Mechanical properties, corrosion performance and cell viability studies on newly developed porous Fe-Mn-Si-Pd alloys

Porous Fe-30Mn6Si1Pd (wt.%) alloys were prepared by a simple press and sinter process from ball-milled Fe, Mn, Si and Pd powders blended with 10 wt%, 20 wt% and 40 wt% NaCl to obtain different degrees of porosity. For comparison purposes, a bulk fully-compact Fe-30Mn6Si1Pd alloy was produced by arc-melting and subsequent copper-mold suction-casting. While the porous Fe-30Mn6Si1Pd alloys only consist of γ-austenite, their fully-compact counterpart comprises ε-martensite and γ-austenite phases. In all cases, the low magnetic susceptibility response assures good compatibility with nuclear magnetic resonance and magnetic resonance imaging techniques. Furthermore, a reduction of the Young's modulus, from 55 to 7 GPa, was attained by introducing porosity. The biodegradation performance was evaluated by static immersion and electrochemical corrosion tests in Hank's solution. The influence of immersion time on composition, microstructure, mechanical and magnetic properties was assessed. While introducing porosity renders alloys with suitable mechanical and magnetic properties, it also has a detrimental effect in terms of cell viability. Hence, the porosity level needs to be controlled in order to obtain alloys with an optimized performance