Advanced materials are vital to higher performance and more economic fossil energy systems. Today, research is focused on developing high-temperature, corrosion-resistant alloys and protective coatings that are compatible with advanced power system high temperature environments, as well as materials that perform specific functions in near-zero emission advanced fossil energy systems that will be developed and implemented in the coming years.

Partnering and cost-sharing with industry are central components of this program area. The Office of Fossil Energy's advanced materials research program also includes projects at national laboratories, universities, and non-profit organizations. The collaborative nature in which this program is implemented enables the inclusion of the best in materials expertise and research facilities from across the United States.

The scope of the Materials program addresses the need for new materials that can withstand higher temperatures and corrosive environments of advanced power generation technologies such as IGCC plants, synthesis-gas-fueled turbines, ultrasupercritical steam cycle plants, oxy-fueled combustors, CO2 sequestration, and fuel cells. The program consists of the following major categories of materials R&D:

Breakthrough Concepts

The objective of breakthrough concepts R&D is to explore new principles and ideas, based on a mechanistic understanding from any discipline, for routes to the development of materials with capabilities significantly beyond those currently available.  The current focus is on innovative approaches to concepts for maximizing the high-temperature capability of alloys. The issues being addressed arise from the facts that (a) many alloys with melting temperatures higher than current alloys have inherent mechanical properties (toughness, etc.) and environmental resistance deficiencies; (b) the potential of these materials can be exploited by application of mechanistic and thermochemical approaches; (c) exploitation of their high temperature capabilities require compromises related to, among other things, the ability to fabricate components, mechanical properties, and environmental sensitivity; (d) ceramics and ceramic composites have exceptional potential, but lack of understanding or databases of composition-structure-property relationships of them have greatly limited the realization of that potential and leads to need for extensive development; and (e) ceramics and refractories suffer rapid environmental degradation in some applications, which imposes the requirement for new approaches to develop increased corrosion resistance with good mechanical properties.

New Alloys

The objective of the R&D in this category is to increase the temperature capability of alloys for use in components required in advanced power plants.  This is accomplished through application of understanding of the relationships among composition, microstructure, and properties.  The current focus is on increased temperature capability/creep strength of conventional alloys and in improved hoop strength and joining of oxide dispersion strengthened (ODS) alloy tubular components.  Steels with improved mechanical properties are being developed to allow the operation of power generation plants using ultra-supercritical steam cycles with steam conditions approaching 760 degrees Celsius and cycle efficiencies exceeding 50 percent. Alloys are being modified to provide the mechanical properties needed in high-temperature, high-pressure "next generation" power plants.  Creep strengthening of promising alloys is being accomplished via techniques such as ODS. A new generation of corrosion resistant high temperature alloys will be developed for the hot components in advanced fossil energy combustion and conversion systems.  Evaluation of the corrosion performance in advanced power generation systems is also included in this R&D category.

Coatings and Protection of Materials

This R&D category is directed to the development of coating materials and processes intended to protect materials from the high-temperature corrosive environments encountered in advanced power generation plants. The current focus is on addressing reliability/lifetime issues in coal combustion and gasification environments and in increasing the high temperature capabilities of materials for use in synthesis-gas-fired turbines. As alloys, as well as ceramics and refractories, are pushed near to and beyond current performance limits and modifications are made to improve their mechanical properties, resistance to environmental degradation, i.e., corrosion, may be compromised. This R&D area is closely coupled and coordinated with the other three research categories included in the program. Researchers are gaining a better understanding of corrosion processes that occurs leading to the selection of new, improved, and more reliable materials.

Ultrasupercritical Materials

The objective of this effort is to develop the materials technology that allows the use of advanced steam cycles in coal-based power plants. The advanced cycles, with target steam temperatures up to 760 degrees Celsius and 5,000psi can increase the efficiency of pulverized coal-fired power plants by as much as nine percent, with an associated reduction of CO2 emissions. The program encompasses both boiler and turbine materials. The scope of the materials evaluation for boilers includes mechanical properties, steamside oxidation and fireside corrosion studies, weldability and fabricability evaluations, and reviews of applicable design codes and standards. The turbine effort includes a full spectrum of testing and evaluation of materials for coatings, rotors, and castings. The work being performed in this area can be applied to many energy systems operating at high temperatures and can be used for retrofit applications in currently operating plants to increase their reliability.