QUANTIFYING RECRYSTALLIZATION NUCLEATION AND GROWTH-KINETICS OF COLD-WORKED COPPER BY MICROSTRUCTURAL ANALYSIS

Microstructural evolution data describing the recrystallization of col d-worked copper at 394 K (121 degrees C) were obtained by quantitative metallography using scanning electron microscopy and electron backsca ttered pattern analysis. Using the microstructural path method (MPM), a new analytical representation of the microstructure was devised that emulated all the measurements and successfully explained why simpler representations failed to adequately describe the kinetics of recrysta llization in copper. Saturation of preferentially located nucleation s ites such as at deformation bands, grain boundaries, etc., where recry stallized grains may cluster in planar arrays before the deformed volu me is completely consumed, and time-dependent growth rates matched ful ly the kinetic behavior of copper during recrystallization. The kineti c behavior of individual texture components (random and cube + cube tw in) was also delineated, experimentally and analytically. Precise matc hing of the analytical representation of the microstructure to experim ent allowed calculation of nucleation and growth parameters. These sho wed that the cube + cube twin grains nucleated at a faster rate than t he random grains, that site saturation occurred sooner for the cube cube twin grains, and that cube + cube twin grains grew at rates about 1.5 times faster than the random grains. The calculations suggested t hat as recrystallization approached completion, the number of random g rains slightly outnumbered the cube + cube twin grains.