DYNAMIC GRAIN GROWTH DURING SUPERPLASTIC DEFORMATION

摘要

Superplastic deformation (SPD) causes the accelerated anisotropic grain growth. This process results in the formation of structure which is quasistable during superplastic deformation and unstable after deformation. The degree of instability is determined by the size of grains, their shape coefficient which depends on the nature of an alloy and is equal to 1.1 -1.5 after SPD, and by the unbalance of triple junctions at boundaries. Alloying of metals can affect the thermodynamic force and mechanism of dynamic anisotropic grain growth and correspondingly influence the parameters of superplasticity in alloys.