(211) [\bar111] 70/30黄銅単結晶の圧延におけるせん断帯の発達

Abstract

The deformation behavior of (211) [\bar111] single crystals of 70/30 brass during rolling has been examined metallographically from a view point of the deformation mode which is characterized by the development of shear bands.It is shown that a shear band is nearly perpendicular to the side surfaces of the specimen and inclined at 25∼35 deg to the (111) twinning plane. At larger reductions than 40%, at which extensive mechanical twins were nucleated, peculiar slip traces deviated from the (111) plane appear among the slip trace groups of the slip systems having the slip plane parallel to the twinning plane. It is shown that the areas where these peculiar slip traces exist have higher density of mechanical twins and are accompanied by a local lattice rotation of ∼30 deg about the [01\bar1] transverse direction of the specimen. With increasing rolling reductions, these areas are closely arranged so as to form the band-like regions. It is concluded that linear arrangement and accumulation of the peculiar slip traces in these regions cause the formation and development of shear bands.