Impurity Atom-Dislocation Interactions and Subsequent Effects on Mechanical Properties of Refractory Metals

摘要

The interaction between dislocations and impurity atoms in electron beam refined arc-cast molybdenum single crystals was studied in the form of strain aging and tensile creep experiments. Data was obtained on the kinetics of the return of the yield drop process for molybdenum containing carbon in the temperature range from 475-650C. This data yielded an activation energy of 21,400 cal/mol for the process. A comparison is made of this with other published values. A Mo-1%Ta alloy was also examined but strain aging effects were not observed. The tensile creep behavior of molybdenum containing carbon was compared with that for purity material. The presence of carbon greatly increased the creep resistance while a polygonization treatment slightly decreased the creep resistance. The tendency for substructure to coarsen was found to be less in molybdenum containing carbon than in high purity material. (Author)