An Investigation of the Irradiation Swelling Mechanisms in Refractory Metals at High Temperatures
Abstract
This report presents the results of an investigation of elevated temperature irradiation swelling in refractory metals with an objective of understanding swelling mechanisms in these materials and demonstrating practicality of swelling-resistant materials. The study was divided into three phases. During the first phase, a theoretical model was developed for the swelling in body-centered cubic (bcc) metals. The model was based on chemical reaction rate formalism. Calculations were carried out on on a model material, niobium, which was selected for the study. Experimental and theoretical work was conducted to determine the swelling mechanism. Niobium was irradiated with Nb(++) ions to a dose of 50 dpa and swelling was determined by transmission electron microscopy. A peak swelling at 900C of 7% was observed. No swelling was observed above 1300C. The experimental data were compared to those predicted by the theoretical model. Reasonable agreements were obtained between the experimental and theoretical swelling curve when niobium-oxygen interaction was included. Sink strength ratios were also calculated from the data. The theoretical model was extended during the second phase to include loop growth/ shrinkage in bcc metals. During the third phase of the program, two alloys, Nb- 5Hf and Nb-5W, were irradiated with Nb(++) alone and with Nb(++) + He(+) over a temperature range of 800 - 1350C.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1989
- Accession Number
- ADA211406
Entities
People
- A. T. Taylor
- B. O. Hall
- G. R. Fenske
- J. C. Greggi
- R. Bajaj
Organizations
- Westinghouse Electric Corporation