The demand for structural metallic materials is increasing continuously especially in load-bearing applications in key sectors such as energy, construction, machining and transportation. Steel is one of the most important, multi-functional and adaptable of structural materials. Steel compared to other materials of its type has low production costs and provide unique characteristics, such as: strength, hardness, weldability, suitable machineability and corrosion resistance. These characteristics make steel very vital in most industries.

On the other hand, self-healing can be defined as the ability of a material to heal / recover / repair damages automatically. There are different approaches toward self-healing of metals, that can be separated to two major categories, those are: 1) autonomous healing methods that depend on intrinsic mechanisms, and 2) assisted healing methods that need an external intervention.

Recently, computational methods have gained a wide application to study self-healing in metals using molecular dynamics (MD) and finite element (FE) methods. These methods can be used to demonstrate and optimize different metallic alloys potential to self-heal, and to further tailor these metallic structures toward improving their mechanical and fracture properties through self‐healing. Nevertheless, computational studies of self‐healing phenomenon in metals have been small in number and scope till recently. 

Therefore, the current paper starts with a general introduction of different mechanisms of intrinsic self-healing in metallic structures. The paper highlights previous studies using different experimental and computational approaches to explore self-healing in metallic systems, while focusing on Iron/Steel alloys. Furthermore, the paper present authors work to study self-healing and its impact on mechanical properties of Iron.

In this work, simulations were carried on bi-crystalline iron sample to investigate the effect of alloying elements diffusion (solid state diffusion) on the fracture / healing properties of iron alloys and their impact on its mechanical properties. The intergranular crack is produced by applying tensile stress on the bi-crystalline sample. Then the effect of the alloying elements diffusion on healing is studied upon stress application after annealing at different temperatures, including room temperature. Different samples been compared to healthy samples, and cracked samples without self-healing, to demonstrate the effectiveness of self-healing in Iron alloys.

References:

1- Niels van Dijk and Sybrand van der Zwaag. (2018), Self-Healing Phenomena in Metals, Adv. Mater. Interfaces 2018, 5, 1800226.

2- Michele V. Manuel, Principles of Self-healing in Metals and Alloys: An Introduction.

3- S. M. He, N. H. van Dijk, H. Schut, E. R. Peekstok, and S. van der Zwaag. (2010), Thermally activated precipitation at defor-mation-induced defects in Fe-Cu and Fe-Cu-B-N alloys studied by positron annihilation spectroscopy, Phys. Rev. B 81, 094103.


Intrinsic Mechanisms of Self-Healing in Metallic Structures

Division / Sponsors: 
Aerospace, Bioengineering, Applied Mechanics, Design Engineering Division, Advanced Energy Systems, Manufacturing Engineering Division, Noise Control and Acoustics, Nondestructive Evaluation, Diagnosis, and Prognosis (NDPD), Nuclear Engineering Division, Process Industries Division, Fluids Engineering, Heat Transfer, Materials, Microelectromechanical Systems, Safety Engineering and Risk Analysis, Computers & Information in Engineering


Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2020/volume/84478

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