Activation Energies for Creep of Single Aluminum Crystals Favorably Oriented for Cubic Slip

摘要

Creep activation energies for single aluminum crystals favorably oriented for shear by (010) [101] glide were determined over the temperature range from 78°to 900°K. The study was undertaken to determine whether or not the oft reported high temperature cubic slip actually occurs in aluminum. Observations of slip bands on the specimen surface were made in conjunction with the investigation.nFrom 78° to 775°K, the activation energies agreed closely with those previously found for creep by (111) [101] slip, by the Peierls process to 140°K, and by (111) and (111) cross-slip above 260°K. Thus, the coarse wavy slip bands nominally parallel to the (010) plane observed above 260°K were attributed to fine cross-slip on the (111) and (111) planes rather than (010) glide.nFrom 800°to 900°K, unusually high activation energies ranging from 28,000 to 54,000 cal. /mole were obtained. The maximum activation energy was attributed to recrystallization.