Accession Number : AD0433492


Title :   GENERAL RESEARCH, CREEP OF NIOBIUM AT LOW TEMPERATURES,


Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF


Personal Author(s) : Stone,G A ; Conrad,H


Report Date : 21 Feb 1964


Pagination or Media Count : 25


Abstract : The activation energy, the activation volume, and the frequency factor for the plastic deformation of niobium at low temperatures were derived from creep tests. These values are in excellent agreement with those derived from constant strain rate tests, indicating an equivalence between the two types of testing. The present results support the idea that overcoming the Peierls-Nabarro stress is the rate-controlling mechanism during the plastic deformation of the BCC metals at low temperatures. Using the models of Seeger and of Dorn and Rajnak the kink energy in niobium is calculated to be 0.34 to 0.40 eV. (Author)


Descriptors :   CREEP , NIOBIUM , HEAT OF ACTIVATION , STRESSES , PLASTIC PROPERTIES , DEFORMATION , CRYOGENICS , TEMPERATURE


Distribution Statement : APPROVED FOR PUBLIC RELEASE