Structure Evolution and Diffusion During Interphase Boundary Sliding in Binary Eutectics Based on Sn

Abstract

Mechanical behaviour of interphase boundaries (IB) and microstructure in the binary eutectics (Al–Sn, Zn–Sn, Pb–Sn, Cd–Sn) heavily deformed by different schemes and regimes have been investigated. Experiments were carried out on the atomically clean surfaces of alloys and on the bimetallic joints with clean interfaces used as a macromodel of deformed IB. It has been shown that for the eutectics with high IB energy (Al–Sn, Zn–Sn) the interphase boundary sliding (IBS) occurs by means of the dislocation gliding, followed by a remarkable strengthening and accompanied by the formation of narrow stable IB cracks with sharp angles. For eutectics Pb–Sn and Cd–Sn with low IB energy, the IBS occurs as viscous flow and is accompanied by a correlated diffusion along IB. The softening of IB was observed. Intensity of development of the diffusion-controlled accommodation processes on IB depends on the extent of preliminary deformation and values of IB energy.