Investigation of Grain Refinement Mechanism of Nickel Single Crystal during High Pressure Torsion by Crystal Plasticity Modeling

Materials

Guanyu Deng¹  Wei Wang²  Hao Zhou²  Huaiju Liu²  Caichao Zhu²  Peitang Wei² 

[1] School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, Wollongong NSW 2522, Australia;State Key Laboratory of Mechanical Transmissions, Chongqing University, Chongqing 400044, China;

关键词: high pressure torsion;    crystal plasticity;    grain refinement;    microstructure;    lattice rotation;   

DOI  :  10.3390/ma12030351

来源: DOAJ

【 摘 要 】

The excellent properties of ultra-fine grained (UFG) materials are relevant to substantial grain refinement and the corresponding induced small grains delineated by high-angle grain boundaries. The present study aims to understand the grain refinement mechanism by examining the nickel single crystal processed by high pressure torsion (HPT), a severe plastic deformation method to produce UFG materials based upon crystal plasticity finite element (CPFEM) simulations. The predicted grain maps by the developed CPFEM model are capable of capturing the prominent characteristics associated with grain refinement in HPT. The evolution of the orientation of structural elements and the rotations of crystal lattices during the HPT process of the detected differently oriented grains are extensively examined. It has been found that there are mainly two intrinsic origins of lattice rotation which cause the initial single crystal to subdivide. The correlation between the crystallographic orientation changes and lattice rotations with the grain fragmentation are analyzed and discussed in detail based on the theory of crystal plasticity.

【 授权许可】

Unknown