Dislocation-solute atom interactions in alloys. Technical progress report, February 1, 1975--January 31, 1976

New results were obtained in two major project areas: (1) surface oxide softening and solute gradients in niobium and tantalum, and (2) mechanical properties of Nb--H and Nb--D alloys. The important results include: (a) observation and characterization of an extremely large softening and ductilizing effect of bcc metals (niobium and tantalum) by application of thin (500 to 1000 A) oxide films coupled with injection of a high density of mobile dislocations; (b) determination of the relative strengthening ductility changes caused by hydrogen and deuterium in niobium. (auth