3
Materials Programs
The committee’s assessment focuses primarily on three programs: AIM (Advanced Industrial Materials Program), CFCC (Continuous Fiber Ceramic Composites Program), and the Industrial Power Generation Program (which was recently transferred to the DOE Office of Power Technologies). The Industrial Power Generation program has some areas of synergy with the other programs, especially intermetallics (AIM) and ceramics (CFCC). As carryovers from prior years, the AIM and CFCC programs are not yet fully integrated into the IOF market-pull strategy based on the industry technology road maps. However, OIT is working toward their full integration (NRC, 1999). Table 3-1 provides an overview of these three programs, including the status of technology development, demonstration, and commercialization for each. Materials development in the IOF industry programs are not evaluated in any detail in this report.
ADVANCED INDUSTRIALS MATERIALS PROGRAM
The mission of the AIM program is to develop and commercialize new and improved materials to increase productivity, improve product quality, and increase energy efficiency in major industries. In this program, DOE national laboratories, in cooperation with more than 100 companies, are working on a variety of material systems: metals, intermetallics, ceramics, polymers, and composites. Since the establishment of the IOF Program, AIM has redirected much of its research to involve and coordinate it with IOF programs, especially research related to the aluminum, chemicals, forest products, glass, metalcasting, refineries, and steel industries. Research on high-temperature materials, corrosion resistance, and wear resistance are the key needs of these industries. AIM interacts with industry by a variety of means, including cooperative research and development agreements (CRADAs), work-for-others agreements, user centers, and informal agreements (Sorrell, 1999).
TABLE 3-1 Overview of OIT Materials Programs (Note there is no continuity across each row)
PROGRAM |
TECHNOLOGY DEVELOPMENT PHASE |
DEMONSTRATION PHASE |
COMMERCIALIZATION PHASE |
ADVANCED INDUSTRIALS MATERIALS (AIM) |
Uniform-droplet process for monosized powder and near-net shape forming Participants: ORNL, Northeastern University, MIT, Industry Panel |
Microwave joining of silicon carbide ceramics Participants: ORNL, Argonne National Laboratory (ANL), FM Technology, Stone & Webster, INEX, Inc. |
Intermetallic alloys for the steel industry Participants: ORNL, Sandusky International, Bethlehem Steel, Alloy Engineering and Casting, United Defense, Caterpillar, Thermadyne, Timken, Ford Motor Company, Polymer, Alcon, FMC, Delphi |
|
Advanced intermetallic alloys Participants: ORNL, Alloy Engineering and Casting, Duralloy Technology, Inco Alloys, Ford Motor Company, Dow Chemical Company, Shenango, United Defense |
Zeolite membranes for p-xylene separations Participants: Sandia National Laboratories, British Petroleum, Amoco |
Evaluation of processing effects on fluidity of gray cast iron Participants: ORNL, Citation |
|
Improved materials for kraft recovery boilers Participants: ORNL, a consortium of 18 pulp and paper companies |
Molybdenum disilicides for industrial applications Participants: Los Alamos National Laboratory, Shuller International, Inc. |
|
|
Membrane systems for light gases Participants: Los Alamos National Laboratory, Amoco |
Electrochemical reactor for chloro-alkali process Participants: Los Alamos National Laboratory CRADA (being finalized) |
CVD for low-emissivity glass coatings Participants: Sandia National Laboratories, Pilkington, Libbey and Owens, Ford Motor Company |
|
Composites by reactive metal infiltration Participants: Sandia National Laboratories |
Thermal conducitvity of ceramic coatings for lost foam casting Participants: ORNL, University of Alabama |
Improved refractories for the glass industry Participants: ORNL, a consortium of 34 glass manufacturers |
|
Chemically reactive thin films Participants: Sandia National Laboratories |
Advanced materials and processes (thermal cycling wear and corrosive environments) Participants: ORNL, A. Finkl and Sons, Inco Alloys, QC Forging, Necter Fab., Alcoa, FMC, PPG, Siebe, Norton |
Composition optimization, weldability and properties of thin-wall components cast by countergravity casting Participants: ORNL, Alloy Engineering and Casting, Caterpillar, General Motors Powertrain |
