rustum Roy, Ph.D., Founding Director, Pennsylvania State University Materials Research Laboratory and Research Professor in Materials at Arizona State University. "Until now, a primary obstacle has been the unavailability of sophisticated high temperature microwave furnaces."
Distributed by Spheric Technologies, custom-manufactured SPHERIC/SYNO-THERM™ computer-controlled microwave furnaces are the first production-size high temperature units marketed in the U.S. Many sintering applications fall under a family of microwave technology use patents developed by the Penn State Microwave Processing and Engineering Center; Spheric Technologies is the exclusive supplier of sublicenses for those patents.
High-temperature microwave furnaces are inherently "green". Microwaves heat the object being sintered and not the atmosphere around it or the furnace walls. With a smaller physical footprint and a substantially smaller carbon footprint, microwave furnaces offer far lower operating and end product costs.
Examples of microwave sintering savings include:
- Japan's National Institute of Fusion Science reports reduction of ceramic sintering time from 8 hours to 2 hours, energy consumption reduction from 335 KWh to 63 KWh, and reduction of electricity cost from $14 per batch to $7 per batch.
- Britain's Loughborough University, in cooperation with the National Institute of Fusion Science, reduced large-part alumina sintering time from 3 days to 8 hours, and reduced energy consumption from 12MWh to 1.2MWh.
- Canada's Ontario Energy Agency projects that if the Province's ceramics industry converted to microwave, they would save 412 million KWh per year, or the equivalent of one 350 MW coal fired power plant.
- The Penn State Materials Research Center cut sintering cycle time for cemented carbides from 2.5 hours to 15 minutes.
- The Spheric Technologies Development Center, in controlled microwave production runs, reduced sintering cycle time for a customer's ceramic product from 2,400 minutes to 750 minutes.
- Japan has completed pilot development using microwave for steel production. The U. S. Department of Energy estimates that conversion of domestic steelmaking to microwave would save up to 14 million tons of coal burned for energy, reducing pollutant emissions by over 30 million tons of carbon monoxide and carbon dioxide annually.
"The fact that microwave use is growing in Japan, China, India and Europe foretells widespread adoption here," Hines notes. "Soaring energy prices in the U.S. will continue to drive domestic industries to reduced-energy-consuming technologies. Political, public and investor demand for greener industrial operations is already shifting corporate spending and retooling priorities. Further, significant advances in the production of high-value metal powders like titanium are dramatically lowering their cost, making microwave sintering of these materials an affordable and highly desirable production method."
Hines says industrial microwave systems will succeed just as kitchen microwaves have. "Twenty years ago, home microwave units were futuristic oddities; in a few short years they became indispensable appliances, owing to the same attributes available with SPHERIC/SYNO-THERM industrial microwave systems - faster heating, smaller footprint, lower energy use and superior end products. Spheric Technologies is uniquely positioned to capitalize on this substantial green marketing opportunity."