抄録
Uniaxial tension tests were carried out using Nylon 6 which is a typical thermoplastic resin. The surface roughening during plastic deformation was investigated with a stylus instrument and the change in the microscopic surface profile was observed by a scanning electron microscope. The surface roughness increased in proportion to the applied plastic strain until the beginning of the necking of the specimen. After that the rate of increase of the surface roughness with increasing strain gradually slowed down. It was found that the degree of crystallinity was an important factor for the surface roughening during plastic deformation. The initial surface roughness of specimen also affected the surface roughness. The specimen thickness from 2mm to 6mm had little effect on surface roughening. The surface roughness in the loading direction was smaller and had larger wavelength than that in the transverse direction. Macro-fibrils, that is, fibrous structures were observed on the plastically deformed surface. The measured surface roughness was considered to consist of the irregularity between neighbouring macro-fibrils and the irregularity caused by the motion of group of macro-fibrils.
