Accession Number : AD0434112


Title :   RESEARCH CONDUCTED ON SECRETARY OF ARMY RESEARCH AND STUDY FELLOWSHIP TRANSMISSION ELECTRON MICROSCOPY,


Corporate Author : FRANKFORD ARSENAL PHILADELPHIA PA PITMAN-DUNN RESEARCH LABS


Personal Author(s) : Levin,Edwin R


Report Date : Jan 1964


Pagination or Media Count : 86


Abstract : A detailed study was made of prismatic dislocation loops in the bcc refractory metals Nb and Ta. It was found that appreciable densities of dislocation loops can be created in these metals by fatigue deformation. The kinetics of annealing of the loops was studied, and it was found that in both metals the loops anneal out with appreciable time rates at temperatures above 700 C. From the data, the activation energy for self-diffusion could be obtained, and values were derived for both Nb and Ta. (Author)


Descriptors :   *ELECTRON MICROSCOPY , *REFRACTORY METAL ALLOYS , METALLURGY , CRYSTAL STRUCTURE , CRYSTAL DEFECTS , NIOBIUM , TANTALUM , HEAT TREATMENT , FATIGUE(MECHANICS) , DEFORMATION


Distribution Statement : APPROVED FOR PUBLIC RELEASE