Dr Suresh Neelakantan

Mechanical and Magneto-mechanical characterisation of stainless steel fibre network materials

Stainless steels exhibit good biocompatibility apart from possessing high corrosion resistance and toughness. My post-doctoral research work is to primarily evaluate the mechanical and magneto-mechanical characteristics of stochastic stainless steel fibre network assemblies intended for biomedical implant applications. Such fibre networks (70-90% porosity) can be produced by solid-state sintering (Fig.1).

The study is mainly focused on 316L austenitic (non-magnetic, low C content) and 444 ferritic (magnetic, nickel-free, low C and N content) grades of stainless steels. Mechanical testing, both on individual fibres and on fibre networks, is being carried out to evaluate their elastic, plastic and fracture characteristics. The stress-strain response of single fibres depends on alloy composition (Fig. 2). In sintered fibre networks, experiments are being carried out to measure their in- and out-of-plane elastic properties, yield strength and fracture energies (Fig. 3).

Further work will focus on quantifying the significance of the network architecture (fibre orientation, fibre segment aspect ratio etc.) in terms of its effects on the elastic properties, fracture characteristics, fatigue and magnetic response of these fibre network materials.