New, super-tough ceramics with high-tech promise
Cambridge — Advanced ceramics may sound like fancy pottery. But it's actually a promising field of high technology that the Massachusetts Institute of Technology (MIT) is spending $1.5 million to explore.
Stashed away in an air-conditioned laboratory of lasers, gauges, tubes, and jars filled with colored powders, scientists at MIT's Energy and Materials Processing Laboratories have begun development of extremely hard, durable, heat-resistant, lightweight ceramic materials. These new substances have properties so diverse that they may soon be replacing the metal parts in automobile engines, the diamonds in industrial cutting tools, or the plastics in computer component packaging.
While older-style ceramics are still used as insulators in spark plugs, recent experiments, primarily in Japan, have produced hard but, unfortunately, brittle new materials. The problem for researchers has been to find a means of improving the quality and consistency of high-tech ceramics.
MIT has developed a ''completely new strategy for working with these materials,'' says John S. Haggerty, program manager at MIT's Energy Laboratory.
The MIT process involves blowing a combination of gases across the beam of a carbon-dioxide laser: The laser heats the gases, a chemical reaction begins, and nuclei form and grow. This creates millions of tiny particles of uniform size, which are eventually packed into powders, then baked to make ceramics. The MIT researchers are working with silicon carbide and silicon nitride powders.
''Using a powder with uniform particle size, you can control the material better,'' Dr. Haggerty says. ''In the past, the presence of defects precluded their use in any area open to stress.
''A tiny piece of ceramic kicking around inside an engine can take it out,'' he adds. ''And there is no way that an auto manufacturer can take such a risk or tolerate such a high incidence of failure.''
A parallel program in engine research gearing up for the fall at MIT's Sloan Laboratory for Automotive and Aircraft Engines will provide what Haggerty calls a ''nice merging of interests'' and a ''friendly test bed for ceramic parts.''
The United States has been experimenting with ceramic engines for several years. Ceramic automobile engines require no cooling system, are 30 to 40 percent lighter than metal engines, can burn diesel, light oil, or gasoline, and are 30 to 50 percent more fuel efficient.
Cummins Engine Company in Columbus, Ind., has recently developed an uncooled diesel engine with ceramic-lined combustion chambers for the US Army.
But Haggerty insists that ''Japan is where the action is.''
In 1981, Japan's Ministry of International Trade and Industry allocated special funding for research and development of high-performance ceramics and six other materials.
Last month, Ishikawajima-Harima Heavy Industries Company of Japan announced it had commercially developed the first automobile turbocharger with key components, such as the turbine blades and turbine axle, made in one piece out of ceramic silicon nitride.
In a recent Ceramic Bulletin, Haggerty's associates, George B. Kenney and H. Kent Bowen, estimate the current worldwide market for fine ceramics at $4.25 billion. ''Roughly half of this demand is currently being met by Japanese companies, where sales of fine ceramics exceeded $2 billion in 1980,'' the authors say.
Currently ''electronics applications account for approximately 88 percent and 70 percent of the total market value of Japanese and world production of fine ceramics respectively,'' they continue. However, this market is ''dwarfed by the potential size and impact of fine ceramics in heat-resistant applications'' such as engines.
Haggerty points out the potential of ceramics for in magnetic, optical, chemical, thermal, mechanical, biological, and nuclear applications as well.
Are American firms interested in MIT's new process and its potential?
''We first attempted to sell the idea domestically to 100 companies - automobile manufacturers, computer companies, everyone,'' Haggerty says. ''The general response was basically: 'Don't call us, we'll call you.'
''But the Japanese were right on it. Our scale-up and processing research will be sponsored by seven companies. At the moment, five of those are Japanese.''