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Original Date: 11/03/1996
Revision Date: 01/18/2007
Information : Residual Stress Management
Residual stress knowledge provides a critical key to component life prediction and failure analysis. Both macro (long range) and micro (short range) residual stresses can be independently characterized by diffraction methods. As a national resource for residual stress knowledge, the High Temperature Materials Laboratory (HTML) at Oak Ridge National Laboratory (ORNL) uses various diffraction methods that are applicable to polycrystalline materials including alloys; ceramics; thin films and coatings; and composites.
Neutron diffraction macro residual stress mapping, a unique capability at ORNL, uses the highest flux research reactor in the United States. This capability addresses design, life prediction, and component failure issues. In addition, neutron powder diffraction methods can measure micro residual stresses as a function of temperature.
X-ray diffraction typically determines near-surface measurements. However, the HTML has developed special x-ray diffraction capabilities to solve problems associated with curved-surface measurements (down to a 6 millimeter radius) and non-destructive subsurface stress gradient measurement in ground ceramics and coatings. Additional x- ray diffraction capabilities include two dedicated, four-axis, high-precision goniometers; 2-D and 3-D strain and texture mapping; and grazing incidence x-ray diffraction for subsurface and thin film residual stress profiling.
The HTML’s Residual Stress User Center offers organizations an opportunity to work with experienced personnel, state-of-the-art facilities, and high-precision equipment. Capabilities provided by the Center include finite element modeling; quantitative crystallographic texture analysis; elastic moduli analysis; retained austenite and phase analysis; depth profiling of stress; stress dependence on temperature; and load transfer between phases of composites.
Customers can utilize the Residual Stress User Center at no charge provided their research work is non-proprietary and co-published with ORNL. For proprietary work, the Center charges a fee. ORNL has assisted many industrial, government, and academic organizations in material characterization and residual stress analysis.
For more information see the
Point of Contact for this survey.
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