Multilayered Metal/Ceramic Composites for Structural Materials Application
EMSL Project ID
46398
Abstract
The design of structural materials for advanced nuclear materials is limited within a window confined by radiation-induced embrittlement at low temperature and creep rupture at high temperature. Extensive efforts are currently underway to develop advanced ferritic-martensitic (F/M) alloys that can be applied at temperature above 600 degC, e.g., oxide dispersion strengthened (ODS) alloys or advanced nanostructured ferritic alloys (NFAs). However, significant challenges remain in materials synthesis at all length scales and atomic scale understanding of the stabilizing mechanisms of oxide precipitates, atomic composition, interface structure and interaction with Fe matrix. In a complementary manner to the common practices of nano-grains or grain boundary engineering to strengthen materials and provide radiation resistance, we propose a research program targeting the development of new structural materials with enhanced radiation, high temperature properties and helium management capabilities that may enable transformational reactor performance. The concept of developing new structural materials is based on the interface engineering of metal/ceramic multilayered composites, in which the interfaces will impede dislocation motion, change the sink strength of point defect recovery, and provide the trapping sites for harnessing helium.
The simplified iron-based bcc steel system will be selected as a model system to demonstrate this concept with the focus on Fe/Y-Ti-O, analogue to NFAs. We will focus on the interface structure design of iron-based multi-layers by thin film deposition approaches and investigate their microstructural stability upon intensive radiation and thermal annealing. The radiation tolerance of these multi-layers will be investigated using energetic beam bombardments in simulating neutron damage and He accumulation. The experiments will be designed and carried out through the utilization of valuable resources at EMSL. The key issues that will be investigated include the interface stability (atomic mixing, dissolution, precipitation or formation of new phases), microstructure evolution, defect/helium behaviors at interfaces and Y-Ti-O and bcc Fe matrix interaction.
The ultimate goals of this research program include: (1) demonstrating the potential and exploring scientific principles of designing new ferritic-martensitic alloys as advanced structural materials based on multi-layer geometry; (2) correlating the characteristics of Y-Ti-O nanoclusters with radiation and high temperature properties by simplifying variables and parameters through well controlled interface design (geometries, orientation, length scale, composition and interface structures); (3) provide insights enabling atomic scale design of radiation tolerant nanostructured composites based on NFAs. The proposed innovative concept of metal/ceramic multilayer design will impact the development of advanced materials with enhanced radiation tolerance, high temperature property and excellent capability for harnessing helium, leading to transformational performance for structural materials for advanced nuclear energy systems.
Project Details
Project type
Exploratory Research
Start Date
2011-11-07
End Date
2012-11-11
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members