Monte-carlo modeling of microstructural development in Zr grain refined by ECAP

초록

A meso-scale modeling of microstructural development in fine-grained Zr was conducted by a Monte-Carlo method. With the employment of the Equal Channel Angular Pressing (ECAP), a grain size of approximately 200nm was obtained in Zr702 of 200micron in the initial grain size. Based on the high resolution EBSD data of ECA pressed and subsequently annealed Zr, the grain boundary distribution characteristics during grain growth were simulated using a computerized microstructure generated by the Q-state Potts algorithm. A region containing more than 1500 grains was employed during the simulation study. It was found that the annealed microstructure consisted mainly of the high angle boundaries and a strong (0001) texture. During simulated grain growth involving anisotropic grain boundary energy and mobility, the initial misorientation distribution of the grain boundaries persisted while the grain size grew up to 30micron, corresponding to a 175MCS. Concurrently, the strong texture of the initial microstructure was sharpening further during grain growth. A good agreement was realized between the grain boundary character distributions of the experimental microstructure and the computer microstructure.