Multiple deformation processes in polyethylene single crystals

Multiple deformation processes operate when polyethylene single crystals are strained in certain directions. The most complicated processes occur when the crystals are strained along the longest of the axes defining the orthorhombic unit cell of polyethylene. At large strains up to six twinning and martensitic transformation processes can operate, and the textures which result have been studied by selected-area electron diffraction. A description and an interpretation of the diffraction patterns are presented. The results are compared with those obtained in a recent study of deformation processes in bulk specimens of high-density polyethylene with a single-crystal texture (Young and Bowden 1974).