|
Conducting polymers Participants: Los Alamos National Laboratory |
|
Refining pipe hangers Participants: ORNL, Engineered Composites |
|
Molten salt membranes for separation of hydrogen and carbon monoxide Participants: Los Alamos National Laboratory |
Radiant barrier screens Participants: ORNL, AlliedSignal Composites, Alzeta Vision Glass |
Heat-treating furnace fan Participants: ORNL, AlliedSignal, General Electric, Engineered Composites, Solar Turbines |
|
Plasma immersion hardening Participants: Los Alamos National Laboratory |
Infrared burners Participants: ORNL, McDermott Technologies, Institute of Paper Science and Technology, Auburn University, Georgia Institute of Technology |
|
CONTINUOUS FIBER CERAMIC COMPOSITES (CFCC ) |
Materials and processes - direct metal oxidation (AlliedSignal Composites) - chemical vapor infiltration (AlliedSignal Composites) - melt infiltration (General Electric) - polymer impregnation and pyrolysis (Dow) - sol-gel processing (McDermott Technologies) - reaction bonding (Textron Speciality Materials) - cold isostatic pressing and hot isostatic pressing (AlliedSignal) |
Supporting technologies a - microstuctural characterization (ORNL) - standards and codes (University of Washington) - mechanical test methods (ORNL) - nondestructive characterization (ANL) - interfaces and seal coatings (ORNL) - mullite coatings development (Boston University) - environmental barrier coatings (ORNL) - oxide coatings and materials (Northwestern University) - time-dependent behavior (ORNL) - environmental effects in ceramic composites (ORNL) |
Applications development - heat-treating furnace fan (Engineered Composites) - radiant burner screens (AlliedSignal, Alzeta, Vision Glass) - infrared burners (Institute of Paper Science and Technology, Auburn University, and Georgia Institute of Technology) - immersion tubes (Textron Systems) - hot-gas filters (McDermott Technologies, Siemens, Southern Companies Services) - refinery pipe hangers (Engineered Composites) |
INDUSTRIAL POWER GENERATION (Advanced Turbine Systems) |
Advanced materials for gas turbines Participants: ORNL, Pratt and Whitney, Westinghouse, ANL, National Institute of Standards and Technology |
|
Ceramics for gas turbines Participants: ORNL, Solar Turbines, AlliedSignal, B.F. Goodrich |
a |
Supports both CFCC and Industrial Power Generation Programs |
AIM has successfully developed an intermetallic alloy (Ni3Al )for the steel industry (NRC, 1997). In a presentation to the committee, a representative of ORNL noted that Ni3Al has excellent high-temperature strength and corrosion resistance (Angelini, 1999). Scientists at ORNL are also working on boron additions to this alloy to make it much less brittle. One of the most promising applications for this material is for rolls in steel heat-treating furnaces. In collaboration with Sandusky International and Bethlehem Steel, about 20 rolls of this material were tested and used without signs of blistering. The material is also being tested for radiant burner tubes and carburizing fixtures for heat-treating furnaces. In this long term R&D program, the material was developed from laboratory scale in 1980 to its current application. The new rollers are expected to save 32 trillion BTU by the year 2010 (Angelini, 1999).
AIM has also successfully developed materials for use in kraft recovery boilers, which are used in the paper and pulp industry to concentrate waste fluids (Adams, 1997). Historically, cracks in the boiler tubes caused one or two explosions a year. DOE organized a work team of 27 scientists and engineers (18 from the paper and pulp industry, three from research laboratories, and six from tube suppliers) to solve this problem. An examination by the team of the boiler tubes in operation revealed that, because of corrosion, transient hot spots developed in the tubes, which significantly increased stress in the vicinity of the hot spot. Eventually, stress corrosion cracking occurred resulting in the rupture of the tubes. The tubes were 304 stainless-steel clad carbon-steel tubes. The problem was solved by changing the cladding from 304 stainless steel to alloy 825 or a modified alloy 625. This example shows how interaction with industry can lead directly to the improvement of an industrial process.
