Dislocation microstructures have been further examined near the crack tip of a compact tension specimen of unirradiated F82H loaded to 25.6 MPa m square root at –196 degrees C after fatigue precracking. A specimen was prepared by sectioning, dimple grinding and ion milling to produce electron transparency just ahead of the crack tip. Further ion milling has allowed improved examination of the microstructure immediately ahead of the crack tip. It is found that subgrain structure is relatively unaffected near the crack tip whereas 3 micron from the crack tip, dislocation loop structure was identified.
Revised: May 1, 2007 |
Published: September 3, 2003
Citation
Gelles D.S., G.R. Odette, and P. Spatig. 2003.FURTHER EXAMINATION OF CRACK TIP MICROSTRUCTURES IN F82H ON THE LOWER SHELF. In Fusion Materials: Semiannual Progress Report for Period Ending June 30, 2003, edited by Ron Klueh and Renetta Godfrey. 56-62. Washington, District Of Columbia:DOE Office of Fusion Energy Sciences.PNNL-SA-39596.