N-situ scanning electron microscopy investigation of recrystallisation kinetics in cold worked nickel

Abstract FRE

In-situ SEM heating and microhardness testing were used to investigate the recrystallisation kinetics ٠/ cold rolled nickel.

The material was deformed to reductions in thickness, e, ranging from 0.25 to 1.12 (s = ln[tj/tf], where t,andtjare the initial and final specimen thicknesses respectively) and then isothermally annealed at 455°c.

'[he Johnson-Mehl-Avranii-Kohnogorov (JMAK) theory was tested and was not found capable " describing the recrystallisation of cold worked metals.

The nteasuredJM/lK exponents «؛،٢ considerably loM’er than the theoretically predicted ones and strongly dependent on the deformation ratio.

Competition between recovery and recrystallisation as well as non random distribution ofnucleation sites are likely ٠؛ be the reasonsfor the discrepancy between the theoretical values and the experimental results.