A PROGRAM OF RESEARCH ON MECHANICAL METALLURGY AS RELATED TO FUEL-ELEMENT FABRICATION. Quarterly Progress Report for the Period Ending June 30, 1961

Results of crawing experiments using 3/8-in. bars to provide rod and tube test specimens are reported. In mechanical metallurgy investigations on the relation of formability to imperfection structure the peierls potentials for dislocation of Nb, Mo, Ta, and W were measured. Design and construction of a microextensometer reported. The investigations of the effects of grain size on the stored energy cold work were extended to a new lot OFHC Cu. In studies of formability relations with imperfection structure, a detailed study is reported on the internal-friction relaxation spectrum of Ta relatively unmodified by impurities. A summary of interstitial impurity effects on the internal-friction of Ta is given. (J.R.D.