Other successful projects by AIM include: refractories for glass production; composite zeolite/amorphous membranes for hydrocarbon separation; countergravity casting; uniform-droplet processing; membranes for gas separation; and low-e coatings for window glass. All of these projects are characterized by strong interactions between national laboratories, universities, and industrial recipients of the material improvements. In fact, collaborative interactions with industry have been the strength of the AIM program. As more OIT programs are integrated into the IOF market-pull strategy, the committee anticipates that there will be many more successful projects.
CONTINUOUS FIBER CERAMIC COMPOSITES PROGRAM
The CFCC program was initiated in 1992 to produce lightweight, strong, corrosion-resistant materials capable of performing in high-temperature environments. CFCC is carried out collaboratively by industry, national laboratories, and universities. The ultimate goal of the program is to improve processing methods
to produce reliable, cost-effective, ceramic materials that can be commercialized by industry. In contrast to the AIM program, the CFCC program is focused on a type of material rather than an industrial problem. Nevertheless, CFCC-developed materials are serious contenders (technologically) in some commercial markets, including radiant burners, immersion tubes, hot-gas filters, furnace fan blades, combuster liners for gas turbines, and other applications. If fiber costs can be reduced, some of these products may be commercialized in the next few years (M. Smith, 1999).
The most widely publicized application of CFCC materials is combuster liners in gas turbines that could increase engine efficiency by reducing the required amount of cooling air. The simultaneous reduction in burning temperature for a given turbine inlet temperature could also decrease emissions of nitrogen oxides and carbon dioxide. With composite shrouds, large gas turbines would require no cooling and hence would have similar advantages. Because silicon carbide composites have sufficient strength and excellent strain tolerance, they avoid failure by thermal shock. Before silicon carbide composite combuster liners can be used commercially, however, their susceptibility to steam corrosion in the hot gas stream of the combuster will have to be overcome. Oxide coats of various compositions are currently being tried to obviate this problem. Costs will also have to be reduced before widespread industrial uses can be considered (Craig, 1999).
INDUSTRIAL POWER GENERATION PROGRAM
This goal of this program is to design and produce cleaner, more energy-efficient methods of generating electric power. A major part of the program is focused on improving gas turbines. R&D projects are focused on coating and process development, improved single-crystal airfoil manufacturing, materials characterization, ceramics development, and catalytic combuster materials. Most of these are collaborative projects involving industry, universities, and the national laboratories (Hoffman, 1999).
One of the longest lived projects has been on the use of ceramics for hot-section components in gas turbines. Solar Turbines, Incorporated, which is studying advanced ceramics to improve the performance of gas turbines, has retrofitted the Centaur 50S engine with a CFCC silicon carbide combuster, a silicon nitride nozzle, and silicon nitride blades (Hoffman, 1999; Karnitz et al., 1999). In demonstrations, the engine ran at full power for extended periods (up to 1,000 hours) with higher engine efficiency, higher power output, and lower nitrogen oxide and carbon monoxide emissions. The major problem was the oxidation of the silicon nitride and silicon carbide in the turbine environment. Research is now under way to develop protective coatings to extend the lifetime of the ceramic components. Until this problem is solved, nonoxide ceramics cannot be used under the anticipated corrosive, high-temperature conditions of gas turbines.
A more traditional way of achieving higher turbine inlet temperatures is to coat air-cooled, single-crystal alloy blades with thermal-barrier coatings. Several turbine engine companies have programs in this area (Karnitz et al., 1999). The national laboratories are working with Pratt & Whitney Aircraft Company and Siemens Westinghouse Power Corporation to develop and test thermal-barrier coatings for use on critical hot-section components of gas turbines. This is a relatively new project, and no final results were available from either company. In 1999, they were in the materials selection and test development stage.