It's a method to determine the grain size in established channel angular
extrusion process. First, analyze the displacement of finite element in established channel angular
extrusion process, determine the node displacement through the center differential, compute the strain through the relationship between strain and displacement, get the stress in according to the elastic constitutive relationship, map to the grain slide project and line to get the
crystal grain the
shear stress within the grain and on the boundary, compute the
shear stress within the
crystal grain and on the boundary, if not exceed the critical
shear stress, the grain size is not changed, or compute the new
dislocation density and grain size; according to the
dislocation coupled differential equations determine the
dislocation density increment within the grain and on the boundary from corresponding
shear strain rate, updating the dislocation density, and compute the grain size in current state through the dislocation density. The invention can get the grain size of
extrusion material in repeated multiple times deformation processes, and provide the corresponding angle grain size extrusion, extruded times and other design parameters references to extrusion technology.