 Cummins engine |
The goal of advanced materials research is to develop improved or advanced materials for the next generation of clean, efficient, reliable, and affordable distributed generation technologies. Research activities address the highest-priority materials needs for industrial gas turbines, microturbines, and reciprocating engines identified by panels of industrial experts.
Understanding the life-limiting characteristics of advanced materials, predicting component life, and detecting processing or service degradation are key components of developing reliable, advanced energy sources. The following projects address these needs:
- Reliability Evaluation of Microturbine Components — Dr. H.T. Lin
- Long-Term Testing in Water Vapor Environments — Dr. Matt Ferber
- Reliability Analysis of Microturbine Components — Dr. Stephen Duffy
- NDE Technology Development — Dr. Bill Ellingson.
The development and performance of advanced gas turbine engines is strongly dependent on the capabilities of the materials used to withstand increasing stress and temperature for long periods of time. Further, the ever-improving performance of gas turbines is dependent on the development of advanced materials. As operating temperatures and durability requirements are pushed, an understanding of how the materials will perform is critical to developmental progress. Ceramics and ceramic composite materials are of interest to the gas turbine development community because they offer potential approaches to increases in engine performance. Consequently, these materials are characterized to understand their capabilities and limitations and to explore methods to overcome the limitations. Projects include:
- Oxidation/Corrosion Characterization of Monolithic Silicon Nitride and Environmental Barrier Coatings — Dr. Karren More
- Mechanical Characterization of Monolithic Silicon Nitride — Dr. Roger Wills
- Hot Section Components in Advanced Microturbines — Dr. Bjoern Schenk
- Microstructural Characterization of Continuous Fiber Ceramic Composites and Protective Coatings — Dr. Karren More
- High-Temperature Environmental Effects on Ceramic Materials — Dr. Peter F. Tortorelli
- High-Speed Burner Rig Development — Dr. Bjoern Schenk.
Silicon-based ceramics including silicon nitride and silicon carbide have long been leading contenders for structural use in gas turbine engines because of their high-temperature strength, creep resistance, and relative corrosion resistance. However, significant challenges have prevented their widespread use, and thus, the higher operating temperatures needed for higher-efficiency engines have not been widely achieved. Technical barriers to reaching the high performance objectives have included low fracture toughness, vulnerability to impact resistance, and water vapor accelerated oxidation. Further, the cost of ceramic components has hindered more rapid commercialization. This has resulted in a dwindling supplier base for ceramic components and has highlighted the need for improved materials or coatings to provide environmental protection.
Projects under this program are addressing these challenges. New sources of gas turbine-grade ceramics are being explored, and environmental barrier coatings are being developed. In addition, methods to improve nickel-based superalloys to extend their useful life are also being pursued. Projects being conducted include:
- Kennametal Hot Section Material Development — Russell Yeckley
- Saint-Gobain Hot Section Material Development — Robert Licht
- Environmental Protection Systems for Ceramics in Microturbines and Industrial Gas Turbine Applications
- Part A: Conversion Coatings — Dr. Stephen Nunn
- Part B: Slurry Coatings and Surface Alloying — Beth Armstrong
- Failure Mechanisms in Coatings — Dr. J.P. Singh
- High-Temperature Diffusion Barriers for Nickel-Based Superalloys — Dr. Bruce Pint.
Advanced, high-efficiency microturbines will require improved high-temperature performance and reliability from their recuperators to achieve higher efficiency. This means materials with more oxidation and corrosion resistance and tensile/creep strength at higher temperatures are required. Existing alloy candidates are much too costly, so lower-cost alternatives are being sought. Oak Ridge National Laboratory is working with microturbine manufacturers and material suppliers to develop advanced alloy high-temperature recuperators. Projects addressing this need include:
- Advanced Alloys for High-Temperature Recuperators — Dr. Philip Maziasz
- Recuperator Alloys: Composition Optimization for Corrosion Resistance — Dr. Bruce Pint
- Recuperator Materials Testing — Dr. Edgar Lara-Curzio.
 Waukesha reciprocating engines |
Advanced reciprocating engines will run at higher pressures and higher temperatures and will be required to produce fewer polluting emissions. These demands require that engine materials and pollution-regulating equipment be developed.
The following projects address key needs:
- Advanced Materials for Exhaust Components for Reciprocating Engines — Dr. Philip Maziasz
- Development of Catalytically Selective Electrodes for Nitrogen Oxide and Ammonia Sensors — Dr. T. Armstrong.
With the increasing demand for power electronics to handle more power in smaller packages and challenging environments, the need for improvements in cooling effectiveness is important to product reliability.
 Carbon heat sink on a 133-mhz Pentium chip. |
Specifically, for conventional heat sinks to adequately control the heat loads of advanced, high-efficiency microturbines, they become rather large and heavy. To address this problem, ultra-efficient heat sinks using lightweight, high-conductivity, high-surface-area graphite foam are being developed.
The following project addresses this need:
- Development of High-Efficiency Carbon Foam Heat Sinks for Microturbine Power Electronics — Dr. Ron Ott.
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