Recovery of High‐Temperature Creep‐Resistant Substructure in Rutile

Recovery of creep‐resistant substructure in rutile was studied at 1000°, 1020°, and 1040°C. Specimens were crept under a stress of 10,000 psi to a strain early in the secondary stage of creep and then allowed to recover for varying periods under a residual stress of 400 psi. Recovery was detected by the increased creep strain which occurred when the 10,000 psi stress was reapplied. An apparent activation energy of 135,000 cal/mol was obtained for the recovery process. Experimental evidence suggests that the primary recovery mechanism involves the sweeping out of dislocation barriers within the material by the migration of dislocation walls or subgrain boundaries.