The operation of Frank-Read sources, yield stress reversibility and the strain‐rate dependence of the flow stress in the anomalous yielding regime of L12 alloys

摘要: Abstract In the anomalous yield stress regime strain-rate dependence β = (δτ/δ ln ∊) of flow τ is proportional to (τ - τy), where τy identified with required bow out edge dislocations a near-critical Frank-Read source configuration, at level equal that needed for dynamic propagation screw dislocations. The conditions necessary successful operation are discussed. microstrain region predicted form loops elongated along direction. Experiments on ‘partial reversibility’ temperature described; it shown not reversible, but instantaneously ‘partially reversible’. This ascribed instability and ‘running back’ some dislocation in region, unloading. β/τh found reflect different obstacles temperatures. dependences o...