Plastic deformation of polyethylene crystals

Polyethylene single crystals attached to a copper substrate were plastically deformed at −196°C and 20°C. Slip lines were observed at all temperatures on the surface of the crystals. The observations suggest that plastic deformation in polyethylene crystals may occur by crystallographic slip due to the movement of dislocations with Burgers vector parallel to the [001] direction. At low temperatures plastic deformation seems to occur by slip only; at high temperatures thermally activated deformation processes may be superimposed. Some results on interlamellar deformation processes are reported.