Dynamic High Pressure Torsion (DHPT)—A Novel Method for High Strain Rate Severe Plastic Deformation

Proceedings

Verleysen, Patricia¹  Lanjewar, Harishchandra²  Kestens, Leo³ 

[1] Author to whom correspondence should be addressed.;MST, EEMMeCS Department, Ghent University, 9000 Ghent, Belgium;MST-DyMaLab, EEMMeCS Department, Ghent University, 9000 Ghent, Belgium

关键词: dynamic high pressure torsion;    severe plastic deformation;    microstructure;   

DOI  :  10.3390/ICEM18-05399

学科分类：社会科学、人文和艺术（综合）

来源: mdpi

【 摘 要 】

Metals with a fine-grained microstructure have exceptional mechanical properties. Severe plastic deformation (SPD) is one of the most successful ways to fabricate ultrafine-grained (UFG) and nanostructured (NC) materials. Most of the SPD techniques employ very low processing speeds. However, the lowest steady-state grain size which can be obtained by SPD is considered to be inversely proportional with the strain rate at which the severe deformation is imposed. In order to overcome this limitation, methods operating at higher rates have been envisaged and used to study the fragmentation process and the properties of the obtained materials. However, almost none of these methods, employ hydrostatic pressures which are needed to prevent the material from failing at high deformation strains. As such, their applicability is limited to materials with a high intrinsic ductility. Additionally, in some methods the microstructural changes are limited to the surface layers of the material. To circumvent these restrictions, a novel facility has been designed and developed which deforms the material at high strain rate under high hydrostatic pressures. Using the facility, commercially pure aluminum was processed and analysis of the deformed material was performed. The microstructure evolution in this material was compared with that observed in static high pressure torsion (HPT) processed material.

【 授权许可】

CC BY