On Slip and Yielding of Alloys with Lamellar Microstructures.

The flow behavior of an alloy with a two-phase lamellar microstructure is analyzed. Based on the model presented, the macroscopic slip system and the yield strength are controlled by the ability of a slip system, once activated in the softer phase, to shear the plate-like harder phase. This ability to shear is controlled by the capacity of a specific slip system, together with the applied stress, to generate sufficient shear stress through the thickness of the harder phase to cause macroscopic flow. The yield stress and active macroscopic slip plane of an individual Widmanstatten colony of alpha-beta Ti alloy are analyzed to demonstrate the model. Comments are also made regarding the deformation of and crack formation in pearlitic steels in terms of the proposed model. Author