Solute interactions in pure vanadium and V-4Cr-4Ti alloy

Room temperature electrical resistivity and microhardness measurements were performed on cold-worked pure vanadium, solution annealed and cold-worked V-4Cr-4Ti ahoy and fusion weld material over the isochronal annealing tempe rature range from 200 degreesC to 1200 degreesC. The results suggest that T i solutes in the vanadium alloy interact with interstitial O, C and N eleme nts at temperatures of 200 degreesC and higher. This interaction lowers the effective diffusivity of the interstitials in the alloys, which shifts the interaction of interstitials with dislocations to higher temperatures as c ompared to the cold-worked vanadium. Over temperature ranges associated wit h recovery and recrystallization, general trends showed that the hardness d ecreased and resistivity first decreased but then increased in each materia l. Microstructural changes caused by precipitation and by reduction in disl ocation density during. recrystallization may account for most of the diffe rences observed in the measured properties of each material. (C) 2000 Elsev ier Science B.V. All rights reserved.