Steady state and a general scale law of deformation

38th Risø International Symposium on Materials Science

Huang, Yan^1

BCAST, Brunel University London, Uxbridge, United Kingdom^1

关键词: Characteristic properties;    Deformation conditions;    Essential features;    Grain boundary dislocation;    Hall-Petch relation;    Intrinsic property;    Steady state deformation;    Steady-state values;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/219/1/012029/pdf
DOI  :  10.1088/1757-899X/219/1/012029

来源: IOP

【 摘 要 】

Steady state deformation has been characterized based on the experimental results for dilute single-phase aluminium alloys. It was found that although characteristic properties such as flow stress and grain size remained constant with time, a continuous loss of grain boundaries occurred as an essential feature at steady state. A physical model, which takes into account the activity of grain boundary dislocations, was developed to describe the kinetics of steady state deformation. According to this model, the steady state as a function of strain rate and temperature defines the limit of the conventional grain size and strength relationship, i.e., the Hall-Petch relation holds when the grain size is larger than that at the steady state, and an inverse Hall-Petch relation takes over if grain size is smaller than the steady state value. The transition between the two relationships relating grain size and strength is a phenomenon that depends on deformation conditions, rather than an intrinsic property as generally perceived. A general scale law of deformation is established accordingly.