Development of high-performance nanostructured aluminum and its constitutive modeling

Abstract

A new technique, an in-situ hot-extrusion-based synthesizing process, is proposed to develop high-performance nanocrystalline aluminum (nc-Al) with an optimally tuned strength-to-ductility ratio suitable for various technologically relevant applications. Comprehensive investigations are conducted by characterizing mechanical and microstructural properties to realize the influence of various synthesizing variables on the properties of the bulk nc-Al. Furthermore, a continuum-scale constitutive modeling approach is proposed based on dominant microstructural mechanisms of plastic deformation and implemented into a finite element solver using a user-defined material interface. It is shown that the proposed theory can provide a versatile platform to predict the nanocrystalline aluminum mechanical response quite well.

Keywords:

• Nanocrystalline metal
• high-energy ball milling
• constitutive model
• finite element analysis
• mechanical properties

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 The notation $\mathbf{A}$ stands for a second-order tensor with ${\mathit{A}}^{\top }$ as the transpose of $\mathbf{A}.$ The quantities, $\mathrm{tr}\mathbf{A},$ $\mathrm{dev}\mathrm{ }\mathbf{A}=\mathbf{A}\mathbf{ }- (1/3)(\mathrm{tr}\mathrm{ }\mathbf{A})\mathbf{I}\mathbf{ }$ and $\left|\mathit{A}\right|= \sqrt{\mathit{A}\mathit{ }:\mathit{A}}$ denote the trace of tensor $\mathbf{A},$ the deviatoric part of tensor $\mathbf{A}$ and the magnitude of tensor $\mathbf{A},$ respectively, such that $\mathbf{A}\mathbf{ }:\mathbf{A}=\mathrm{tr}\left({\mathbf{B}}^{\mathbf{\top }}\mathbf{A}\right)$ denote the scalar product of two second-order tensors $\mathbf{A}$ and $\mathbf{B}.$ The vectors $\mathbf{X}$ and $\mathrm{x}$ represent the reference position and current position, respectively.

Additional information

Funding

S.D., A.M., M.G., and P.T. sincerely acknowledge the financial support from ASEAN-Indian Science and Technology Development Fund (AISTDF), DST, Govt. of India, under Grant No. IMRC/AISTDF/R&D/P-14/2018. F.M. acknowledges the partial support provided by the AGÜ foundation.