Deformation of high density polyethylene by dynamic equal-channel-angular pressing

作者：Wu, Xiangji; Pu, Lin; Xu, Yunfei; Shi, Jinchun; Liu, Xiaoyi; Zhong, Zhengye^*; Luo, Sheng-Nian^*

来源：RSC Advances, 2018, 8(40): 22583-22591.

DOI：10.1039/c8ra03366h

• SIMPLE SHEAR DEFORMATION
• X-RAY-DIFFRACTION
• PLASTIC-DEFORMATION
• TEXTURE EVOLUTION
• STRAIN-RATE
• MECHANICAL-PROPERTIES
• COMPRESSIVE BEHAVIOR
• POLYCARBONATE PLATE
• TIME-TEMPERATURE
• EXTRUSION

The effect of high strain rate and large shear deformation on the orientation of crystallites in high density polyethylene (HDPE) was investigated with dynamic equal-channel-angular pressing (D-ECAP). The HDPE samples were processed by two loading routes, route A and route C. Grid lines were used to obtain macroscopic strain distributions, which were substantiated by finite element modeling. Owing to the strain rate effect, the number of D-ECAP processing passes has a minor effect on the shear strain accumulations compared to ECAP. D-ECAP leads to a decrease in the thickness of the crystalline stem, and the crystallinity. After route-A or route-C D-ECAP processing, a new monoclinic phase emerges, and two types of crystallographic c-axis orientations appear: the crystallographic c-axis is approximately parallel to the flow direction (FD), or is tilted at approximately 55 degrees clockwise away from FD. However, only one type of crystallographic c-axis orientation is detected after 2 passes of route-C D-ECAP. It is viable to utilize D-ECAP to control the structure and orientation of crystalline polymers, as a complement to ECAP and other processing techniques.

• 出版日期2018
• 单位西南交通大学