ON SYMMETRICAL BICRYSTALS AT THE YIELD-POINT IN (110) CHANNEL DIE COMPRESSION

THE GENERAL PROBLEM Of symmetric fee bicrystals in (110) channel die compression is formulated. For crystals at the yield point, corresponding to the beginning of finite multiple-slip and a rigid-plastic model, analytical bounds on the yield-point load are established for all lattice orientations. The upper bound analyses incorporate a deformation field that is motivated by observations from experiment. The bounds are generally good, and are highly satisfactory over approximately two-thirds of the range of possible orientations of the channel constraint direction relative to the lattice axes.